Don't Let This Happen to You [engine cooling system: upper hose: bleeder screw]

[aurelius]

In the ongoing crusade to save our engines from their known cooling system failure points, I have the following story.

Driving along recently when I spotted an E46 getting the "helpful shove" of a police cruiser. It was a warm day and I immediately thought "M54 cooling failure." Turned around and found the guy and his dead 325 coupe in a parking lot. Not out of gas, he says. But he did have a leak at the plastic bleeder screw in the upper radiator hose that morning. He zip tied the screw to keep it in place, added some coolant and went to work. Fast forward to that afternoon. Says he drove for about 5 minutes with the temp needle in the danger zone, then the motor just quit. Popped hood, bleeder screw gone, engine devoid of coolant. 120k miles.

Luckily for him he has an extended warranty, which had already been called upon to clean up the mess of his cracked expansion tank some time ago.

Anyhow, when you replace your upper radiator hose, go nuts and spring for the $4 brass bleeder screw. [PelicanParts 17-11-1-712-788-M230]

http://i1125.photobucket.com/albums/l584/aurelius3/Random%20BMW%20Pics/plasticscrew.jpg
http://i1125.photobucket.com/albums/l584/aurelius3/Random%20BMW%20Pics/brassscrew.jpg

[kayger12]

Good info. Thanks!

[johnrando]

Good to know, thank you!

[danewilson77]

So......"under warranty", means you can be a complete jackwagon and melt your aluminum block, knowing you have a coolant system issue?

[aurelius]

Assuming his warranty is indeed still valid, he'll be getting a new (reman?) motor. All for the grand sum of $50 (deductible per service visit). Pretty sweet deal considering BMW's Certified Pre-Owned wouldn't cover any of the 6 things I brought mine in for just prior to CPO expiration. That was $50 down the toilet.

[danewilson77]

Damn....

[billschusteriv]

Good info. I was looking at this a while ago and thought to wait until overhaul.

Anyone else have experience using the brass bleeder screw on the plastic elbow? It may be common sense, but I've heard caution is necessary to not overtighten the brass bleeder screw?

[Whitexi]

I changed to the brass one when i did my cooling system at 130k. I never cared for a plastic bleeder lol.

[danewilson77]

I'm a purist. I will have none of this brass business in my engine bay.

[Whitexi]

Lol Its like a gold tooth in your cars mouth.

[danewilson77]

Lol Its like a gold tooth in your cars mouth.

Exactly. I will have nothing but oem stockness ensue on, in or around my whip...ahem...car.

[JohnnyGraphic]

I upgraded to the brass bleeder screw.

IIRC, there was another thread not too long ago about someone else who had a bleeder screw crack (not this guy).

Suppose the plastic won't be bad if you regularly change your tank/hoses/cooling system etc.

Johnny

[kayger12]

Exactly. I will have nothing but oem stockness ensue on, in or around my whip... except my wheels, bra, rack, AEs, suspension, strut bar, intake, and trim.
^^^
Fixed :innocent

[danewilson77]

^^^
Fixed :innocent

:rofl

[az3579]

Lol Its like a gold tooth in your cars mouth.

The kind of gold tooth you do actually want...

[billschusteriv]

I upgraded to the brass bleeder screw.

IIRC, there was another thread not too long ago about someone else who had a bleeder screw crack (not this guy).

Suppose the plastic won't be bad if you regularly change your tank/hoses/cooling system etc.

Johnny

Good point. Probably a good spare part to keep in the trunk/toolkit.

[spencers]

I've been using a brass screw since overhauling my cooling system last summer. The original bleeder screw is in the trunk with an extra expansion tank cap (just in case!)

My dad swears by them. :dunno

[billschusteriv]

I would just be careful not to overtorque the brass bleeder screw. I bet it would eat through the plastic threads on that elbow. Then you'd need to carry an elbow in the trunk too.

[danewilson77]

My plastic bleeder screw has 125,000 miles on it. I suppose you could get a million outta the brass one.

[llll1l1ll]

My bleeder screw is leaking right now. I'm afraid to drive my car. Since I need my car, though, I'll just hoof it up to the stealership (if they have one in stock) and pick it up rather than risk driving and having the irony of a failed bleeder screw on the way to pick up a bleeder screw.

When I install it, with the engine cold, will I need to re-bleed?

[danewilson77]

Most likely no....unless you lose coolant.

Sent from Williamsburg, VA USA

[llll1l1ll]

Looks like I lost a little bit of coolant, but nothing alarming.

[llll1l1ll]

Out of curiosity: is it possible that there was too much coolant in the system, and the excessive ambient temperatures in this heat wave plus lots of stop and go with the a/c on caused the coolant to expand so much that it bubbled out of the bleed screw?

I just thought of that a minute ago.

[danewilson77]

Out of curiosity: is it possible that there was too much coolant in the system, and the excessive ambient temperatures in this heat wave plus lots of stop and go with the a/c on caused the coolant to expand so much that it bubbled out of the bleed screw?

I just thought of that a minute ago.

Why do you think there was too much coolant in your car? What was the level before? Is there too much oil in your car?

Too much coolant can be detrimental, imho. That could have blown the o-ring. Did you inspect o-ring on bleed screw?

Sent from Williamsburg, VA USA

[llll1l1ll]

The coolant level was just a smidge above max. Not by much though. Like a half cm on the float - and that could have been because I was looking at the wrong angle. Oil level was fine - if not a little low (I fixed that on the oil change) - but it's still within spec.

HOWEVER, when I switched the bleed screw yesterday, I noticed the old screw did not have an o-ring and there was no o-ring anywhere to be found. I double-checked where the o-ring would sit when making the seal, and it was not there, either. The new screw had an oil ring. I ran the car for about eight minutes with the a/c on and everything and go it up to temperature. I have not noticed any leaks yet.

My guess right now is that either there was too much coolant and it bubbled out, or the lack of an o-ring caused the leak. The old screw did not appear to have any cracks upon a quick inspection. Perhaps the no o-ring situation was the cause.

[danewilson77]

There is supposed to be an o-ring, correct? Or am I thinking about drain plug?

Sent from Williamsburg, VA USA

[llll1l1ll]

No there's supposed to be an o-ring. My new one came with an o-ring. Plus it's two plastic pieces trying to seal a fluid in. There's gotta be some rubber in there to help.

[danewilson77]

OK....that's what I thought. I think you found the smoking gun (no o-ring/blown o-ring)

[llll1l1ll]

Same here.

Thanks for your insight!

[aurelius]

Also: if expansion tank cap is functioning correctly, excess pressure is normally relieved there.

[llll1l1ll]

Good to know - I didn't know that. I'll still keep my eye on it, but I think it was the bleed screw.

[danewilson77]

Also: if expansion tank cap is functioning correctly, excess pressure is normally relieved there.

It's a 2.0 bar system that's designed to see 1.0 bar.

Sent from Williamsburg, VA USA

[Hornung418]

G.a.s. is working on a 1 bar ET cap. Should be interesting.

Sent from Jefferson, NC.

[aurelius]

G.a.s. is working on a 1 bar ET cap. Should be interesting.

Discussed elsewhere on this forum recently but figured a link to product quoted above would be relevant HERE (http://www.germanautosolutions.com/bmw_solutions/cooling_system/index_cooling_sys_products.php).

[TigerTater]

SPAM


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[ELCID86]

Hmm interesting I guess. But we don't have that engine.


Thumbs, iPhone, Tapatalk.

[Hornung418]

Banned in 5....4...3..2.1

Sent from my GS3.

[danewilson77]

Damn....I knew I shouldn't let her in.

I took a gamble. ..and lost

Samsung Galaxy S5...

[WOLFN8TR]

I read that post last night and thought WTF?

[wsmeyer]

I was looking forward to the N62 ZHP DIY

[Avetiso]

I thought the N62 only came in the 2008 ZHPs?

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[gmurphy]

I thought the N62 only came in the 2008 ZHPs?

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No you have it wrong. It came in the 2009. :)


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