What is it with me and Thermostats

[Fred]

Day before I drove back and forth to Denver, 85 mph, no problems.

Today, I have to have my kid in Westcliffe at 8 am, and it starts running hot. We made it there, but I discovered I had left my cellphone at home, so there was no possibility of help.
It kept running warmer and warmer on the way home, stopped once outside of Penrose to let it cool off. Running the heater full blast helped so I left it on. Had the electric fan adjusted to run continually.

Made it home, and it never quite got in the red. The radiator was hot, but not in the red zone. Let it cool off, pulled the thermostat, yet another one that wouldn't open. Not even a year old. Same thing as last year in the San Juans. New Thermostat seems to have fixed it.

FWIW, my local mechanic swears by CarQuest gold Thermostats. Since he is the kind of mechanic that guarantees his work, I tend to believe him. I'll put one in next summer.

Fred

[RockyCodeHead]

How many miles on the rig? I had 177,000+

I fought and fought to solve my overheating problem. I hard wired the electric fan on a switch, replaced thermostats, fan clutches, hoses, etc.

Hasta << Me beating the dead horse!

Several people recommended what I am recommending....

If the clutch doesn't do it, and a new thermostat doesn't do it, and the coolant cap is sealing properly and coolant isn't leaking out, replace your radiator. It was the best $125 I could have spent and it solved my problem completely!

Just my 2 cents...
-Rob

[YosemiteMatt]

Definetely check out the cap on the overflow resevoir. That was my problem. Fixed it up nice.

[Fred]

It definitely was the thermostat. Radiator, thermostat, and fan clutch all went in last year. I've replaced all the cooling stuff on two occasions in the last 16 years. :)


Fred

[5-90]

What year? RENIX (1987-1990) is well-known for keeping an air pocket in behind the thermostat - which screws things up. Search up for my posts on thermostat drilling to find out how to make this self-correcting, or jack up the rear end to "burp" it at the thermal sensor at the back of the head.

Drilling the thermostat takes two minutes (if that...) and can help anything with a thermostat in place. It will help prevent air pockets from forming as well.

Also, just because your radiator is new, doesn't mean there might not be something wrong (pinched core tubes or somesuch.) If you have an IR thermometer, use it to take "temperature gradients" across your radiator - there should be a steady decline going downwards and to the driver's side. If there is a sudden rise or drop, that indicates a plugged core.

WRT using the heater - you did good. Your heater core is a little radiator anyhow (first time I was dealing with a clogged XJ radiator was sitting in traffic, coming back from Sacramento, in late July. Ugh - running the heater in 100* with the windows down was Hell...) Just turn it on as soon as you note that you may be overheating - the sooner you catch it, the better it will work and the longer you can get away with running.

[Hypoid]

So what brands have failed you Fred?

[Fred]

Stant, and Mr. Gasket, which was a balanced thermostat. The Mr. Gasket actually flowed too well when it worked. I had to pull it out last winter to get any heat.

Fred

[aldous]

Bumping an old thread, searching on stant which I know is the recommended brand by several of you here now.

I was at Autozone for other things and they did not carry them, so I bought the top of the line that they had, which was failsafe brand made by motorad. Designed with a little tab that locks it open if it overheats.

So the day I put it in, running at perfect operating temp up the side of i-70 to check it out. Everything looked great. Next day it would not get up to operating temp, so I pulled it and it was locked open.

Just a piece of junk? It was $13 so double the cost of the Stant. But I do like the idea of sticking open and not closed if there is a problem. Take it back and get a Stant?
On some other forum someone was talking about a RobertShaw brand being able to withstand higher temps/made for racing, opinions there?

Related question, someone told me running with it open would be fine but waste gas, why would that be? Would that be the same principle with the drilling method mentioned above or would it not be enough fluid at that point to matter?

Thanks.

[Hypoid]

Related question, someone told me running with it open would be fine but waste gas, why would that be?
Thanks.
The ECU optimizes at operating temperature. Until then, you are running on pre set values that are programed into the ECU.

Maintaining that required temp also reduces engine wear.

So far I've been lucky with T-Stats. I never had a defective one from the box, for any brand. Given the failure rate of newer parts, I'm thinking I should keep the old ones that worked. :)

[in4aride]

my tstat i just put in is failed open again. 3rd one in 2 months. getting old.
it definitely kills mpg, i was getting 17-19 on average and now barely get 12....
i dunno what to get to put in there either

[DutchVDub]

I always had good luck with stant tstats. Only time I had one fail was after seeral years and it had actually come completely apart. Made fora cold drive back from NE in November.

[aldous]

Thanks Hypoid, that makes sense on the fuel question. And yeah, I got about 2/3rds the mileage out of this tank of gas.

[in4aride]

anybody know best place to pick up a STANT?
i was told to get it from dealer? dont see why they would carry anything btter than parts store?

[aldous]

Yeah there's available at Advance. Guess I'm going to do that, have to pick something and go with it...

Also found they are available at Woody's online, but they did not answer their phone, don't know if they have a retail place here.

[Kittrell]

I've never had any issues with the Mopar t-stat..........:dunno:

The OEM one never went south in my '99 at 120k. I replaced it anyways when I overhauled the cooling system. As far as I know, this one is still pluggin' along.

http://www.hesco.us/shop.asp?action=details&inventoryID=43066&catId=7969

[old_man]

Fred, maybe you're just getting in touch with your femine side. Every female I have ever know had a screwed up thermostat. :jester: