Heater

I have a 2001 sihoulette and when the heat is turned on, very little air blows out the vents. However, if I turn the temereature down to coldest, lots of air comes out. Additionally, I wasn't getting any heat at all, at least intermittently, then I changed the thermostate, and it worked for a bit and is now doing the same thing. I have tried bleeding the system, but it is still giving me issiues. The water pump sees to be working fine, and there doesn't appear to be any antifreeze leaking. Also there is no evidence of water leaking into the oil.Any Ideas?

I had the exact same problem on my 98 Trans Sport (same as Silhouette, Venture, Montana).

I never did figure out what was causing the no heat with hardly any air flow on hot but seem to be fine on cold problem.

I ended up pulling the old girl off the road this past December due to the... well no heat issue, bad strut bearings and a leak above the gas tank. I would have fixed all these things in a flash if wasn't for the rotting rockers ! Too bad the engine has 220k and no issues whatsoever, same with the tranny !

So I picked myself up a 02 Silhouette (no heat issues) my ol' 98TS is sitting in the barn now. In the next couple days I might go have a look at the blend gate behind the glove box as I always wondered if that was the cause of my no heat issue. The barn is unheated and its' brrrr out these days.


So getting back to your problem. I figure it's one of four possible problems..

1. (easy) Low coolant or air pocket in the system.. Add and bleed sys.

2. (moderate) Stuck air blend actuator gate/door located behind/below glove box (removal required)

3. (moderate/hard) Heater core plugged/ Need replacement. (requires complete dash disassemble)

4. (hard) Head gasket and/or Intake manifold gasket issues. (requires engine top end disassemble)

Good luck here's hoping you luck out with #1 or #2

Cheers
Wayne