Do I need to replace the thermostat?

[Ducaire]

I may have mentioned this before, but my S10 takes a long time to warm up. Even in the summer, when I crank up, if it's been 24 hours since I last ran it I have to let it run a minute or so to get the oil thinned so it will shift good, and that's in the SUMMER!!!
In the winter, I can start it and let it warm up for about 5 minutes or so, and then when I start driving it, it STILL takes awhile before the heater will blow out warm air. Once it does warm up, it stays at around 200 degrees F., and it blows hot air, it just takes freakin' forever to get there. Could the thermostat be worn out?

[Kemi]

Originally Posted by Ducaire

I may have mentioned this before, but my S10 takes a long time to warm up. Even in the summer, when I crank up, if it's been 24 hours since I last ran it I have to let it run a minute or so to get the oil thinned so it will shift good, and that's in the SUMMER!!!
In the winter, I can start it and let it warm up for about 5 minutes or so, and then when I start driving it, it STILL takes awhile before the heater will blow out warm air. Once it does warm up, it stays at around 200 degrees F., and it blows hot air, it just takes freakin' forever to get there. Could the thermostat be worn out?

Ducaire,

Yes, the thermostat is almost certainly stuck open and should be cheap and easy to change.

[Ducaire]

Great. The normal temperature will still be at 200 F., won't it? Is there a certain type of thermostat I have to buy? Or will that not make a difference?

Thanks.

[ZL1power69]

no special one needed but get one that is a 195 degree. make sure when you install it, it is flush in the housing and that the o-ring goes on top of the stat.

[BlazerBoyLT98]

Yup a new thermostat will help your issue but for the extra few dollars I would also replace the radiator cap. Post your results

[Rick Norwood]

Originally Posted by ZL1power69

no special one needed but get one that is a 195 degree. make sure when you install it, it is flush in the housing and that the o-ring goes on top of the stat.

Just as a point of order, my experience is that the rubber gaskets are round (obviously) with a slit that goes around the inside of the gasket and forms a tight "U" shape which fits over the round plate of the thermostat. In other words, the gasket, when installed on the thermostat is actually ABOVE AND BELOW the T-Stat plate because the T-Stat is inside the groove of the gasket. I know there are different styles, but I just wanted to add my

Oh and BTW, using this style of gasket, eliminated the need for Perma-tex or any other type of gasket sealer. Just make sure both the housing and the block are clean and free of any crud (old gasket etc.) before installing the new one.

[old_master]

Newer 4.3's use that design, however, Ducaire has a 1990 which uses the old style thermostat and gasket for all four engine options.