View Full Version : Head Gasket job

12-24-2009, 04:14 AM
Just finished a head gasket job on my '95 3.4L Firebird. Here's the story, I had the oil changed, used Castrol GTX 10w30, Lucas Oil Stabilizer, and a Fram filter. Two days later was the first time i drove it decent distance since the oil change (over 10 miles). I stopped at a red light, and when i pressed the gas, a puff of smoke came from the exhaust, and there was a cough sound from the engine, and the temp was going up, but not real fast. I pulled over in a McDonald's parking lot, thankfully i was hungry too, haha. I popped the hood, and the coolant was about 2 gallons low, and there was a strong smell of gas in the oil too. Never had the gas in the oil problem before. Well, got the head job finished, and the sick chicken is well again! But haven't changed the oil yet. Drove it for the first time tonight, and oil is now leaking from the rear main seal. Could that be cause by the oil be diluted with gas, and it's seeping past the seal? And could blowing a head gasket cause gas to mix with the oil like that? Hoping i don't have another issue. :confused:

12-24-2009, 10:08 AM
How many miles are on the car? To answer a couple of your questions. The gas in the oil is not the cause of a leaky rear main seal. Those just fail over time, and is probably just a coincidence it happened then (or you just hadn't noticed it yet). As far as gas in the oil, it can be caused by a few different things. Could be from the engine not getting up to temp with each of your driving cycles (do you drive the car for short periods of time alot?). It can also be caused by "blow by" with worn out piston rings (if your car is high mileage). Either way its not a good thing and i would definitely get that changed and keep an eye on it. It can cause the oil not to lubricate properly and lead to bearing failure.

12-24-2009, 03:41 PM
The engine has 210,000 miles, but I replaced the front main seal when i replaced the water pump, just because it was torn down to it. Figured i may as well slap a new one in while i had it to that point. And the block was rebuilt before i bought the car last year, almost 30,000 miles ago. The rings were tight and snug, with no gap, top of the pistons looked great, and the cylinder walls looked immaculate. Definitely hasn't been leaking before this, I have a clean concrete driveway, and would've noticed an oil spot easily. I'm changing my oil today just to get that bad oil out, and hope for the best. A friend of mine just told me that he had one rebuilt, and decided since it was new, that he was going to go with 0w30 synthetic oil from now on, but it started leaking right off the bat from, wouldn't ya know it, the rear main seal! haha. Well, he changed the oil to regular petroleum 10w30, and hasn't had any leaks in almost 70,000 miles. I'm just hoping for the easiest fix honestly. :-) Maybe the fuel diluted the oil enough that it's seeping past the seal. But if not, here I go droppin' the tranny!

12-24-2009, 05:50 PM
whoa whoa there. Before you go doin anything drastic with the rear main seal I would double check that the O ring at the distributor cap isn't leaking. Sometimes it will leak out of there and pool up at the back of the LIM and then seep down the back. If you cop a feel back to where i'm talking about it should be pretty apparent if thats where it's leaking.

12-28-2009, 02:59 PM
Found the culprit for the oil leak, and boy do i feel like a dumbass! Haha. Got the FelPro head gasket kit for the car, and there was one small piece of gasket missing where the lower intake meets the block. There were 2 seperate pieces of gasket to between the heads and lower intake, but don't ask me why it didn't register with me that there should be a gasket for the block and intake. Anyway, tore everything back down, and got it taken care to. No issues, just an idiotic mistake. Thanks for the advice tho guys. And gas is no longer mixing with the oil either. Changed the oil, and have a couple hundred miles since, and no fuel in the oil. The only thing that i can think of that could've cause it, is possibly when i blew the head gasket. It never done it before, and hasn't done it since. I'm gonna keep an eye, and nose, out for it on a regular basis tho.