Cracked Cylinder or Blown Head Gasket?

It looks like either are the problem but I'm looking for some educated guesses before I pull the engine. Yesterday, I backed the car out of the driveway and allowed it to idle up to about 160 degrees and then shut it off. After doing some garage cleaning, I started it up and pulled into the garage to park before it started raining.

Shut it off and then noticed a sweet burning smell of coolant. I looked at the tailpipes and saw about four drops of fluid coming out, no biggee I thought because it was still cool outside so I wrote it off as exhaust condensation. The smell was unique though.

This afternoon, I had planned to go out for a cruise and went to start up the car. It wouldn't turn over. The starter would strike the flywheel but couldn't spin it. Now I'm getting anxious and starting to fear the absolute worst. Checked the oil on the dipstick and sure enough, it was just starting to go toward a shade of chocolate instead of black like normal AND my crankcase was now overfull and well past the full mark on the dipstick. Pulled the radiator cap and it's half empty of coolant. Uhhhg!! Start pulling spark plugs and it wound up being the #5 cylinder that was full of coolant - it just gushed out.

The last time I had taken the car out was last weekend and the temps have never been over 195 degrees since I've had this particular engine setup for 4 years.

With aluminum heads, I'd be VERY surprised if it was cracked so I'm leaning toward a blown head gasket.

What do you guys think?

It's either a gasket, a head, or the block. I'd pull the head and start praying.

I know that feeling, Wes. I felt it Wednesday when I tossed a rod in my 462 in the Firebird. Time to look for a 540. ;)

wes i feel your pain i just went through the same thing 2 weeks ago. I took the heads off and looked real good at the gaskets and only could see where one might have been leaking. and mine didnt make it to the cylinders that bad. good luck , my bets are on the gaskets these engines make alot of preasure .http://img444.imageshack.us/img444/1295/cars003tk7.th.jpg (http://img444.imageshack.us/my.php?image=cars003tk7.jpg)

Good luck Wes. Suspect head gasket. Hope nothing more. At least it's late in the year. Keep us posted.

This afternoon, I had planned to go out for a cruise and went to start up the car. It wouldn't turn over. The starter would strike the flywheel but couldn't spin it. Now I'm getting anxious and starting to fear the absolute worst.

How many times did you try to crank it? Since the engine was hydro locked you could have bent a connecting rod. Something to check.

Thanks guys for the feedback. You know, it must be a head gasket considering how it happened. I did beat on the car a bit last weekend when I had it out for a Sunday drive but the temps never got crazy at all. Ran perfectly fine with zero issues but that last drive could have been the head gasket's death nail.

I sure hope it didn't bend #5's rod. The only time it could have was when I pulled it back into the garage yesterday before the rain. It ran fine then too, but just started hard. :eek: I plan to start tearing into her over the holidays and then off to Owens Racing for a complete long-block rebuild.

Thanks for feeling my pain ya'll. I spent a couple of hours last night doing a quick wax for the entire car and now this. It's the first time my Chevelle has had a catostrophic engine failure in the 11+ years of ownership so I guess I shouldn't be too disappointed. Just sucks knowing she's all shiney and no place to go. :sad:

Just a couple of thoughts Wes. First thing, until you drive over the crank you haven't had a catastrophic failure. LOL Secondly you might want to consider detonation as a possible cause.
Mike

Wes,I bet there is coolant leaking past the valve seat and you hydrolocked the motor.
You probably now have a bent connecting rod

if your running boost, may have just pushed out a head gasket, esp if stock 502 and stock head gaskets-you can guess all day what it is, you have to pull it down

Head gasket. No reason to suspect anything else at this point.

Wes, hadn't seen you post in awhile, so I swallowed real hard when I read this one. Hope it's not too bad...:(

Hopefully a head gasket. Are the heads "O"-ringed & are you running some big boost? I hope for the best.....

Haven't torn her apart just yet but I think you guys are right in that it's probably a head gasket issue and nothing more. It sure did fill up the #5 cylinder with water quick though...that I was really surprised about.

The total timing is set at 34-35 degrees and I've been hitting it with only 7.5lbs of boost on 93 octane pump gas. Not much boost BUT I probably should have backed off the timing a couple of degrees. I had swapped pulley's last year to bump up the boost levels (used to be only 5lbs) but didn't back off the timing, so that could have caused the problem. The heads are not O-ringed and I cannot remember which type of head gasket we used four years ago.

Drained the oil pan yesterday and it had about 2-3 quarts of water in it. I'm pretty shocked at how fast all of that water got into the motor in such a short period of time. We're talking no more than 1 minute or two of idling in the driveway when I 'think' it happened.

Yea Dan, I don't see these parts very much anymore. I hope that you and everyone else here have been doing well. :)

sounds like head gasket to me too. if your going to increase the boost it might be time for some new cometics. mike