Whoops! Overheatin' :-(

[GOAT72]

On Friday night I cruised for about a half hour. Outside temperature was 83-degrees; a hot Virginia night. After stopping at a few traffic lights the '72 400cid got hot and shut down suddenly.

It did not boil over, but it did shut off and was real hard to crank over again. Luckily, I fired it up again and drove straight home.

The GTO had never done this before, but then it was in Massachusetts until last fall -- where the nights are much cooler.

Yesterday I drove 40 miles to a show in Marshall, VA. (... 120+ cars, ONE Pontiac: mine. (Sheesh... Chevy, Ford, Chevy, Ford...with an occassional Olds and Mopar.) http://www.yenko.net/ubbthreads/images/graemlins/dunno.gif
Anyway, the car "teetered" on the edge of overheating again, but this time I was noticing jerks, (and I don't mean Charlie, I mean the car was actually jerking slightly). http://www.yenko.net/ubbthreads/images/graemlins/wink.gif

I'm now thinking I may have a fouled plug.
http://www.yenko.net/ubbthreads/images/graemlins/confused.gif

This would cause the engine to run hot, correct?
Of course, I checked the fluid levels.

In running hot it consumed lots of oil too. The round trip saw a 1-qt. drop in the pan level.
http://www.yenko.net/ubbthreads/images/graemlins/eek.gif

Any advice from you Poncho or GM A-body dudes would be appreciated.
http://www.yenko.net/ubbthreads/images/graemlins/biggthumpup.gif

Thnaks!
Mac

[Pantera]

On a car that has/is not been driven much you should always consider the thermostat. They are bad about working one time then the next time you drive it they may not open.

You might try disable/taking the center out of a old one and putting that back in place of the original and see it that is the problem. You will find the car will be a little cold natured when you first try to drive it somewhere but you can overcome that just by letting it set in the driveway and warm up. At least it won't lay down on you somewhere so easy. If you are up north you may have to run one most of the time.

Most older cars will work fine with out one in place. You just need the outer ring of a theromostate to slow the water down just a little so it will cool better.

The other place to watch is the radiator can develop crud and plug up from just setting and not being driven on a regular basis.

You might try draining it of the old antifeese and use water and a good radiator flush and then put new antifreese back in it with the thermostat trick I mentioned.

A fouled plug should not cause what you are describing. Trust me I have drove too many miles on a dead plug and never overheated.

Setting in traffic and too lean will do it sometimes but if you can keep moving you should not have a problem like that.

Over heating is usually a fan belt or a theromastat or a blown head gasket. You can for sure blow the head gasket if you don't notice the overheating and keep driving it.

I have drove many miles on a car on the highway with out a fan at all. You just can't be stopped at a light for long though. So if you are overheating on the highway you probabley need to do a compression test. Start with the fouled plug hole first. That might be the one that is bad.


Good luck
Pantera