Overheated, crap.

[GOOBER]

So I just finished putting my car back together after the last mishap where the intermediate gear decided to eat itself. I was driving and noticed my temp gauge rising. I pulled over when I could and then steam was coming out of the engine bay because the hose on the rear of the cylinder head was not tight and was leaking coolant. Now I turned the car off immediately and opened the hood so it would cool off. Eventually when the steam began to dissipate I opened the resevoir cap. I didn't however turn the heat up like I've been told I should've. Now I'm wondering if everything I just did went to shit. It was steaming for about 5 minutes after which I added more coolant and tightened the hose. Due to some electrical issue (which I haven't entirely figured out yet - thinking a dead battery) I wasn't able to start it up again... but it did crank when I tried jumping it.

I'm especially pissed because I just did a headgasket and used an OE BMW gasket fortunately I have a spare victor reinz laying around . I think the next course of action should probably be a compression test. I'm worrying like hell here so I'm wondering if anyone will give me some peace of mind whose had experience with this.

[jlevie]

There's running hot (gage between 1/2 & 3/4) and there's overheating (needle in the red). In the first case there is likely no engine damage. In the second case there is a good chance that the head has warped and the gasket damaged.

If the damage was severe, it may show up on a compression test, but the more common case is slight damage that won't be revealed that was. The most common case is a leak of air into the cooling system. An extended (for several minutes) leak down test using 180psi while monitoring cooling system pressure with a sensitive gage will usually locate small leaks. Or you can full bleed the system, drive the car for a bit and re-bleed. Release of a significant amount of air then or on a subsequent bleed is evidence of a leak.

[Wh33lhop]

If you think you may have blown a head gasket, you might want to look into something like this: http://www.sjdiscounttools.com/lis75500.html Checks for presence of exhaust gases in your coolant, pretty much a surefire test. I hate second-guessing, especially something like this, so it'd definitely be worth the $25 to me.

[GOOBER]

I started it up today and it didn't feel like a loss of compression but I'm not doubting that I may have a warped head. I'm gonna try a leakdown test and report back.

[Sagaris]

After doing my timing belt+water pump I filled the car with coolant, started it up and went to grab the Bently manual "real quick". When I went outside to begin bleeding it (engine was still running) I opened the bleeder screw and lots of air/steam came out. I went to check the coolant gauge and it was pegged in the red. I of course freaked out, turned it off, and added more coolant. I was worried that I had just ruined the head gasket (185k miles on the engine btw) and regretted leaving sight of the temp gauge.

I got the system bled, went for a drive and ended up seeing the "low coolant" light pop on within a few minutes. :( bad sign.


No, not really. I just had to clean the coolant level sensor and ~3000 miles later everything is still excellent. I am honestly suprised that nothing was ruined.

[GOOBER]

After doing my timing belt+water pump I filled the car with coolant, started it up and went to grab the Bently manual "real quick". When I went outside to begin bleeding it (engine was still running) I opened the bleeder screw and lots of air/steam came out. I went to check the coolant gauge and it was pegged in the red. I of course freaked out, turned it off, and added more coolant. I was worried that I had just ruined the head gasket (185k miles on the engine btw) and regretted leaving sight of the temp gauge.

I got the system bled, went for a drive and ended up seeing the "low coolant" light pop on within a few minutes. :( bad sign.


No, not really. I just had to clean the coolant level sensor and ~3000 miles later everything is still excellent. I am honestly suprised that nothing was ruined.

Well that's reassuring. I'm hoping I'm in the same boat.