althewiz

On my stock 57 FI Corvette, when I do a cold start, the temperature will go off gauge (greater than 220) over a 5 minute period. When I shut off the car, let it cool down so temp is below 200, then restart, temp stays are 180. I swapped out the thermostat but problem remains. Any ideas?

Crunch527

Check the wiring for the gauge and if that looks good then maybe swap the temp sensor on the block.

wmf62

temp sensor on the block?
Bill

ejboyd5

Perhaps the thermostat is reluctant to open on the first start of the day, but when finally opened will work properly, To ease this problems some folks will drill several small holes in the rim of the thermostat to allow a slight flow of water before the the thermostat itself opens.

Frankie the Fink

I would have run it without the thermostat until the issue is identified and then monitor the temp with an I/R temp gun at the T-stat housing...
Really only two things going on with cooling: a) air flow, and, b) water flow....

Your issue is b IMO. However, if a 57 has a fan clutch check that too...

jim lockwood

I've seen this before. It's almost certainly the thermostat being slow to open. My suggestion is to swap thermostats again, but this time buy a different brand.

bj1k

Nobody seems to know what is the correct temperature sensor . I have tried several that I was told at different auto parts stores were right and the gauge is still not accurate .

dcamick

I agree!!!

Dan Hampton

Good point. Some thermostats are designed that way. In 1972, I purchased a new Datsun 240Z. On start up the temp gauge would swing over to 210 and then relax back to 180. The manual said that if the gauge reading stays at 210, just let it idle until it returns to 180. The curious thing is that when I replaced the thermostat years later with a non OEM, the needle would never rise to that 210 level. In cold weather the car, after the change, never idled very well in temps that were below freezing. There was a method to Nissan's madness.

Robert61

61X

It's been a while but isn't it possible to install those thermostats upside down ?

althewiz

Apparently, the problem was a slow opening or sticking thermostat. I replaced with a Mr. Gasket Balanced High Performance Thermostat (#4364), Problem solved!

Thanks for all the good advice.

jim lockwood

Is that Thunderhill in your avatar?

althewiz

Yes, good call! That photo is from one of our early 24hrs of Lemons races at Thunderhill. The car is Tinyvette, a 1971 Opel GT themed as an ALMS Corvette. Ten years later, after some modifications and lots of body work, the car is still competing although I have since retired from my "racing career." The car's latest claim to fame is a double Cannonball Run from Lemons Headquarters in Emeryville,CA, to the Red Ball Garage in Manhattan then to Redondo Beach, CA, two drivers. Started on a Wednesday, finished the following Monday, 6,153 mi.

Oops, Sorry, didn't mean to steal my own thread!

jim lockwood

I think forum rules permit you to hijack your own thread. You probably won't be banned.

Turns 12 and 12A. I've been thru them many times.... maybe as many as 1000 times, now that I think about it.

Your Tinyvette looks too nice to be a Lemons car. Seriously. I've seen some goofy junque at Lemons events.

The fact that your car has piled on so many miles is a tribute to your car prep. Preparation, preparation, preparation.... the three secrets to having fun at the track.