So I noticed that my thermostat went bad the other day after my radiator boiled over half the fluid away when I shut off the engine.  I took it to my mechanic and he replaced the thermostat.          
Well, that fixed the boiling problem... But now, everytime I hit the freeway, the temp guage drops down to the bottom (C) and I get little or no heat from the heater.  Idleing and city driving isn't really affected, but it takes forever to heat up after I start up my kick.  And if I head straight for the highway, it never heats up!!

So I concluded that this replacement thermostat is stuck open.  I took it back to my mechanic and he replaced it with another thermostat... BUT THIS ONE IS DOING THE EXACT SAME THING!!  This newest one seems to be stuck open as well!
What the heck is going on??? Perhaps we're missing something?

that is one strange problem?  i drove my tracker with no thermostat and it would still get hot eventually even at highway speeds, and the heater would still work.

The only thing i can think of did you fill the radiator back up maybe it is so low the temp sensor isn't getting a good reading.  

The radiator is full and the temp guage is confirming what blasting the heater is already telling  me... There just isn't enough heat!  If I just sit and let it idle, the temp guage will go to halfway and the heat flows into the kick just fine.  But once I go 65mph or faster- especially in cool weather, the temp guage dips all the way down to the (C) and the vent only cranks out lukewarm air!  And like I said, I'm on my second brand new thermostat to no avail!  

Air in the system maybe?

A hose collapsing?

I'd start with everything cool, pull the radiator cap, start her up, and see what's happening inside the radiator.  At startup, the fluid should just sit there.  Once it reaches operating temp, the thermostat should open and the fluid should start flowing.  

You may also want to take a good look at the hoses at different times (cold, hot) to make sure neither the upper or lower is collapsing.

If you find out what is causing it let me know!!! My Kick has always been like that. I have damn near ran it out of coolant and it did not over heat. Worse case, the gague may hit 1/3 while sitting in traffic in the middle of the summer, and my heater barly warms things up.
Zig

Awsome advice, Jerry, I'll give it a shot today if I get some time!

I'll keep posting my progress in this thread.  I guess I got all summer to fix it.. But its 37f this morning and some heat would be really nice right about now!

I would agree with Jerry, it sounds like air trapped in the system, or a colapsing hose.

Mac

Awsome advice, Jerry, I'll give it a shot today if I get some time!

I'll keep posting my progress in this thread.  I guess I got all summer to fix it.. But its 37f this morning and some heat would be really nice right about now!

BTW, be careful with that cap.  It's OK to run the system from cold to warm without the cap on, but once you put the cap on the system will pressurize and you need to let it cool before removing the cap.

A long time ago I replaced the t-stat in my 86 w/ a suzuki OE unit. I seem to remember that there was a certain way (rotational position) that the thing had to be mounted.  I recall an arrow on the thermostat had to point either forward or towards the firewall.  There was no explanation in the FSM as to why.  I'm at work and don't have my 91s FSM handy to look it up again. Maybe this helps you, I dunno :-/

Ron

Check your fan clutch. At cold tempratures it shoud be free. It may be stuck in locked mode.

I just looked at my post and the one above it and laughed very hard! check out the avatar's! Evil Twins

Actually when I did the power steering the clutch was locked up and I dint know how long. I hope it helps out. I'll get the Kick back this week and will let you know,
Thanks,
Zig

Thanx for all the info guys!  I took a look at my hoses... The bottom one does appear to be a little flat... What does that mean? And how easy is it to fix?  Sorry I'm so ignorant about working on cars... I'm more of a computer guy!

If your hoses feel soft in spots or are flat its a good idea to replace them. Not much money for piece of mind. dont forget all the heater hoses.

I seem to remember that there was a certain way (rotational position) that the thing had to be mounted.

The last time I replaced the thermostat, I noticed that the service manual and the thermostat instructions recommended a different orientation for the thermostat's air-hole.  I think the thermostat's instructions said to face the hole toward the back of the engine, while the SM said toward the front.  Can't remember for sure, but I followed the SM.

If your hoses feel soft in spots or are flat its a good idea to replace them.

Ouch    isn't that gonna hurt? I thought that's what Viagra was fot!