Black Flaky Tar in Coolant

[BavarianZHP]

I checked my coolant level today (had to add 400 ml :blink) and noticed that there were black, flaky tar-like substances clinging to the level indicator (the flat, white platform of the indicator). It's like speckles of dirt covering most of the platform... It seems like engine tar, but there's no discoloration of the coolant. I'm worried it could be the head gasket. :crying

Anyone have this issue or know about it?

[danewilson77]

Ugh. How is the car running?

Sent from Williamsburg, VA USA

[BavarianZHP]

Car runs fine, and has been without any hiccups of any kind. Temp has never gone above the half-way point, although it's winter now so overheating shouldn't be a problem. I just bought this thing and didn't notice it until now.

[BavarianZHP]

Oil level has stayed at full ever since I've owned it (just about 2 wks now).

[danewilson77]

If oil looks fine.... I would say conservatively speaking you could have it tested. You could also have a coolant flush performed and start fresh. There may just have been some foreign material introduced into the coolant system at some point.

Has coolant overhaul been performed? Could it be some broken down oring material?

Sent from Williamsburg, VA USA

[BCS_ZHP]

Check the rubber seal on your expansion tank cap, that's a known weak point and the rubber there will deteriorate due to thermal cycling and let vapor seep by. Open the cap when the engine is cold, rub your fingers roughly around the cap seal and see if it flakes off into your hand. So your coolant loss and the tar(rubber) substance may be this cap telling ou it's time for replacement. These caps are such a weak point, in my opinion, and they're less than $10, that I normally keep a spare one in the cabinet in my garage.

[BavarianZHP]

Oil looks fine - no milky residue, haven't checked the exhaust color while revving the engine though. I guess it could also be the hoses corroding? Whatever it is, it's a bad sign - probably HG failure?

[BavarianZHP]

Not the cap, Just cleaned it. I wish it was...

[BCS_ZHP]

And if it is the cap, you likely will see some white residue evidence on the expansion tank around the neck of the opening where the cap attaches.

[BCS_ZHP]

Your fluid level stick, what color is it, should be dark blood red. If its pink or even white, then time for a cooling system overhaul.

[BavarianZHP]

^^^ Indicator is white... Time for that overhaul!

[BavarianZHP]

Yep, there was also white residue that I had to clean out around the lip of the cap.

[BCS_ZHP]

Okay, your black substance may be the seal from the water pump. Once it starts to go, the water pump impeller can wobble a bit on its shaft which further deteriorates it. It's logical that particles from that eroded seal would collect in your expansion tank. I believe your problem is the cooling system, not your head gasket, at least that's what I'd start with. I suspect when you do get the water pump off, the shaft will flop around and you'll be amazed that it was still functioning while being that loose. There's a weep hole on the bottom of the water pump that starts to leak when this seal goes bad, so that why you had to add almost half a liter today. ECSTuning had a cooling system overhaul kit, at a minimum do the hoses, water pump, thermostat, heat sensor and cooling tank. If you're over 100k miles, add a radiator too. Replacing tensioners and pulleys too since you're in there, is a judgement call based on mileage.

[BavarianZHP]

Here's the pic:

http://i218.photobucket.com/albums/cc12/Bike_enthusiast/BMW%20ZHP/DSC06142_zps2857c18e.jpg

[BavarianZHP]

Thanks for the input all, I'd be lost without you. The car just has 65k miles, no water cooling system overhaul - and I was expecting I would have to do it soon. Hopefully that's my problem.

[BCS_ZHP]

Okay, the bobber at the bottom is supposed to be white but the "thermometer stick is supposed to be dark blood red. A BMW tech told me that is the telltale sign of an impeding cooling system failure, normally the expansion tank goes first, then the water pump or thermostat. The white residue around the neck tells me your cap is going bad, the rubber may look okay but it's letting vapor seep by when the coolant is hot.

A cooling system over haul is a DIY, about $500 in parts and 4-5 hours to complete. There's a great DIY set of instructions on here somewhere, I set my iPad on top of the engine and followed the step by step photos to do my first one. Do you have a manual or automatic, there awesome special wrenches required for an automatic?

[BCS_ZHP]

#are some, not awesome

[BavarianZHP]

Ouch, $500 just after I blew my money on presents! :'(

It's a manual.

[BavarianZHP]

Found the parts list (see link). the DIY is great. I've looked at it before.

http://www.zhpmafia.com/forums/showthread.php?6129-Cooling-System-Overhaul-Price-Breakdown&highlight=cooling+system+overhaul

[danewilson77]

Ouch, $500 just after I blew my money on presents! :'(

It's a manual.

You can get level II kit for 3 and change. Also use BMW blue coolant. Looks like you got green in there now.

Prestone?

Sent from Williamsburg, VA USA

[BCS_ZHP]

Okay,I don't need to send you the fan removal tools required for an automatic. $500 was a full tilt job, here's what you need at the minimum:
- expansion tank, $65
- cap, $10
- water pump, $100,
- thermostat & housing, $40
- both radiator hoses, $60
- coolant temp sensor, $25
- one gallon of coolant, $20

You have to remove your belts, so if they're bad add another $40-50. And you're right there with everything torn apart, the new radiator is $100-125.

[danewilson77]

If he's trying to save money he could skip the temp sensor and just replace oring.

Add a gallon of DI water to the list though.

Additionally if we're pretty positive it's the water pump, you could just replace that, and the coolant and be done with it for a bit. Then in a couple of months perform the rest of the overhaul... But you'll be out the money you just spent on the coolant.

Moving this to to mechanical troubleshooting.

Sent from Williamsburg, VA USA

[BavarianZHP]

Unfortunately I used Prestone. I was panicking when I was low on coolant (the stick was a good 3-4 inches below the opening) and the BMW dealership was closed today.

[danewilson77]

Unfortunately I used Prestone. I was panicking when I was low on coolant (the stick was a good 3-4 inches below the opening) and the BMW dealership was closed today.

No biggie. Just use the right stuff when you do overhaul.

Sent from Williamsburg, VA USA

[BCS_ZHP]

Dane, check our PM.

#merryxmasuoldfekker

[BavarianZHP]

Thought adding prestone (50/50) was better than water or nothing. Personally, I really think it doesn't matter - not trying to start a war or anything.

[BavarianZHP]

No biggie. Just use the right stuff when you do overhaul.

Sent from Williamsburg, VA USA

Yep. Roger that. BMW blue it is.

[danewilson77]

Thought adding prestone (50/50) was better than water or nothing. Personally, I really think it doesn't matter - not trying to start a war or anything.

Probably isn't a big deal. But that doesn't look like a top up to me. It looks totally bright green. He should know to use the right stuff is all.

Is the pic right after top up?

Sent from Williamsburg, VA USA

[BavarianZHP]

Yep, pic was taken just after top off.

[danewilson77]

Yep, pic was taken just after top off.

Ok. Sounds good. Hopefully this is solved.

Sent from Williamsburg, VA USA

[BavarianZHP]

I'll replace everything but the radiator and perhaps pulleys... I've got a good excuse to do everything now.

[danewilson77]

I'll replace everything but the radiator and perhaps pulleys... I've got a good excuse to do everything now.

Perfect.

Sent from Williamsburg, VA USA

[BavarianZHP]

One last question:

OEM or just go for the aftermarket parts? There's a significant price difference:

OEM:
http://www.ecstuning.com/BMW-E46-330i-M54_3.0L/Engine/Cooling/ES263517/

Aftermarket:
http://www.ecstuning.com/BMW-E46-330i-M54_3.0L/Engine/Cooling/ES2063861/

[danewilson77]

I think aftermarket is fine. I have that second kit on my car now, with a Behr radiator.

Sent from Williamsburg, VA USA

[BavarianZHP]

Hmmm. I noticed that my "low coolant" light indicator didn't come on - I guess there may be some sort of failure there as well. I need to get a code reader! haha.

[danewilson77]

Code reader isn't going to help you with that.

[Hermes]

I may have a reman WP available soon (aka once I get around to installing my Stewart), less than 5k miles on it



Thought adding prestone (50/50) was better than water or nothing. Personally, I really think it doesn't matter - not trying to start a war or anything.

It does... unless you are adding the same exact stuff, ALWAYS top off with pure distilled water. Water is what actually does the cooling, the "coolant" is only to adjust boiling/freezing (mainly freezing) temperatures

[BavarianZHP]

Code reader isn't going to help you with that.

Yep, I only meant in a general sense. I think I'm going to get everything pressure tested as well.

[danewilson77]

Yep, I only meant in a general sense. I think I'm going to get everything pressure tested as well.

Yeah... Def good to have if you're gonna start going down the diy trail.

Sent from Williamsburg, VA USA