P0118 and false over heating problems

[stephenkirsh]

A few weeks back I had a P0118 code, coolant temp sensor.

The other morning about 1/2 mile from home I looked down and saw my coolant temp was pegged all the way red. Not possible. It usually takes 3-5 miles to get up to temps in the morning. Restarted car and it went back to normal. No code today.


What I'm trying to understand is where this temp sensor is actually located. I've heard people say it's in the t stat, and others say it's a different sensor on the engine back by cylinder 6.

Googling hasn't really given much info. Any help?

[san]

The coolant sensor is located on the lower radiator hose on the passenger side


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[stephenkirsh]

The coolant sensor is located on the lower radiator hose on the passenger side


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I thought that was just the fan switch that triggers the fan. It does not report temps to the temp gauge.

[SaltyNC]

There are two identical sensors. One is near cyl 6 in the back of the engine on the driver's side and the other is up front near the oil filter housing. FCP Euro has an OEM part that looks identical to the BMW part for less than $12 each
https://www.fcpeuro.com/products/bmw-engine-coolant-temperature-sensor-13621433076

http://www.realoem.com/bmw/enUS/showparts?id=EV53-USA-01-2005-E46-BMW-330i&diagId=11_2169#13621433076
http://www.realoem.com/bmw/enUS/showparts?id=EV53-USA-01-2005-E46-BMW-330i&diagId=11_2201#13621433076


Salty

[san]

I thought that was just the fan switch that triggers the fan. It does not report temps to the temp gauge.

I’m fairly confident this is what I replaced on the lower hose

https://www.ecstuning.com/b-genuine-bmw-parts/temperature-sensor/13621433076/

Edit:

You are right, this is what I replaced-

https://www.ecstuning.com/b-genuine-bmw-parts/auxiliary-fan-switch/13621433077/


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[SaltyNC]

You might be interested in this:
https://www.youtube.com/watch?v=3WE7sb6L6OI

Salty

[Smolck]

The sensor you need to replace is under the intake manifold, right by intake port for #6 cylinder. Here is a pic of it with the manifold removed (see red circle, disregard my hand, I was showing my friend a starter I replaced). I dont think you can replace it without taking the intake manifold off. If you do, replace the two hard lines that are under there while you are at it!

I hope that helps.31806

Here is an expanded shot for reference. Note, this is an E60 530 (last year of the M54) but identical to the ZHP engine (minus the cams).

31807

[stephenkirsh]

Do I need to take anything else off besides the intake manifold and DISA?

[Smolck]

Throttle body, intake boots, fuel injectors and rail, and a bunch of vacuum lines. It isn't as hard as it looks. Don't forget the big 14 or 15mm bolt that holds it down on the drivers side (ask me how I know)

[stephenkirsh]

I've never messed with injectors or fuel rail. Anything special about those?

[SaltyNC]

I replaced my thermostat, today, and I took off the intake filter box to get a little more working room. While I had that off, I remembered your post here, and I took a look at that sensor. I think removing the intake is the way to go to replace the sensor even if it is more work. I tried to see how the guy in the video I posted could have accessed that sensor without removing the intake, and I'm sure it is possible, but it must be next to impossible, and I would worry about cross-threading the sensor doing it so blind.

Salty

[Smolck]

It's tedious because the injectors are held on by little wire clips, be careful not to loose them. Plenty of DIY vids out there. Not a bad idea to order 6 new clips and a fuel injector o-ring kit. Then you can be less careful removing everything.

Make sure to start your car and pull the #54 fuse and let it die on its own (will throw a CEL, clear when done) so the fuel pressure is released.

@saltync, I agree. It's probably "possible" to do with the intake on, but no way is it practical or even worth messing with. Especially when the intake comes off in an hour or two. As you said, if you cross thread it (head is aluminum, easy to do) it's game over.

Besides plenty of good preventative things you can do with it off. If you have the cash, I'd replace the starter too.

[stephenkirsh]

Do I need the $45 BMW sensor, or is a 3rd party enough?

[Smolck]

Ive learned the hard way, for sensors, its OE or expect it to fail within 6 months.

[stephenkirsh]

Fair enough.

Ok, so for the "while you're in there" items...

There's a hard coolant hose? Or two? Anything else?

[Smolck]

Fair enough.

Ok, so for the "while you're in there" items...

There's a hard coolant hose? Or two? Anything else?
There's two hard hoses, there are a couple other ones (check realoem). You could also do the knock sensors, but I've never seen them go bad. It's super easy to replace the VANOS oil feed line if yours leaks, and the CCV is a joke to replace with the manifold off. Beyond that, I can't think of anything.

[stephenkirsh]

CCV was done previously.
Never heard knock sensor issues either, but I'll look into them

Are these the 2 coolant lines:
https://www.ecstuning.com/b-genuine-bmw-parts/heater-inlet-pipe/11531705210/
https://www.ecstuning.com/b-genuine-bmw-parts/water-pipe/11537502525/

Also, is this a good time to redo the dipstick o-ring?

[Smolck]

Yep, those are the ones. I'd replace the hoses that they connect to as well. The dipstick needs to be unbolted and removed, so why not, I would.

[stephenkirsh]

I've located this hose as one that connects to one of the two under the manifold:
https://www.ecstuning.com/b-genuine-bmw-parts/return-hose/11531436410/

On RealOEM, I don't see any that connect to the heater inlet pipe. (This diagram: http://www.realoem.com/bmw/enUS/showparts?id=EV53-USA-03_2001_E46_BMW_330i&diagId=17_0215#11531705210)

[stephenkirsh]

I've located this hose as one that connects to one of the two under the manifold:
https://www.ecstuning.com/b-genuine-bmw-parts/return-hose/11531436410/

On RealOEM, I don't see any that connect to the heater inlet pipe. (This diagram: http://www.realoem.com/bmw/enUS/showparts?id=EV53-USA-03_2001_E46_BMW_330i&diagId=17_0215#11531705210)

Hmm.. it appears it connects to #5 in this diagram:
http://www.realoem.com/bmw/enUS/showparts?id=EV53-USA-08-2004-E46-BMW-330i&diagId=64_0890

But it's greyed out and doesn't show a part number...

[stephenkirsh]

bump?

[Smolck]

I just found that I have an unused, brand new heater hose #5 in your diagram. If you want it, I'll sell it for a couple bucks less than I bought it for, if not, I guess I'll install it this spring.

31846

31845

[stephenkirsh]

Once we factor in shipping, probably not worth it. But thank you!

[Smolck]

Once we factor in shipping, probably not worth it. But thank you!

Your call. It's just sitting around. I was thinking $25 shipped was about right. I think I paid like $40.

Here you go, this is where I bought mine.....

https://www.oembimmerparts.com/BMW-Expansion-Tank-Hose-OEM-p/64218376153e46.htm

[stephenkirsh]

Rein is $18:
https://www.ecstuning.com/b-rein-parts/return-hose/11531436410~ren/

[Smolck]

Rein is $18:
https://www.ecstuning.com/b-rein-parts/return-hose/11531436410~ren/

Different hose. There are 2. that is the one that goes to the expansion tank. The one I have and the other one you need goes to the heater core

[Sockethead]

When you have the manifold off, look at it carefully. There are a few unused vacuum taps that have rubber plugs on them. Check them for cracks/dry rotting

[stephenkirsh]

When you have the manifold off, look at it carefully. There are a few unused vacuum taps that have rubber plugs on them. Check them for cracks/dry rotting

Yea, oddly, I replaced them 4 years ago but I'll double check.

[stephenkirsh]

Different hose. There are 2. that is the one that goes to the expansion tank. The one I have and the other one you need goes to the heater core

ah, found it:
https://www.ecstuning.com/b-rein-parts/expansion-tank-hose/64218376153~ren/

$29 on ECS.