Engine/Transmission (1998.5 - 2002) 99 thermostat

[Ncostello]

Does the 99 model year use a 180 or 190 degree thermostat. The reason I ask is because (although it is getting colder here in IN) I have never noticed the temp guage get up to 190. Even when it was hot out and I first got the truck, it didn't go that high. Then I thought maybe it has a 180. But with the crappy factory guage, I have to guess where 180 is and cant really tell what it is reading. I would have to guess 160 or 170.



Could a bad thermostat cause low engine temps and possibly a bad idle. I dont really know what lower than normal engine temps would do to the other sensors etc. Just a last ditch effort to solve bad idle problem before getting a new VP. . haha.



PS: I had a new 3" aluminized exhaust installed today from the transmission area on back. Lost the resonator and muffler. Straight pipe city!! I retained the 4" factory tail section. Neighbors now officially think I have a semi and that I am nuts. Yeeees!!!!

 

[Riflesmith]

99's had 180 degree thermostats as original equipment.

 

[kluther]

my t-stat had part of the rubber seal wedged in it not allowing it to close. easy to check. ken

 

[CFarlow]

My 99 usually runs around 180 or so until I'm pulling my camper and then the guage get a little more action--sometimes the high side of 190 on steep grades. Yours sounds normal to me.





Chuck

 

[fj40charles]

I would replace the thermostat. There seems to be a high failure rate on the thermostats. Usually, one of legs will be broken. I drove my truck like this for over 2 years and after replacing it, it heats up real quick. Cheap and easy to do.



Charles

 

[Ncostello]

I'll go ahead and change it. I need to flush the cooling system anyway. This would be a good time.



I'm also thinking about doing a KDP fix while I'm at it. That way I can remove about anything I want to with the coolant out of the system.



I'm still checking on whether I have the revised front cover. I may not even have a KDP problem. Better to spend a day doing this than two weeks fixing a busted cover.