Overheating Early Warning System

[nk_zhp]

Hi clan,

Hope everyone is doing well.
I've been contemplating an idea of building an early warning system, which will send an audible signal to the driver when the coolant temperature goes above normal. I think the device can be made relatively inexpensive.

Great idea?
Good idea?
Ok idea?
Nah, find something better to do.

Brutal honesty is much appreciated.

[kayger12]

Sounds like a cash cow. I think it's a great idea.

I know a lot of us look at the temp gauge more than the speedo, but by the time you see it overheating, it's likely too late...

[gr330zhp]

Pretty good idea!

The thing with newer BMWs is the coolant tanks get smaller and smaller, so by the time you see its hot, youve lost most of the little coolant it had. Older BMWs had much bigger tanks...

[danewilson77]

Great idea. The temp sensor range we have right now (the gauge), has a huge band in the middle.....so if it leaves the 12 O clock position...you know your in the sheeeeets and most don't catch it.

[pyreguy]

I would be very interested in this
....in fact I am


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[billschusteriv]

Also interested.

What are you considering? Moving the sensor? Installing a process controller that displays a digital value and sounds an audible alarm once a temperature or temp rise is reached?

[mimalmo]

Awesome idea.

[nk_zhp]

@billschusteriv - There are couple of approaches on the table. One thing I definitely do not plan on doing is an LCD readout of the temp. As soon as you introduce a display component the price and complexity goes up. In fact there are many products out there that will read out the temp from the ODBII.

[spencers]

@billschusteriv - There are couple of approaches on the table. One thing I definitely do not plan on doing is an LCD readout of the temp. As soon as you introduce a display component the price and complexity goes up. In fact there are many products out there that will read out the temp from the ODBII.

Are you versed in Arduino coding?

[nk_zhp]

Are you versed in Arduino coding?

I have never done anything on that platform, but have seen a variety of project utilizing it. I can certainly see its application in this case.

[jjcools]

Must have...

[MasterC17]

The easiest way would be to do something like what I did with my Oil Pressure Warning Light. For example this one (http://www.egauges.com/vdo_indS.asp?Sender=250F_120C_VDO&PN=323-099B): has a warning contact for 217f+. Find a place to mount it and run a wire to a warning light and you're set. In fact, I may look into actually doing this - I'm well versed in this type of thing at this point.

[nk_zhp]

The easiest way would be to do something like what I did with my Oil Pressure Warning Light. For example this one (http://www.egauges.com/vdo_indS.asp?Sender=250F_120C_VDO&PN=323-099B): has a warning contact for 217f+. Find a place to mount it and run a wire to a warning light and you're set. In fact, I may look into actually doing this - I'm well versed in this type of thing at this point.

Oil pressure switch is a switch and not a sensor, meaning its continuity is either 0 or infinite. So wiring into a warning into it isn't difficult. What would the equivalent process be for the temp?

[MasterC17]

Oil pressure switch is a switch and not a sensor, meaning its continuity is either 0 or infinite. So wiring into a warning into it isn't difficult. What would the equivalent process be for the temp?

I used an oil pressure sensor with a warning switch on it. I'm not sure how you could do this to say the factory temp sensor in the lower hose though that would be ideal. EDIT: J/K

[danewilson77]

You think exp tank temp is representative of coolant flow temp in the jackets?

[nk_zhp]

Radiator hose or the cap for that matter are inconsistent places to sample temperature. The reading there heavily depends on what part is functioning and what parts isn't (for example, failed pump will cause the radiator hose reading to be normal because water is not circulating). The sensors in that area are used strictly to control the fan. The ECU disregards the reading from there for purposes of fuel mixture regulation and/or instrument cluster display.

[MasterC17]

You think exp tank temp is representative of coolant flow temp in the jackets?

Radiator hose or the cap for that matter are inconsistent places to sample temperature. The reading there heavily depends on what part is functioning and what parts isn't (for example, failed pump will cause the radiator hose reading to be normal because water is not circulating). The sensors in that area are used strictly to control the fan. The ECU disregards the reading from there for purposes of fuel mixture regulation and/or instrument cluster display.

Hehe good point, totally forgot to consider that. Oil circulates through the cylinder head correct? The fact that BMW didn't put something like this in the car in the first place is ridiculous.

Trying to figure out if this is the sensor that monitors water temp (#3): http://www.realoem.com/bmw/showparts.do?model=BD53&mospid=47713&btnr=11_2169&hg=11&fg=15&hl=7

[pyreguy]

BMW.....ridiculous

Blasphemy!! :rofl


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[danewilson77]

Name one car that does have an early detection system.

[nk_zhp]

BMW engineers believed that if you failed to watch the temp gauge continuously and let the car overheat you deserve to have a damaged engine :)

The truth is that the engine will run for a few minutes in red and still be functional. However it's impossible to tell just how much negative effect it had on it. Most likely it will function fine but it might go 20K less before needing a rebuild. On newer cars (e9x) every warning is accompanied by a beep and a large icon display in the middle. So they sort of addressed this issue later. The same problem as on E46s exists on me E30 M3. My belt ripped and I noticed it just a tick before the red zone. Funny enough, only a minute earlier it was in the middle. So when the pump stops, the temp climbs rather quickly. After that experience I had the uneasy feeling of not knowing if there was any damage.

[MasterC17]

I feel there's a fair amount of people who wouldn't notice in an E46 until the car blew itself up. It's my opinion that all cars should have a giant red flashing light accompanied with loud annoying beeping if the car starts overheating. Of course, none will do that but at least on the E9(X) they had something better than the E46 which has next to nothing. I overheated mine during the re-build after installing the new cooling system (improper bleeding). I didn't notice until it was a fair way into the red. As far as I can tell the only negative has been the valve cover gasket leaked which I replaced. Regardless, I don't want that to ever happen again.

Using a system that takes the reading from the ECU may be the easiest way to do this after all - unfortunately I have no idea how you would do this as the only coding I can do is on the interweb.

[M54Dave]

I would go for something like this, I think something that made a sound would be the best route. I had a Jetta that overheated when a waterpump went, once the coolant stops flowing a car will over heat rather quickly. The jetta was fine one moment, overheated the next. The jetta did beep, but that was once it was already in the red, it would have been great to hear a beep as soon as the temps started to rise. I try to watch the gauge as much as I can but in the case with the Jetta it was in traffic and the car only had 28k on it (defective pump.)

[nk_zhp]

By BMW's specs the range of 75C - 113C is considered normal. When the temp is in this range, the needle is hard set in the middle. It won't fluctuate with changes as long as they are in this range. Once the temp reaches 113C the needle shoots to the 3/4 mark and becomes "real". Frankly, at this instance, I would take a loud, annoying beep over the possibility of an overheat.

[pyreguy]

I like the idea of the sound warning coming into play as soon as the temo got above "normal" but before it gets into the red.... If you guys make this happen I will certainly be a customer...

[3ZHPGUY]

That Gage is stupid. There is NO warning at all, once the car worms up it stays at 12:00 and never moves beyond until it's to late. I have had it go up on me also before I knew how to bleed the system properly. A short ride around the block and all looked good and then it hit. The gage immediately barred itself to hot. There is no slow move it's just 12:00 or buried HOT. Even when I finish a track session the gage is at 12:00. So it doesn't matter if you watch the lame a....sssss thing or not. If something goes wrong with the cooling system you will probably hear the cap blowing off and see steam before you notice the gage.

The only good warning is the low coolant warning. That tells you you there is a problem that you need to get checked. If you drop a water pump you're instantly dead and need a tow, same goes for a expansion tank failure.

[MasterC17]

By BMW's specs the range of 75C - 113C is considered normal. When the temp is in this range, the needle is hard set in the middle. It won't fluctuate with changes as long as they are in this range. Once the temp reaches 113C the needle shoots to the 3/4 mark and becomes "real". Frankly, at this instance, I would take a loud, annoying beep over the possibility of an overheat.

I don't understand how BMW thinks anything over 105C is 'normal'.

[spencers]

Perhaps some coding can be done, similar to how the ambient temp sensor fires the beep at 37*F. Heck, maybe even repurpose it... Except pull the temperature data from the coolant temperature sensor.
I remember seeing the option to turn on/off the stupid ice warning in SSS/Progman.
http://img189.imageshack.us/img189/2089/icefa.jpg

[3ZHPGUY]

It's probably the range that the computer can adjust for.

If it's running to cool, the computer compensates and is still runs but it will be cold inside

If it's running in range, no problem

If the expansion ruptures, you loose coolant temp goes up and Service Engine light comes on, you stop

If the pump fails, belts come off and all lights come on, you stop

If coolant is leaking, your low coolant light comes on. The earliest detection of a problem, get it fixed

So what other failure would put the needle hotter but still drivable enough to create damage?

[MasterC17]

Perhaps some coding can be done, similar to how the ambient temp sensor fires the beep at 37*F. Heck, maybe even repurpose it... Except pull the temperature data from the coolant temperature sensor.
I remember seeing the option to turn on/off the stupid ice warning in SSS/Progman.

I keep wondering if it's possible to do some real coding/editing using NCS Expert. Maybe someone could try using that or looking through it to see if it's possible.

[spencers]

I keep wondering if it's possible to do some real coding/editing using NCS Expert. Maybe someone could try using that or looking through it to see if it's possible.

I pinged TerraPhantm, who said he remembers seeing an option in NCS to set an audible warning for coolant temperature and that he'll look into it.

Could be a nice feature!

[MasterC17]

I pinged TerraPhantm, who said he remembers seeing an option in NCS to set an audible warning for coolant temperature and that he'll look into it.

Could be a nice feature!

That would be excellently awesome!! We may have found a solution :)

[nk_zhp]

I pinged TerraPhantm, who said he remembers seeing an option in NCS to set an audible warning for coolant temperature and that he'll look into it.

Could be a nice feature!

As far as I know that option is not available. But I could certainly be dead wrong.

[nk_zhp]

Sorry, I missed this post yesterday.

There are a couple of scenarios where temp warning can be useful.

1. Radiator fan malfunction while the car is not moving quickly enough to induce substantial air flow through the radiator. In fact this is exactly what happened to me when I got my brand new 2001 330i Sport a decade ago. Some of you might recall, there was a huge fan recall affecting 3 and 5 series cars, which in some cases caught on fire. I was sitting in a parking garage waiting to pick a friend from work and next thing I know the red light on the temp comes on. I was lucky to be in an enclosed darker space so the light caught my eye. If the sun was beating down on my dash I would have not seen it.

2. An obstruction on the front grill preventing air flow. Funny enough about a month ago I was reading a post on E46Fans from a guy who's car was overheating in snow conditions because the snow was packing onto the front grill.

3. Thermostat stuck close

4. Other internal problems affecting water flow.

I agree with you, that an exploded expansion tank will probably be noticed via other means. Though, that said, I've seen numerous post regarding this problem which contained a statement "and the needle was pegged all the way to the right" ... if that's the case, how did these drivers allow the problem to get that far.


p.s., pump failure can be such that the belt stays on BTW. Some pumps have an internal failure of the impeller, while the bearing themselves are functioning fine.



It's probably the range that the computer can adjust for.

If it's running to cool, the computer compensates and is still runs but it will be cold inside

If it's running in range, no problem

If the expansion ruptures, you loose coolant temp goes up and Service Engine light comes on, you stop

If the pump fails, belts come off and all lights come on, you stop

If coolant is leaking, your low coolant light comes on. The earliest detection of a problem, get it fixed

So what other failure would put the needle hotter but still drivable enough to create damage?

[Mike V]

It would be awesome for the track. My E36 M3 went through on-track overheating issues for a bit and sometimes I wouldn't notice the gauge until it was beyond the 3/4 mark.

[ryankokesh]

This improper bleeding problem I'm hearing mentioned is starting to scare me (just replaced pump and did this yesterday). If you don't mind me asking, what did you guys do or not do that made it overheat?

I'd definitely be interested in some type of early warning system though.

[MasterC17]

This improper bleeding problem I'm hearing mentioned is starting to scare me (just replaced pump and did this yesterday). If you don't mind me asking, what did you guys do or not do that made it overheat?

I'd definitely be interested in some type of early warning system though.

Mine was just very hard to bleed because I had next to no coolant in the engine when I re-filled it. I just didn't bleed it long enough/well enough. After doing a coolant flush just make sure you pay attention to the gauge, you'll know if there's a problem pretty quickly. If it doesn't overheat after the first drive I wouldn't worry about it.

[kayger12]

I'm thinking probably just put coolant in the exp tank and didn't turn the key to position 2, heat high, fan low, bleed screw open...

Droid X. Tapatalk. Use it.

[ryankokesh]

Good to know...think I'll be okay :)

[MrMaico]

I would sure be interested in something like this. I have to admit that I'm not very good about scanning my gauges as often as I should. I wish the Leatherz gauge kits came with a coolant temp gauge. I have to wonder why not? Must be some reason, I have to assume there just isn't a good way to get a sending unit installed in a proper location. You would think that something could be worked out though.:dunno

The day I bought my car, in Vegas, it was 102 degrees out and before leaving the dealer lot I sat for about 15 minutes with the a/c going while I made a couple of calls to confirm I had insurance. Of course I kept a close eye on the temp gauge and it never moved but if I had known how our gauges work back then I would never have done that!

My 1990 Yamaha 90hp outboard engine came with a digital tach/fuel gauge with some idiot lights in it and if the engine started overheating a light would come on and it would go into a limp mode. Too bad BMW didn't do something like that.

Barry

[static667]

I'm thinking that a warning light to accompany the buzzer would be helpful, too.

Sent from my rooted Fascinate. Hacked Droid FTW!

[spencers]

I'm thinking probably just put coolant in the exp tank and didn't turn the key to position 2, heat high, fan low, bleed screw open...
Don't forget to jack up the front end.

After that, jack the front of the car up, start it, (turn heater on as you described) and bring it up to operating temp. Crack the bleeder screw every now-and-then. If you hear air coming out, keep doing it. When you see fluid stream out, rather than air bubbles, you're done. That's the way I've always done it. No problems.

[VA//M3]

Now that you mention it Spencer I do re-call seeing something along the lines of a coolant warning line in the KMB .TRC file.

[spencers]

Now that you mention it Spencer I do re-call seeing something along the lines of a coolant warning line in the KMB .TRC file.

Good deal! Maybe we can work with TerraPhantm to get it set up.
I haven't had enough time to dig around yet.

[MasterC17]

Has anyone been able to confirm that this exists in NCS Expert?

[nk_zhp]

Has anyone been able to confirm that this exists in NCS Expert?

I don't know about the NCS expert, but I personally have 2 concerns with this solution. One, it is probably tied to the same line as the red light on the coolant gauge, which I think is a little too late. And two, will require some monkey business with the ECU, which might be ok by a few members here, but it's not a solution most E46 owners would be comfortable with (plus is the software actually free? I know it can be had for free).

I am making good progress on this effort. Hoping to have something working in about 3 weeks.

[MasterC17]

I don't know about the NCS expert, but I personally have 2 concerns with this solution. One, it is probably tied to the same line as the red light on the coolant gauge, which I think is a little too late. And two, will require some monkey business with the ECU, which might be ok by a few members here, but it's not a solution most E46 owners would be comfortable with (plus is the software actually free? I know it can be had for free).

I am making good progress on this effort. Hoping to have something working in about 3 weeks.

:applause2:wub

[VA//M3]

I don't know about the NCS expert, but I personally have 2 concerns with this solution. One, it is probably tied to the same line as the red light on the coolant gauge, which I think is a little too late. And two, will require some monkey business with the ECU, which might be ok by a few members here, but it's not a solution most E46 owners would be comfortable with (plus is the software actually free? I know it can be had for free).

I am making good progress on this effort. Hoping to have something working in about 3 weeks.

Yes, it is absolutely free.

http://forums.bimmerforums.com/forum/showpost.php?p=19702306&postcount=1481

In addition I've attached the output given by a couple of the modules below when performing a read operation out of my car. With the help of google translate or NCSDummy you can make out more or less what each one of the settings alter.

I could also upload all the files up into the server where the forum is hosted and only make it available to certain users so no one abuses it and cause the server to exceed its alloted bandwidth.

The e46-KMB Moduleparameters file lists all the possible settings for each function within the instrument cluster.

If you notice my KMB is coded with

AKUSTIK_GURT_WARN Acustic_seatbelt_warning
nicht_aktiv

On your car it would be set to aktiv.

Also on my LSZ

TAGFAHRLICHT
nicht_aktiv

Which turns of DRL's.

Those are pretty much the only settings I've changed on my car on those two modules.

I'll list a few other mods you can perform on the Instrument cluster

AUSSENTEMP_WARN_AKUSTIK
aktiv

set it to nicht_aktiv to get rid of the outside temperature cold temp warning

RDKS
nicht_aktiv

Set it to aktiv if you were to retrofit a TPMS module

Also some people say our speedometers read about 5% higher then they should

BC_V_KORREKTUR
aktiv

setting that setting to nicht_aktiv has been found to correct that. More info http://forums.bimmerforums.com/forum/archive/index.php/t-1558931.html


As you can see it's extremely easy!

The hardest part is getting the hardware and software together.

[nk_zhp]

The only references to the coolant temp I see in those files are

KUEHLMITTELTEMP_ANZEIGEWI (coolant temp display)
kennlinie_01


and

KUEHLMITTELNIV_FILTERZEIT (something about filter time)
wert_01

[VA//M3]

Any idea what the ruecker part means?

RUECKWAERTSGANG_WARN_MED
piezo
RUECKWAERTSGANG_WARNUNG
nicht_aktiv

EDIT: it stands for reverse gear warning.

[nk_zhp]

LOL, does this mean I can make the car sounds like a truck backing up? :)


Any idea what the ruecker part means?

RUECKWAERTSGANG_WARN_MED
piezo
RUECKWAERTSGANG_WARNUNG
nicht_aktiv

EDIT: it stands for reverse gear warning.

[VA//M3]

What about

TEMP_SCHWELLE_WARMLAUF
wert_01

Which stands for temp Threshold running hot.

and

TEMP_SCHWELLE_BETRIEB
wert_01

which stands for temp threshold operation

Unfortunately, there is only one option you can pick. To lowel the threshold It would have to be modified by modifying that specific function in binary to manually go off at lets say 102 C'

Further info can be found here

http://forums.bimmerforums.com/forum/showthread.php?t=1483234

Not sure if it is possible at this point. Without modifying some of the files NCS expert uses to code to the instrument cluster. I may be wrong though.

[VA//M3]

Lol, I have no idea I haven't tried it out.

[nk_zhp]

I the last 2 weeks I've been learning a lot about the coolant temp management on my car. There are couple of things DME does that I found to be interesting.

1st one, is that once a specific temp is reached, the needle is moved into the middle of the red zone. It's no longer showing a temp, it's simply a way to say "I am hot!". That Threshold you just mentioned might be the temp at which this is triggered. So Wert_01 (value 1) might be highest by default (or lower, I dunno).

Secondly the gauge has a built-in heat soak detection mechanism. When the engine is shut off and the coolant temp is rising as a result of the hotter components still propagating heat into the coolant (but it's not circulating), when you turn the key and the temp is above normal, the gauges will not move higher than the mid point to not alarm the driver without cause. If after you started the car, the car does not cool off, the gauge will eventually act. I wonder if the second setting, controls how "patient" this mode is.

[nk_zhp]

Hi gang, please meet project CoolantSnitch.

http://www.youtube.com/watch?feature=player_popout&v=OvyPOr5aNHA

Part I - prototype design utilizes BMW coolant sensor p/n 13621433076

Stay tuned for Part II where we will be testing the device attached to the sensor in the car.

Hopefully working test units will be available in a few weeks.

[danewilson77]

Nice.........in for results and possible purchase.

[MasterC17]

Hi gang, please meet project CoolantSnitch.

http://www.youtube.com/watch?feature=player_popout&v=OvyPOr5aNHA

Part I - prototype design utilizes BMW coolant sensor p/n 13621433076

Stay tuned for Part II where we will be testing the device attached to the sensor in the car.

Hopefully working test units will be available in a few weeks.

:jawdrop This is awesome, can't believe you got it to work with the factory sensor. I would definitely pay money for this! Incredible work, thank you.

[BCS_ZHP]

Got this tip from a long term BMW mechanic. He said open the expansion tank and look at the fluid level indicator, i.e, thermometer. If its dark red, you coolant system is normal, that's the color its supposed to be. If its a lighter red, start investigating/replacing parts in your cooling system. And if its pink, failure is immenient, replace the expansion tank, radiator, and thermostat at a minimum. Last note, he said you shouldn't see pink until 100K miles or more.

[danewilson77]

Question? Is the float material specificlly designed to change color? Really? Or is this just a *trick o the trade"?

Droid! Srs Legitness!

[BCS_ZHP]

Trick of the trade, this guy is/was a 40 year BMW mechanic.

[danewilson77]

Copy.

Droid! Srs Legitness!

[nk_zhp]

Hi all,

Here's Part II of project CoolantSnitch. In this episode the circuitry is connected DIRECTLY to the coolant temperature sensor in the cylinder head. The device has very high impedance which makes it "invisible" to the rest of the subsystems (DME or the sensor). The triggering temperature here is set to a normal range so that the car does not need to be overheated to demonstrate how it works.

At this point I will be finalizing the components and setting the triggering level at roughly 118C and document Part III in which the car is overheated above operating temperatures (in a controlled manner... not for the faint of heart).

I think the device can be had for under 100 bucks. It might be less, but at times it's hard to predict these things until all components are gathered together.

Any thoughts are much appreciated.

Sorry for slightly dark lighting in the video.

Enjoy:


http://www.youtube.com/watch?v=CpxDzlaPbuo

[kayger12]

Very excited about this.

I will certainly be among your first sales.

Continued good luck with the project.

Droid X. Tapatalk. Use it.

[MasterC17]

Excellent, I presume now you just have to create a 'box' or something to hold all the circuitry? Great work, I'm very excited about this.

[nk_zhp]

Master and Kayger, thanks for your enthusiasm, it helps!

Yes, the goal is to have it assembled on a proper circuit board with an enclosure sized about half of an iPhone. The buzzer will need to be routed into the cabin. Working on those details now.

[danewilson77]

Well done nk............

In for sales!

Droid + Tapatalk = FTW!

[nk_zhp]

1st prototype on a printed circuit board. Hoping to start testing its real world performance very soon. Will be enclosed in the box pictured, about 1.5 inch square.

http://www.zhpmafia.com/forums/attachment.php?attachmentid=872

[Johnmadd]

Wow, you are really smart.

[kayger12]

1st prototype on a printed circuit board. Hoping to start testing its real world performance very soon. Will be enclosed in the box pictured, about 1.5 inch square.

http://www.zhpmafia.com/forums/attachment.php?attachmentid=872

Great job nk! Impressive progress.

Droid X. Tapatalk. Use it.

[nk_zhp]

Thanks guys, it's been moving a bit slower than I'd like since I am in a midst of a "gut-to-the-studs" kitchen remodel...

...holly smokes I'll tell you..

[nk_zhp]

IT'S ALIVE!!!

This is the final installment of the series showing the device in action. In the vedeo below the device is essentially in it's production ready form. It is not wired in completely however I finished that part later on and it came out pretty nice. Basically the routing is as follows. 3 T-tap connectors are installed in the ECU box. #1 - T-tap to the coolant temp sensor line, brown/red wire in the 52PIN connector going into the ECU. #2 - T-tap into the switched power supply line into the ECU, this line is properly fused for the ECU. #3 - Ground wire going into the ECU. The speaker output from the device is then fished out into the cabin by the driver side knee bolster. There is a nice opening from the ECU box into the cabin that is perfect for this routing. The buzzer is secured to the bolster from the inside using strong double sided tape and then it's connected to the wire coming from the ECU box.

The device picks up temperatures over ~117C degrees (see the coolant temp output on the OBC, by the ambient temperature readout). This is approximately at the last notch mark on the temp gauge before the "red" zone. There is plenty of time to pull the car over safely. The buzzer will remain on until the temperature drops below the mark. In the video below, the radiator fan wiring is disconnected which leads to intentional overheating of the car.

I am planning on running the device on my car for the next few weeks to make sure it functions properly, additionally I may install one on a friend's car. This device will work on MS45.X DME's. These DME's came with all E46s produced after 3/03. All ZHPs should fall into this category. I will need to perform additional testing to validate the device for MS43 DME's that are found on pre 3/03 E46s (330 and 325 models).

If we can get ~10 people interested in the device, I think it can be had for ~$85 shipped.


http://www.youtube.com/watch?v=mn6nYTNCuGI

[danewilson77]

Time 2:46. Looking good. What is the set temp and reset temp?

[nk_zhp]

Time 2:46. Looking good. What is the set temp and reset temp?

The triggering temp is ~117C +/- half degrees. anything over the device is on, anything under it's off.

[danewilson77]

ok.....and normal op temp is.....?

Sorry...I know it's in this thread somewhere......

[nk_zhp]

Normal operating temps are generally under 100C. BMW on this car however utilized so called characteristic map temperature control. In short unlike conventional thermostats the DME can modify the thermostat opening temperature by ~20-30 degrees. Under certain circumstances it will allows the engine reach as high as 113C. To be honest I have never witnessed temps this high. The underlying reason being better fuel efficiency under partial load at temps this high. Anything over 113 BMW considers above normal, in fact this is when the needle starts to move upward (you'll notice in the video). At 120ish the needle is at the 3/4 mark and at some point it moves into the red, I don;t know the exact temp mark for this.... and I don't want to know :)

[danewilson77]

So...117 allows full op temp....but early enough warning to prevent damage. I like the design characteristics.

[nk_zhp]

Let me throw another piece into the mix. There is a phenomenon known as heat soak. If you run your engine under heavy load for a long time (say track). As the engine is running the coolant is rotating through the system and cooling the block off. The core of the block is actually way hotter than the coolant temp. When you shut your engine off without a prolonged cooldown, the coolant temp starts to rise. This is because the core of the block is still propagating heat outwards but the coolant isn't circulating through the system and is heating up. By adding a few degrees to the top of the possible operating range we can ensure that this condition does not create a false alarm. In fact BMW's gauge is smart to detect this condition and will not move for the 1st few seconds after restart to not get the driver to panic.

Another piece of info worth adding, the CoolantSnitch has a small switch inside that can be set to 2 positions, all that does is change the triggering temperature. Position 1 is set at 117, Position 2 is set to ~75 degrees. This is done to allow you to test the device and make sure it's properly function before it's switched back into the "defcon" mode.

[danewilson77]

^Like

[MasterC17]

:applause Awesome work, let me know when I can buy one :fistpump

[danewilson77]

:applause Awesome work, let me know when I can buy one :fistpump

+1

[nk_zhp]

Shooting for end of May for 1st 10 units. Master I can bring it to our next auto-X, maybe we can even install it on the spot. Takes all of 20 minutes.

I took the car for ride today with the unit installed, so far no fires and no unusual warning lights... wife still thinks I drive too fast, so in short everything is A OK :).

Will keep you guys posted.

[MasterC17]

Shooting for end of May for 1st 10 units. Master I can bring it to our next auto-X, maybe we can even install it on the spot. Takes all of 20 minutes.

Nevermind - my graduation is the date of the next autocross so I can not attend :(

[WOLFN8TR]

Bump...

http://zhpregistry.net/Tech/CoolantSnitch.aspx

[Pilot05]

Adding a coolant temp switch & horn/buzzer to block drain plug as an early overheat warning ?

Sorry to revive an old thread, But can I please ask you folks about this? I have teenage drivers who are not going to watch the temp gauge like I do. They don't understand how a BMW engine can be junk after 60 seconds in the red

I know how to change the temp gauge buffering using PAsoft. But I want to add an audible alarm to both my ZHP and my E39

My plan is to wire up a simple 12V horn/ buzzer in glove box or engine bay (louder) and have it triggered by this temp switch which is threaded into the block drain plug:

http://a.co/9GIdL0s

This switch is threaded M14 x1.5 (matching my e39's block drain plug) and triggers at 110c which is generally (almost always from what I can tell) above the BMW 6 cyl operating temps. I understand the Block Drain may not be an ideal place to measure coolant temp as it's on the cool side of the block, but I think that is okay. I am a little concerned that this switch is a bit longer than the drain plug.

Similar thread here from a guy with his Z4 M coupe:
http://www.bimmerfest.com/forums/showthread.php?t=190021

Thoughts?

[WOLFN8TR]

Sounds like you need an UltraGauge. You can can set alarms for just about everything. I have a temp alarm set at 210 degrees so when my wife drives my car she will know when it's getting hot. The UG can check and clear engine trouble codes as well. The screen is blue but using some film (R25) it will match the BMW dash lights.

http://www.ultra-gauge.com/ultragauge/

https://uploads.tapatalk-cdn.com/20170405/6f447ef77006a49ff9bb60b6bc798020.jpg

[az3579]

Adding a coolant temp switch & horn/buzzer to block drain plug as an early overheat warning ?

Sorry to revive an old thread, But can I please ask you folks about this? I have teenage drivers who are not going to watch the temp gauge like I do. They don't understand how a BMW engine can be junk after 60 seconds in the red

I know how to change the temp gauge buffering using PAsoft. But I want to add an audible alarm to both my ZHP and my E39

My plan is to wire up a simple 12V horn/ buzzer in glove box or engine bay (louder) and have it triggered by this temp switch which is threaded into the block drain plug:

http://a.co/9GIdL0s

This switch is threaded M14 x1.5 (matching my e39's block drain plug) and triggers at 110c which is generally (almost always from what I can tell) above the BMW 6 cyl operating temps. I understand the Block Drain may not be an ideal place to measure coolant temp as it's on the cool side of the block, but I think that is okay. I am a little concerned that this switch is a bit longer than the drain plug.

Similar thread here from a guy with his Z4 M coupe:
http://www.bimmerfest.com/forums/showthread.php?t=190021

Thoughts?

Since you asked for thoughts:

I may be old fashioned with this thinking, but I'm of the "train 'em" mentality. They need to know the importance of paying attention to the car's gauges. If the car overheats and gets damaged due to their negligence, "you break it you buy it". That'll make sure they pay attention...

Since you already have the coolant temp gauge coded to something a lot more conservative, that glowing red light in the hot zone needs to be more than enough to grab their attention (while still being in the safe zone). I would image the car beeping when it gets there, but I've never ran it that far so I wouldn't know for sure.

But that's just me. That is what gauges are for.

[cakM3]

Sounds like you need an UltraGauge. You can can set alarms for just about everything. I have a temp alarm set at 210 degrees so when my wife drives my car she will know when it's getting hot. The UG can check and clear engine trouble codes as well. The screen is blue but using some film (R25) it will match the BMW dash lights.

http://www.ultra-gauge.com/ultragauge/

https://uploads.tapatalk-cdn.com/20170405/6f447ef77006a49ff9bb60b6bc798020.jpg

+1



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