anyone have issues with mr. gasket thermostats

[90mustangfan]

I had a bad hose and I figured while I was replacing my hose, I change the thermostat...I had a 195* stocker in there and It would run at the M. Now I put a 180 mr gasket thermostat and it runs at the first bar above 130..Is this normal?...I had the same therm in another car and it would run at the A...why is this one running so cold, Its a 180* for sure, shouldnt it run at the A mark....could this also be cause its winter and it will take a really long time to get to full temp? anyone have any issues with this therm?

 

[bloopbloob]

mines not a Mr. Gasket, but the old one ran fairly high on the gauge, my new 180* looks like the car never heats up, especially now that its winter, but it did it in the summer also. only time the needle would go over 1/2 was was after a good 30-45 min of HARD running (many 750-5000+ rpm pulls). The stock gauges are notorious for being WAAAAY off.

 

[5spd GT]

I never had an issue, but I used the factory guage.

 

[Fast63]

does your heater blow hot air? If it really is running that cold, the thermostat is probably stuck open. Will it get to that point within 5 minutes or does it take 20? How long have you driven it at one time and it has not been past that point?

 

[cevtv]

I had a 195* stocker in there and It would run at the M. Now I put a 180 mr gasket thermostat and it runs at the first bar above 130..Is this normal?...I had the same therm in another car and it would run at the A...why is this one running so cold, Its a 180* for sure, shouldnt it run at the A mark....

First of all, get a real gauge and see where it really is - then worry about it if it's low.

 

[5spd GT]

Likely, if it is running different right after the thermostat install, the guage is reading what it would.

The chance of the guage going bad in that short of a time is unlikely.

 

[90mustangfan]

Well i have my heater core bypassed at the firewall, So no heat anyway...As for running I drove it a good 1 hr and take about 20min to get to temp. the the thermostat opens when the gauges is at the L, then it goes down alittle, then the thermostat closes, then it will climb back to the L...So the thermostat is opening and closing, It just seems the gauge is reading low....as my other stang with that same thermostat would read at the A...but then again this car has white faced gauges, so possible when I put the needle back I didnt put it exactly right...so

 

[RYC CUKR]

I would get a mechanical gauge and check it with that. The stockers are notoriously inaccurate. Or it could be a sending unit that is on its way out

The Tstat is 15* cooler than the stocker so it should read a little lower but without a real gauge I wouldn't make any definitive decisions.

My 88 with a Mr Gasket 180* and an autometer mechanical gauge runs just a touch below 180*.

 

[LiquidGT]

I put a mr gasket 195* in my newly built motor, it was cold outsde and the temp was at the "L", I had no heat and I was concerned with ring wear. My mechanical gauge read 140* with the mr gasket. I put a stock style in and it warms up fine, I put the mr. gasket in a pot of water and it cracked opened at 180* and fully opened at 195*. I read somewhere else that the mr g. cracks open earlier and other people have the same problem.