Heat Problem

[SavageCanuck]

I have a 2002 Venture that may have a heat problem. In the summer, the temperature guage is normally between 1/3 & 1/2. In the winter, the guage is normally between 1/4 & 1/3.

Today was the 1st cold day in the area, around 20F. When the vehicle is up to full running temperature, the guage never got above 1/4 & spent a fair amount of time bouncing a little below 1/4, which it never has before.

Now, before the really cold weather hits, should I change the thermostat? Is this something a simple DIYer could do? Took a quick look & it didn't seem too easy to access it.

[cdru]

It's not a trivial task to access. The only times I've ever changed it was when I did my intake manifold or heads. You need to remove the exhaust cross over pipe in order to get to the two bolts. The cross over pipe isn't hard to remove, but you will likely need to replace the 6 studs as they usually are rust welded to the nuts and twist off.

The other possibility is that you have a malfunctioning temp sensor. That is much easier to replace and fairly cheap, you may want to start there.

After you've had your car out for a long drive (long enough to normally get it up to operating temp), is the upper radiator hose hot and somewhat hard (pressurized)?

[justbryan]

Originally Posted by cdru

You need to remove the exhaust cross over pipe in order to get to the two bolts.

Actually, you don't have to remove the crossover...

Another way to get to the thermostat housing is to remove the throttle body (easier than wrestling with the crossover and its rusted studs in my opinion; to each his own). I did this job earlier this year, and found I was able to get to both bolts pretty easily after the TB wasn't in the way. There are 2 bolts that attach it to the intake manifold, and you'll need to pull the coolant bypass hoses off it as well. Alternatively, you could just disconnect the entire bypass pipe from the top of the water pump, and the bracket by the oil dipstick, and just keep it attached to the TB. Either way will accomplish the same thing.

Anyway, a little "I wish I knew that beforehand" I'll pass along to you is that the rear bolt hole on the thermostat housing is SLOTTED, so you don't actually need to remove the bolt - loosening it several turns will do the trick. So, loosen the back bolt, then completely remove the top bolt, and the housing will come right out.

Good luck!

[SavageCanuck]

Thank you for the replies. You've confirmed what I suspected looking under the hood. Changing the thermostat is not a trivial task. Not like when I had my late 70's Chev pickup where it was right up front.

Anyways, it's real cold here now & it seems to be fine. So I'm more agreeable to a flaky temp sensor than the thermostat. But the heats working, so we won't touch what's not broke. At least for the moment.

Thanks again.