Heat in town, no heat on hwy

[Mark 1212]

I'm in Wisconsin and it's cold. We have heat blowing while driving around town but as soon as we hit the highway it cools off. Back in the "old" days I would think that the thermostat was sticking open. Any ideas??? How hard is it to get to the thermostat?

[vipergg]

That would certainly be the first place to start and its cheap . Just follow the upper radiator to where it connects on the block and thats where the stat is located . Just changed one on my 96 , what a difference in heat and the old one was even setting a code saying it was running too cold .

[earlyrizr]

do you notice a difference in the temp gauge readings between city/highway.I had a similar problem,at slower traffic worked fine but on the highway was colder.the T-stat was broken on one side holding it open,replaced it and new coolant(get the right kind)and good as new,heat all the time.

[Mark 1212]

Thanks guys. I'll be replacing the thermostat Sunday.

[JohnnyOH]

Replaced the stat in my '98 Vger a week ago.
Lots of heat now, and just in time!
I doubt if global warming can keep temps this high into January in Ohio.
Maybe next year.

At first, I had placed the rubbery side of the gasket DOWN, and had NOT bottomed out one bolt. It leaked like crazy.

Placed the rubber UP and torqued the two bolts until they bottomed out. No leaks.

[t_arnold]

I had the same problem with the Wife's 98 Grand Voyager. I replaced the Thermostat. It was closing almost all the way, but not quite. Made a huge difference.