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View Full Version : Head gasket leak.....


kizdan67
04-14-2011, 05:10 PM
I have a '96 Prostar 205 with the LT-1 Corvette motor. I have about 535 hours on it.

At the end of last summer, a leak was noticed at the back, left side of the motor. I called the local dealer, and they tell me that it is very unusual to have a head gasket leak. If one occurs, it is normally because the engine overheated, and the aluminum head warped. I can't say I ever overheated it (I did come close when my impeller was jamming up). It may have occurred when I allowed someone's mechanic to go over it without me watching over him, when I was looking to sell it. If it means anything, compression checked out fine on all cylinders, but the one where the leak is tested lowest, at 180. The rest were between 185 and 195.

Anyways, the dealer tells me it will cost $70 in parts, $400 to have the head tested and trued, and $833 for labor!

Anyone have any experience in this area? Any words of wisdom, and/or advice?

j.mccreight@hotmail.com
04-14-2011, 05:59 PM
sounds a bit high to me, to resurface a cyl head should cost no more than 150, and 800 for cyl head gasket is a bit steep. Are you mechanically inclined? You can do this job in a couple of hours and find a local race shop to true up the head if it is warped.

JimN
04-14-2011, 07:08 PM
I have a '96 Prostar 205 with the LT-1 Corvette motor. I have about 535 hours on it.

At the end of last summer, a leak was noticed at the back, left side of the motor. I called the local dealer, and they tell me that it is very unusual to have a head gasket leak. If one occurs, it is normally because the engine overheated, and the aluminum head warped. I can't say I ever overheated it (I did come close when my impeller was jamming up). It may have occurred when I allowed someone's mechanic to go over it without me watching over him, when I was looking to sell it. If it means anything, compression checked out fine on all cylinders, but the one where the leak is tested lowest, at 180. The rest were between 185 and 195.

Anyways, the dealer tells me it will cost $70 in parts, $400 to have the head tested and trued, and $833 for labor!

Anyone have any experience in this area? Any words of wisdom, and/or advice?

The labor sound high but did they describe 'Labor' in great detail? This will need removal of the intake manifold, head, gasket material and checking the head for warpage. If it's not warped, it can go back on but all of the fasteners should be replaced. Also, it needs a marine gasket, not the one for a car. Get more details and call around for prices on checking a head- that $400 seems very high but again, there aren't enough details to know for sure. If you really want a better idea, go to a speed shop and ask how much they would charge. It's possible that the marine shop doesn't do this kind of work often enough to really have a handle on how much it should cost and they just looked in their rate book.

Why do you think it has a gasket leak- the 5 pound drop in compression? That 180 number is well within the acceptable range. If it's the #8 cylinder, look on the intake manifold for the PCV tube- is it connected to the #8 intake runner, or at the base of the throttle body? If it's at the runner, it should be moved, although this is more likely with a TBI motor.

kizdan67
04-15-2011, 09:28 AM
Why do you think it has a gasket leak- the 5 pound drop in compression? That 180 number is well within the acceptable range. If it's the #8 cylinder, look on the intake manifold for the PCV tube- is it connected to the #8 intake runner, or at the base of the throttle body? If it's at the runner, it should be moved, although this is more likely with a TBI motor.

Because my step-son (who is a mechanic), spotted some oil in that area. I'll have him check for the PCV tube.

JimN
04-15-2011, 08:34 PM
Because my step-son (who is a mechanic), spotted some oil in that area. I'll have him check for the PCV tube.

I'd pull the valve cover and make sure it's not coming from a leaky gasket. It could be that the hold-down bolt O-rings have shrunk and are letting a little oil out at the bottom. The bolts should have a tapered shoulder above the thread and if not, you can get the kind that do but make sure the seat is tapered first. Be careful tightening these- they're really hard and brittle, so they snap easily.