Head Gasket

number53alero · 08-06-2015, 05:17 PM

So the car overheated after about 5 minutes of driving on the way home just getting on the highway. As soon as I heard the bell I looked saw the temp maxed out and cut the engine off and coasted to the side of the highway. Recently I also noticed that it would run real rough for about 30 seconds if not driven for awhile (2+ days) but it would go away and so would the misfire code. I took it to the nearby Caddy dealer, who used to be Cadillac/Oldsmobile and they diagnosed it as a blown head gasket and wanted ~$2100 to repair it.

Is this something I can do on the side of the street or in a parking lot? I talked to one garage and they wouldn't touch it since it was overheated saying the engine isn't reliable any more, that the block could be warped. I need some opinions please. Is it best to do the head gaskets or just swap in a new engine?

03glgold · 08-06-2015, 06:01 PM

Being a final 500 I would try to keep it as original as possible.

AleroB888 · 08-06-2015, 06:27 PM

Blown head gasket doesn't sound right, what's the mileage? Any smoke out of the exhaust? Other things can cause overheating. Radiator, LIM gasket...

sleepyalero · 08-06-2015, 07:12 PM

You shouldnt have to swap an engine. If you pull the heads its ideal to take them to a machine shop to make sure the heads arent warped. If i remember right, the block is iron, the heads are aluminum. Best to have head work done when they are removed.

Moral of the story, cast iron is alot harder to warp then aluminum, i think the block is fine.

number53alero · 08-06-2015, 07:46 PM

It has 111k on it right now, no smoke out the exhaust that I've noticed, the coolant was a bit low in the reservoir, took about 2 cups worth to fill it. When it overheated and I let it cool down to below 3/4 line I was able to rev the engine in park a small amount and then it started cooling down and was fine. It seems to overheat when you start it from cold and then after it overheats and cools down it's OK to drive and stays at the 1/2 mark which is normal. It was that way twice which initially led me think thermostat or water pump. Thermostat was replaced 1.5 yrs ago and water replaced 7 years ago.

The dealer did an engine diagnostic and pressure test with cylinder leakage test. Said they found coolant on the spark plugs and in the oil.

AleroB888 · 08-06-2015, 08:22 PM

Years ago mine had some strange symptoms-- white smoke out the exhaust (coolant getting in the cylinders), misfiring, even a smell of fuel, and running badly. Everybody told me it had to be a head gasket, but I decided to replace the LIM gasket set with the Felpro metal version just to see what would happen. Luckily that fixed it for me, but that repair would be expensive at a dealership. I don't know if my car being boosted caused the LIM gasket to fail in a different way and cause those symptoms, but it suggests the LIM gasket failure is a possibility here.

Redog · 08-07-2015, 11:52 AM

I had a blown head gasket on the Redog, but I was lucky, I had compression gasses going into the water jacket, so if I floored it, the car would puke antifreeze all over the place. Ugh what a mess.

Drove the car like that for 7 months, while in the middle of a divorce and the ex had all my parts and tools. She did take the heads to the mech thou when my lawyer FINALLY got off his ass and sent her a letter saying she would be responsible for a new engine.

Cost me $1700 for the job

number53alero · 08-07-2015, 05:17 PM

Interestingly it drove 100% fine on the way to work and also on the way home from work. It didn't move above the 1/2 mark at all, even in slow traffic on the highway for 20 minutes in 80+ degree weather. If it gets bad again I'll probably attempt it in the parking lot of my Knights of Columbus council that I'm a member of.