Head Gasket Replacement or other causes of leak

[f18_builder]

Hey Fellas -

1996 LT1 with Vortech Supercharger

I noticed a tiny bit of oil on the garage floor the other day. The car needed an oil change, so I got it up on jacks; that was Saturday. There was a thin coating of fairly fresh oil on the oil pan, structure just in front of the oil pan, all over the back portion of the drivers side of the block, and some collecting on the transmission cover. I cleaned up all of the oil and changed that oil and filter. Today(two days later), I backed the vette out and there was significantly more oil on the floor. However, it was dark like used oil. I don't see any oil on the head. Of course, my big concern is that the head gasket is going. I just bought the car and it is supercharged. The installation looks very well done and the kit is a Vortech. My concern is that the guy paid a ton of money on this stuff, but didn't know how to adjust it, and blew the head gasket. The boost Retard was set to very low when I got the car.

My questions:

Should I suspect the head gasket? How would I check other than a compression check. The car runs great! The coalant and oil don't seem to be contaminated.

What are other possibilities? I have heard that synthetic oils like to leak. These can't be normal aging right.

THE BIG QUESTION, how much would this cost to have done at a dealership, or good shop? I have done a head gasket on an old Honda. I would be very hesitant to try it on the new baby. The Honda was also OHC, so I got away without dismantling rockers, springs, pushrods, etc.

If I did try it this winter, how complete are the service manual instructions?

I really don't want to tear into the head gasket unless I have to... any advice on what to check before settling on the head gasket as the cause would be appreciated.

Thanks in advance.

 

[kingman]

Leaks!!!!!!!!!!!!!

Hi

Wait for one of the pro's to answer your question, but what l've been told and read the LT1 leaks are common. l have a 96 with 45,000 miles and it's starting to leak very slowly.

My dealer said it is starting to leak in three places and that l should watch it. If and when l decide to fix it, it will cost approx $800.

Welcome to the world of vettes.

Alan

 

[Dave C. '04 Z06]

Normally a blown head gasket won't cause an oil leak. It usually makes for a coolant or cylinder pressure leak.

Now for some possible bad news:
If you've been on it fairly hard and it's leaking, it could mean the rings are going bad and you're pressurizing the crank case under boost, wich would cause the oil to blow out. One way you can sort of perform a test for this is to let the engine idle and remove the oi filler cap. Hold your hand over this cap. There should be no noticable air pressure coming out. If you feel a "puff, puff, puff" then that's the chug of death. If you do NOT feel the puffing, then your are probably okay there and then check your front seal or between the intake and the block where the leaks are common.

If you haven't been driving it, I'd check things like the oil return for the supercharger on the oil pan, your drain plug, the oil filter, etc... Make sure everything is tight and has a good seal.

Good luck

-Dave C.

 

[f18_builder]

Thanks for the ideas. I'll check the filler cap tonight.

I haven't driven it hard. I have gagged it a few times while giving people rides, but only for a couple of seconds. Enough to get the standard, "Oh sh*&" out of them. Even those aren't WOT runs.

I do see oil up to the head gasket. Could this still be oil coming out of the crankcase? Just seems like it would blow out of the oil pan seal. I'll take a closer look tonight.

 

[HallenTi]

F18 Builder... I see that your last post on this thread was 06-24-2003... what did your problem end up being? I have some oil that appears to be seeping out between the head the the block on the drivers side, and I too wondered if it was a cylinder head gasket, but wanted to get some more feedback before I tear into it, and I saw your post. Thanks, Tim

 

[G Winter]

Heads on a chevy small block don't leak oil. At least VERY rarely. Check to see that it isn't coming from the ends of the intake. Those are sealed with silicone sealer and that sometimes drys out. My 90 is leaking there now and I am about to replace the intake gaskets .

 

[f18_builder]

HallenTi, sorry it took me so long to reply. This is the best explaination I have heard for the oil leak I have. The leak actually got better, but still leaks a tiny bit.

Actually this explanation may have come from this forum. I heard that the engine assembly plant in 96 wasn't waiting the proper amount of time before placing the manifold on the block. This didn't allow the sealant on the front of the valley to create a proper seal, and a small leak develops. A leak from the valley should be no big deal. A little bit of a mess, but no big deal. You might try sealing it up some how. Personally, it isn't worth tearing into the motor that far.