Thermostat Interchangability?

[Hank F.]

I just got a 52mm T-stat for my 93. It came out of a car with 94k miles that is 2 years newer than mine (95). However, it has none of the air toggle holes, despite everything else being copacetic. Should I install it as-is? Or drill a tiny hole for the air to bleed through? I'm stumped. The car it came out of ran like a watch until it was sideswiped 10 days ago. Please any Jedi wisdom will be greatly appreciated. I need to drive to Alberta again, and it's supposed to be damn cold up there this week, so I DO NOT want to be stranded in Monarch or Lundbreck or one of those other minor metropolii that dot the landscape in the wind swept prairie that is Western Canada. Ideas, suggestions or jokes would be greatly appreciated. Thanks, Dave

 

[93rev2sev]

Are you trying to save $7?

The pressure should be equalized somehow. Perhaps purchasing the corerct thermostat would work.

 

[NWGRN94MTX]

Hank,

You definitely need the jiggle valves in the T-stat. If you don't have them it is almost impossible to burp the system after you have opened it up or changed the coolant.

Like the guy above said, why don't you buy a new one? Risking failure on a long trip doesn't seem to me to be worth it.

 

[gmorrell]

Not just any old 52mm thermostat will work in the SHO motor. Beyond the jiggle valves, which are important for allowing air to burp out of the cylinder heads, the most important part of the OEM design thermostat is the bypass valve disc on the backside. As the thermostat opens and admits water to the radiator, the bypass disc closes off the water pump bypass passage back to the water pump inlet.

Without the bypass disc, hot water that should go through the radiator just goes straight back to the water pump, bypassing that rather important cooling step.

 

[Hank F.]

This stat came from a 95 that was running fine. Believe me, things are so tight I squeak when I walk. But I have to get a new stat because my mpg is down to 14 from a high of 32 last summer. In two weeks, I'll be able to give it a 100k AND a new stat, just not now. Ins.- for cars and humans, quarterly taxes and my child support all came due this week. They're usually more staggered, but once in a while when short months and bad economic karma hits at once, sacrifices have to be made. So, there you have it. Will Dave survive- Tune in tomorrow for the next episode of while the SHO smokes........ Brought to you by Loosners Castor Oil Flakes!!

 

[SASHO91]

FWIW, i bought a non-jiggle valve t-stat(didnt know it till i got home should have looked) so i just drilled a couple small (cant recall the size, probably about the size of a pens ballpoint, if that helps) holes, and put the t-stat in with them a 12o'clock... ran fine.

 

[URLACHER54]

does where you position the jiggle valve make a difference

 

[SASHO91]

well.. air is lighter than water....

 

[Hank F.]

Well the deed is done. I know it seems absurd not to just get the new one and slap it in, but believe me, imagine what it would take for you guys to do what I did.......a situation way beyond *****, yes? That's what I looked at yesterday. I'm emailing this on the road north in a rest area with wifi, and so far so good. Thank you again, this is the most supportive without being judgmental car site on the net(even tho most of you were thinking 'he's crazy'). I'll post the mileage when I get back next week. Thanks again

 

[Shoaz]

does where you position the jiggle valve make a difference

Up.

 

[SHOZ123]

A properly sealed cooling system will purge itself of air. When filling undo one of the small TB hoses and elevate it. Slowly add coolant until it comes out of the TB hose. then attach TB hose and completely fill the system.

I've ran non jiggle valve T-stats with no problem. If the system is not sealed or leaks air in on cool down then this will not work.

 

[Shoaz]

A properly sealed cooling system will purge itself of air. When filling undo one of the small TB hoses and elevate it. Slowly add coolant until it comes out of the TB hose. then attach TB hose and completely fill the system.

I've ran non jiggle valve T-stats with no problem. If the system is not sealed or leaks air in on cool down then this will not work.

Or if it boils a bit.

 

[SHOZ123]

If it is boiling then the systems pressure is not being properly maintained.

 

[AREA 91]

FWIW, i bought a non-jiggle valve t-stat(didnt know it till i got home should have looked) so i just drilled a couple small (cant recall the size, probably about the size of a pens ballpoint, if that helps) holes, and put the t-stat in with them a 12o'clock... ran fine.

I also have drilled a small hole at the 12 o clock position. Never had a problem. This is all I had at the time. All my SHO's get Motorcraft T stats now.

 

[Shoaz]

If it is boiling then the systems pressure is not being properly maintained.

Or it's hot.

Maintaining pressure just raises the boiling point, it doesn't make it boil-proof.

IIRC the stock cap is only 10-15 psi or something like that. Bondurant had a 25 psi cap on mine and it still boiled. When it does, the gas needs to be able to get out of the block quickly, and the jiggle valves help with that.

 

[SHOZ123]

Sounds like too much heat input to me.

Or an iron block.....