Mysterious coolant leak on the M3, any ideas???
- Thread starter Turk
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Essentially the head bolts/stud stretch a little and allow some portion of the head itself to flex/lift off of the block.
This is a HUGE Diesel problem (early Ford 6.0 Powerstrokes are known for it).
I have never heard of a case being severe enough to damage the chain/belt/tensioner/etc, but typically it breaks the seal of the head gasket and can wreck the bolts/studs.
I'd make sure to bleed the coolant system and check all your hoses. Hopefully its nothing like a lifted head...
Usually, no. Sometimes the combustion gasses can burn the head... but that requires a pretty long pull. That didn't happen here I'd be willing to bet, esp since it seems to be sealed up just fine now.
My heads were lifted on the TA last year. I unknowningly lost a ton of compression and boost... but it never leaked coolant that I saw. When I finally figured it out and replaced the head gaskets and torqued the heads tighter... the car really came alive. Enough boost and you'll lift heads, no doubt.
Didn't you have to mess around with hoses and the coolant system to install it? It could be something really simple. I highly doubt you damaged the head gasket.
Good to hear. Would be pretty hard to lift heads on only 6.5psi with a pretty low flow supercharger like you have.
OK, so here goes the rest of the story. I get off work today and take it to my friend that owns a shop. He's always been completely honest with me and doesn't blow any smoke up my ass. So I get it there, and we just look at it for a good while on the lift etc, and we can't figure it out still. We do the pressure test on the coolant system and everything checks out ok, not a single leak. So I say, how about I take it for a ride real quick and beat on it again, to try to replicate what had happened. So I take the car out, wait for it to get into operating temp range and hammer it, just like the night before from about 5k to 8400rpm in second gear. About 10 seconds later, the low coolant light goes off, so I pull into a church parking lot and AGAIN, coolant is everywhere, WTF IS GOING ON!?!?! So we open the hood and STILL can't find where the fuck the coolant is coming from, so I call the mechanic and he says, just bring it back, no big deal there's no coolant, just keep an eye on the temp gauge, since we are only about 1 mile from the shop. I'm able to get the car back to the shop, and we're all completely dumbfounded, nothing is making sense, except a blown head gasket is sounding more and more likely. So we fill it up with more water again, but this time using a hose, and low and behold, water starts pouring liberally from where where you connect the radiator to the block, FINALLY, we found where the leak is coming from. The hoses on the BMW aren't connected very solidly, and this particular tube is in tight spot now due to the supercharger bracket, so it makes sense that if anything was going to get loose, it would be this tube. It also makes sense that under full throttle the seal would break from the engine torquing away from tube, it's just very odd that last night it resealed all on it's own. I'm starting to think that maybe I need new engine mounts, or stronger ones to keep this thing in place. So we reconnect this tube tighter this time, I get back on the car and take another ride, this time I full throttle to redline on 3 different occassions, and not a single drop of fluid lost. We get back to the shop and do the chemical test on the water, and the test comes back blue, PERFECT, no combustion leak! I thank God (even though I'm not very religious) and take the car back home. As the car sits right now, it's got water instead of coolant, but we are flushing that out saturday and changing out the motor oil. Thanks for all your help guys, but some of you made it hard for me to sleep last night! =)
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