Joshv8q

Greetings all, how much pressure would it take to blow a big hole in the plastic protion of a radiator for a 1986 5000S (a/t no turbo)? Assuming there is no defect in the radiator, a car overheating should blow the 17lb cap first, right? I'm having a warranty dispute over this. Thanks,
Josh

selfproclaimedv8buff

not sure but mine blew pretty easily from overheating @ 3/4 of temp gauge.

boxerfan

I'mm check the manual and get back to you.

boxerfan

cap should release at 17 to 21 psi. There is no indication of an emergency relief section on the radiator. I would argue that it makes no sense to build in such a relief section. It would be redundant based on the release of the cap. Further, I would strongly suspect that the hoses should also give way before the radiator. The rad is one of the more expensive parts and it makes no sense to have one expended when the pressure rises due to some unforseen circumstance.

Assuming you have oil in your motor there is no logical reson for this failure IMHO.

pureroundcircle

the cap should definatley go first, but caps could be defective. I'll assume you have a newish radiator since its a warranty dispute. As they get old they tend to crack or bust, But a new one should hold up and blow the cap or hoses first i'd think.

Joshv8q

Well, I agree that the cap and hoses should blow before the radiator. As a precaution, the mechanic stated in his invoice that he tested the cap at and found it to be functioning. Hmm, sounds like a faulty radiator to me.

boxerfan

Agreed. Pursue it. They should cover it no questions asked.

shortyq

I'd bet that someone didn't backfill the block on install. Is this a thermostat and radiator replacement? If so, the block needs to be backfilled or you get a massive air pressure block that can pop the radiator. BTST. The trick is to either use a radiator bleeder (cool dealer toy) or backfill the upper radiator hose into the head.

Also bad WP or bad Thermostat can cause this problem. Not sure what was done, but I never do a radiator without a thermostat.

HTH

Scott Justusson
QSHIPQ Performance Tuning

Joshv8q

The cooling system was quite full as we had been driving the car for a few months. The thermostat was replaced when the radiator was. There was a 1 year/12kmi warranty. This mechanic is a very slippery one and I don't think that he is being straight with me. He claims that the radiator blew open because of a faulty fan switch. But, I heard the fan running when my wife drove the leaking car home from a short drive uptown. Even with the big hole in the radiator, the temp guage wasn't past halfway. He also wasn't able to find my old switch. Hmmm.