Ok, this is a post about my '95 S-10, but I think it is critical and that you guys will be able to help.

I have 4.3L V6, so it is pretty much 3/4 of a 350 V8. It WILL NOT get to operating temperature. I went to change the thermostat and when I pulled of the housing it was closed. I put in the new 180 degree thermostat, hoping that the old one had been stuck open and some miracle had caused it to close when I went to look at it. It still won't get above 150-170 degrees. Radiator is full. The thing is that the fan runs all the time. It should be on a thermostat too as far as I can tell, the engine used to easily warm up to around 200 and then get to 210 if I pushed it, then cool to like 180 and then warm again to 200. All of the hoses get real warm, but I dont think that the thermostat is open. The fan clutch is disengaging though, it spins free when the truck is off, it even spins for a while after I shut it off.

What is going on here? Is the thermostat for the fan shot? If so, where is it? How much does it cost? I will contact NAPA later this morning (like, after they open) but I really want to make it to the regionals in KS this weekend. My 'Velle isn't done and my truck is my only other ride. PLEASE HELP!

Thanks!
Nat

PS - should I consider changing to an electric fan? In your opinion, what would be the maximum I should pay to fix my fan?

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Restorin' a '69 Malibu/SS Clone
396 - .030 over
Complete Performer Package, Closed Chamber Oval Heads, and way to much invested.
700-R4, Bow Tie or Phoenix?
New Front Brakes!
And frame is bare right now, reassambled soon!

How are you checking the temperature? It sounds like you may have an inaccurate temperature gauge. Can you get a thermometer to put into the radiator tank to verify the temperature?

How do you recommend measuring the temp of the radiator? The resevoir doesn't seem to be gettning warm. Is there a tool or something that I can use?

Thanks,
Nat

I would agree with the first reply, check and verify the accuracy of your gauge and/or the gauge sender.

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1969 Camaro 383/365HP, B/W T-56 Six Speed, 12 bolt, Eaton Posi! 3.73, 4 Whl. Disc brakes, console w/Auto Meter gauge package, tach, clock, tilt wheel, Black Deluxe houndstooth interior, rear window defogger.

I had a 90' s-15 Jimmy with the 4.3L. I had a bad thermostat and it would only get above the 100 degree mark on temp. Figured my guage was bad, heater seemed to put out heat. Well winter came and it really did not put out that much heat afterall.

When I pulled the cover of the thermostat while the engine was warm, I could open and close the thermostat. But when the thermostat finally got to air temp, it acted like a new one in that it was very stiff to open. My guess is that is was opening at a very low temp. Replaced with a new one and I was into the 220 degree range. Hmmm, not right either. Turns out the waterpump was going bad also. Replaced that and it ran about 190.

If the thermostat did not open, it would over heat. Your new thermostat could be on the low end, maybe try another one.

My resevoir never got hot.

If your fan is like mine, it is a viscous (sp?) clutch fan. It does seem runs at all times. When it's cold, or idle, the fan clutch grabs more and the fan blades turn more. When higher temp or speed, the clutch grabs less. (That's the way I understand it.)

Good luck.

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J Enga
64 Malibu SS 327 (http://www.chevelles.com/showroom/enganeer64MalibuSS1.jpg)
400 build up (http://home.earthlink.net/~enganeer/400_small_block/400_small_block.html)
Instructions?...All I need is the exploded view

<BLOCKQUOTE>quote:</font><HR>Originally posted by R&NMalibu:
Ok, this is a post about my '95 S-10, but I think it is critical and that you guys will be able to help.

I have 4.3L V6, so it is pretty much 3/4 of a 350 V8. It WILL NOT get to operating temperature. I went to change the thermostat and when I pulled of the housing it was closed. I put in the new 180 degree thermostat, hoping that the old one had been stuck open and some miracle had caused it to close when I went to look at it. It still won't get above 150-170 degrees. Radiator is full. The thing is that the fan runs all the time. It should be on a thermostat too as far as I can tell, the engine used to easily warm up to around 200 and then get to 210 if I pushed it, then cool to like 180 and then warm again to 200. All of the hoses get real warm, but I dont think that the thermostat is open. The fan clutch is disengaging though, it spins free when the truck is off, it even spins for a while after I shut it off.


<HR></BLOCKQUOTE>

This sound like what I just had not to long ago on my 96 GMC 4.3 After you had the car running for some time (operating temp range) then shut it off. See any coolant come out from a drain tube by the tranny. Anyway since the GMC was still under warranty, took in for trouble shooting. Found out had a very small coolant leak in the intake manifold. Replace gaskets and now the temp stay's around 180*.

Vinny



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1970 350 Project Chevelle

1994 TransAm G.T. LT-1 with all the goodies that make it gooooooooo.

1990 Camaro RS 3.1 Daily Driver

http://community.webtv.net/vinnro/VINNYS1994TRANSAM

First of all your truck is supposed to have a 195 thermostat in it. If you don't the engine will not go into closed loop and run properly. After putting in the right stat, Have sombody hook up a scan tool to the diagnostic connecter and read the temp from the pcm coolant sensor to verify that your temp gauge is accurate. The coolant sensor for the pcm and temp gauge are seperate. If your temp gauge does not read right it could be the sender or the gauge. There is a resistance value that you can hook up from your sending unit connector to ground to make the gauge go half way to check the acuracy. let me know if you need the value # and I will get it. You can pick up a test resistor at radio shack.