1972 LS-5 issues

[D S.]

Radiator overheating issues and oil pressure gauge malfunction issues. The car was restored approximately 20 years ago but has been kept in excellent shape. It Top Flighted in 2006 in San Antonio.

1.) Can bad head gaskets cause overheating? It has a 195 degree thermostat, good radiator cap, new radiator core, fan clutch seems to be working but repeatedly dumping coolant into overflow tank and then out the overflow hose to the ground. The temperature gauge shows 220 most times. Can air be leaking into coolant system and cause overheating?

2.) Oil pressure gauge consistently reads 70 at 650 rpm or when hot and running 1500 rpm. Oil pressure independently checked by a mechanic and it read 55. Could the oil gauge be defective? Should the oil gauge be replaced and how difficult is this? Can the oil gauge be rebuilt?

Could these two symptoms have a relation to each other pointing to one single problem?

[Tom H.]

Re: 1972 LS-5 issues

I would say you have two seperate issues. I would have the radiator checked first. Then work from there. Is is overheating at idle or at road speed, or both ??

The gauge probably is giving you a bad read. I believe you can repair them. You can also get new ones. Not really a fun job to get the gauge cluster out, but with some patience, you'll get it done.

[Edward J.]

Re: 1972 LS-5 issues

Scott, my first test would be to check the radiator cap , an improper PSI on the cap will cause a release of coolant, and a rise in the engine temp.you will need a tester for that,maybe you local mechanic may be willing to test it (easy to do)

Take it a step at a time, then as Tom says the radiator, check for flow, a a/c car will be aliitle easier to check, if you have a tank ,then you may want to use a infrared temp gun. as the water flow goes from tank to tank to check the cooling.

keep us posted I sure we can get to the bottom of our problem.

[Tom L.]

Re: 1972 LS-5 issues

If you have, or can borrow, a Stant pressure tester, pressure test the system. That may eliminate a possible head gasket issue. In addition to an improper PSI cap put a new one on or test it. My LS-5 was leaking very little and I didn't even notice it until that fateful day...

[D S.]

Re: 1972 LS-5 issues

Thanks, all. Very perplexing and worrisome issues. Getting to the heart of the situation would ease worries about driving it. The overheationg thing is the biggest concern. LS-5s running hot isn't anything new but boil-overs are a whole new issue. The oil pressure gauge could be faulty and not be anything serious but making sure is the key thing.