jimfed

My car seams to be leaking anti freeze but I can't seem to find where the leak is. The hoses are dry, the water pump is also dry. I did find some anti freeze on the drivers side rear of the engine block. I removed the scatter shield and it is perfectly dry and no issues there. Could I possibly have a head gasket leak and if so what are my option. The engine is original with 12K original miles with aluminum heads.

don hall

What is the year of your vette?
12K miles?

See if this info helps:

http://www.benplace.com/pressure_test.htm

c4cruiser

His avatar shows what appears to be a yellow '86 Indy Pace Car (door decals).

A head gasket leak is a possibility. By "scatter shield" do you mean the inspection cover at the bottom of the auto trans bellhousing? Coolant in there could point to a leaky freeze plug at the back of the block. Did you look at the block freeze plugs below the cylinder head?

You might want to get a cooling system pressure tester (AutoZone will have them for rent) and put something like 16-20 psi of pressure in the system. Then look for any leaks.

hcbph

Pressurize the cooling system and listen and look for the leaks. I had a leak that turned out to be the hose that goes between the TPI and block behind the waterpump. I did find one thing that might help. Quite by accident after fixing that leak I was using a black light to see if I could see anything on a AC freon leak (looking for the dye). It showed the remnants of the coolant leak (didn't expect that). I don't know if you can rent them, but you can get a cheap battery black light flashlight off ebay for $3-$4.

Hope that helps.

jimfed

The car is a 1986 Corvette pace car !

jimfed

Yes I took off the inspection cover off !

jimfed

Will try the pressure tester. I just spoke to a friend who owns a shop and should be able to test it for me.

jts90vette

Intake manifold gaskets are known to leak coolant on L98's.

C4boy

If the leak is near the driver's side rear of the engine block, I would check the following: Inspect the area where the head meets the block at #7 cylinder. If you have the optional engine oil cooler (KC4, I think), check the hoses going from the cooler to the metal cooling pipes and all around the oil filter. A pressure tester may help expose the leak, but if you have a working radiator cap, it probably won't make a difference. Drive the car til it's warm then park it over some cardboard.

jimfed

I haven't checked that yet but when I first bought the car 29 years ago I now remember I had that problem and GM fixed it for free under warranty !

jimfed

I don't have the optional engine cooler on my car. I plan on running it again while it's on my lift tomorrow and see if I can spot it with a bright flash light. My friend is going to perform a pressure test on it when I can get the car to his shop !

LongBeachC4

My 85 had the same problem and I could not find the leak. Well the water pump let go and I thought that was it. Turned out it was the water pump gasket driver side. You might also look at the heater valve on the passenger side, I had too fix that back a couple of years ago.

seu318

I had a very slight coolant leak on my 91. I could not see anything obvious until I took a flashlight and one of those extendable mirrors and had a look around. I found the underside of the throttle body coolant bypass hose was wet and leaking. You might check that as a possibility.

MrWillys

GM used a steel manifold gasket with aluminum heads and manifolds in those years. It creates and electrolysis at the water jacket ports. Could be any of the other comments above but I've had this happen to me. Make sure and replace with FelPro blue should this be the problem.