Darud35

I've been battling an overheating car, after diagnosing so many other things I finally tested the thermostat. I figured it was fine since it is brand new. Here's an image of the test:



Luckily I had my old thermostat to compare to (on the right). New one won't open nearly as much. I'm debating putting the old one in, or picking something else up. Anyone have experience with a lower temp thermostat? If I'm doing racing will it be necessary?

86 951 Driver

My dad ran a 160 degree thermostat and it never went over the bottom white line. Ran perfect.

Techno Duck

Had the same exact problem after i rebuilt my engine, couldnt figure out why the car was running so damn hot.. bled the damn thing like fifty times (Not even joking!) thinking it was air in the system. The brand new Laso thermostat was not opening completely... here is a picture i took after boiling both of them.

gruhsy

What brand is the good thermostat?

Jason

Techno Duck

I would go with Wahler or Behr.

Replacing that thing SUCKS! So do it once and do it right!

Darud35

I too became a cooling system bleeding expert. I couldn't believe it would be a brand new t-stat. Good lesson to test them first I suppose.

Thanks to a great supplier they're sending me a replacement thermostat even though it's beyond the return period. I went with the 71C. I will be testing it before putting it in the car since that clip is such a PITA.

will951

I am getting ready to replace my thermostat as well. I bought one from AutoZone as it's the only place that has one in stock. I suppose I should test it first!!

fbgh2o

After having so many bad t-stats from new. I just gave up on using one.. Car runs fine....

Black51

You mean you just let the temp needle climb to into the red? I'm too nervous to do that, even if the car's not running hot.

George D

I think he meant he runs his car without a thermostat. Not what I would do, but many folks have done this.

Black51

I just figured that's what would happen with no control...

Scott H

The thermostat keeps the coolant in the engine until the temperature is reached, once it's reached the wax pellet inside melts and the spring will (or should) open the valve, this will allow the water to now flow through the radiator. Without the thermostat in place it would be like having an open thermostat all the time. Speaking in general terms, with modern ignition systems, and in certain climates and driving situations, you may never reach "operating temperature," consequently modern ECUs will adjust timing to compensate.

Example: