mixer

I noticed a leak(cooling Fluid) under my 90 vette.

I topped off the cooling fluid,started the car and let it get hot.
And I looked for a leak.. no leak

After 2 days of sitting cold.. the leak starts again.

What leaks on the cooling system when the car is cold but not hot?

Thanks for any input
Sam

corvetteronw

The usual way I learn how to fix my C4 is by f'n it up the first time and then doing it right after I figure out what I did wrong. So I don't claim to be very smart.
I read about this is a recent auto magazine. Looks like it might work for your situation:http://www.google.com/products/catal...d=0CLoBEPMCMAE

StealthLT4

Best advice I have is to clean everything very well then look for the leak. I had a leak from the plastic sides of my radiator, but it was the opposite of yours (leaked when really hot).

VetteMed

could be water pump, weeping from weep hole.

ch@0s

Rent a pressure test kit from you local auto parts store. Also test you radiator cap.Look a your coolant cap an pressurize the system to that spec. Now look for leaks and get back to us.

mixer

Thanks guys
Am I understanding this correctly?
If my coolant cap was faulty ,after a day or two coolant might leak out the waterpump weep hole?
Much like water stays in a drinking straw if your finger plugs the top opening.

VetteMed

no, that is incorrect. water pump weeps when its seals are going bad.

mickey5

'90s are notorius for weeping coolant at the intake manifold gasket in the rear corners. I've had mine doing this for 20 years...it dribbles a little on the floor every now and then. It's easier to wipe it up than replace the gaskets.

ch@0s

If you do a pressure test like I told you you should find your leak. Guessing is not going to get you anywhere. You should also check what everyone else is saying..water pump weep hole. hoses. clamps, intake, make sure its not coming out of the A/C drain hole..ETC
So is it coming from the weep hole?

ch@0s

Its just going to get worse and you will overheat and blow a gasket or worse.
GL with that.

trulytex

That is exactly what happened to my 1990 a few years ago. And I had heard at the time that this was a problem with 1990's. I had a blown head gasket at the #7 Cylinder (which is where this usually happens). Had to have the top-end of the motor rebuilt. I started a thread when this happened and included alot of pictures. I was loosing coolant and it got progressively worse until I started seeing steam come out of my exhaust. Here is a link to the thread.

http://forums.corvetteforum.com/c4-g...-cylinder.html

mickey5

I'm a little concerned, is this a manifold gasket or a head gasket problem or both? Having noticed this leak for so many years the coolant loss is usually the same, about 2 to 3 shot glasses a year. It pools in the niche between the manifold and the head at the back by #7.