Thermostat Replacement

[SteelBlueGT]

My Cruiser wont warm up fast anymore but once it does it the coolant temp stays where it is supose too so I think my thermo is bad!! After checking out the replacement situation I decided on this: Prestone Thermostat - GENERATION 2 776-180
Gasket (o-ring) - Fel-Pro 35588 (10-1227)

It cost me $10.99 at Kragens but it is cheaper to order on line and pick it up like this: http://www.partsamerica.com/ProductD...pe=134&ptset=A.

Will install Saturday after I flush the system good. BTW Radiator cap looks great but I will pressure test it. Will use MOPAR coolant unless there is a better one around for our car.

[purple04]

If this isn't weather-related (doubt it, mine warms up at the same rate cold or hot), It's either a stuck open t'stat, bubble in the system or a sending unit problem. Your plan of attack covers 2 of 3. Check the sending unit while you are in there to cover all bases.

[SteelBlueGT]

Thanks for the advise and I will check the sending unit per my factory maintenacne manual on CD. I doubt that it is a sending unit problem as the gage reads appropriately under all conditions. When I was drving on a trip and traveling for about a half hour at about 80 mph the gage read normal till I went down a large hill and it read two lines under the normal line which for me is the half way line. Whemn I climbed the hill a moment later it went back up to normal. I never knew the thermo closes and keeps the temp more or less constant.

Before this problem my gage went quickly very close to the half way line and stayed there no matter what the engine was doing or the ambient temperature was or if the A/C was on or off.

[Cal Cruzer]

Yeah, just sounds like a stuck t-stat. Used to be when a t-stat stuck it would stick in the closed position. Many are now designed so the default is open and that is where they will stick so you don't blow a headgasket or worse when it sticks. I didn't know that the PT's had one of these but they do make a lot more sense!

[SteelBlueGT]

Installed the T stat and all is well. Te old unit was actually broken and wide open. The top metal piece was alost completely severed at the bottom and it was flopping around. The new unit went in as designed and the gasket or what the call a seal worked good too. Now it quickly goes to one line under midway kinda slowly goes to middle line and stays rock steady there. I think the counter man said Prestone claims that it starts to open at 180* but is not fully opened till 187* if you beleive that!! If you believe Prestone and think the gage is kinda close then one line under the mid point must be close to 180*!

[quicksilverdon]

There's an article in Popular Mechanics that syas going to a lower (180) thermostat isn't a good idea. Will hurt fuel economy.

[SteelBlueGT]

I will let you know but if it starts to open at 180 and fully opened at 187 then it should be close to OK at least. At least it wont open at 160. The Neon SRT boys seem to be happy with this T stat.

[ptTurbo528]

WHAT DO YOU GUYS THINK OF UPGRADING FROM A 180 T-STAT TO A 160... I KNOW ITS GONNA BEEF UP THE FUEL INTAKE ..THE COMPUTER WILL THINK ITS RUNNING COLD. I PUT ONE IN MY OLD CAR AND I KNOW IT SUCKS IT WINTER TAKES FOR EVER TO GET WARM ..SHOULD I DO IT .. I WANNA TRY TO GET AIR/FUEL RATIO UP WITH MY INTAKE ON I DONT WANNA RUN IT TO LEAN SO MY IDEA IS CHANGING THE T-STAT TO MAKE IT MORE RICH...

[SteelBlueGT]

Depending on your mods the GT engine runs pretty rich on itw own. I would check out the air/fuel mixture before I decided to richen up the mixture.

[SteelBlueGT]

The new T Stat works just fine. Got 22 mpg on my trip to San Diego which was half highway half surface streets. Not good but just what I was getting before. My mileage went down for the summer which may be because of the heat and the summer gas formula.