Hey guys, I have a '95 VR Commodore, and am having problems with my radiator. It keeps running out of coolant, yet there appears to be no visible leak, nor any coolant on the ground. I took it to a mechanic and he said I need a new radiator, but I'm not so sure. Are there any steps I can take myself, to find out for certain if it's a new radiator I need, or if it's just another "you know what" trying to rip me off! BTW, I can roughly do about 100k's before it needs more coolant. Any help would be appreciated !
couple of things to check first. run the engine so that it's hot, THEN check for leaks. a leak will be easier to spot when the pressure builds up in the cooling system. If you still have no leaks, check how much water is in your coolant return tank, drivers side mounted on the shock absorber mound. if that's full, it might just need a new radiator cap. other than that, it could be a blown head gasket, which is worse than a new radiator. check for milky residue on bottom of radiator cap or oil filler cap.
Coolant leaks can be hard to find as hot coolant evaporates very quickly. It does however usually leave a powdery trace. If the mechanic says you need a new radiator then I'd imagine that he noted leaks from the radiator. I'd go back to him and ask to explain more.
try going around the engine and tightening all the hoses etc, including on the radiator. see if there are any bubles in the radiator whe nyou start the engine with the radiator cap off. is there a wet patch inside the car, normally in the passanger side foot well (this is normally evident if there is a leak in the heater core). try a new radiator cap also, there quiet cheap.
Thanks guys for all your help. I took it back to the mechanic and found out that it is indeed the radiator. A nice slow leak near the radiator cap on the radiator itself. I tried all the other suggestions as well, so thanks again.
