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the xj i just bought also runs at 180 to 190, it takes a long time to heat up in the morning, i was thinking about changing out the tstat but i think i might put something in front of the radiator instead as it is missing the electric fan and im not sure how its going to do this summer. thoughts?

91 Laredo

I called the stealer and they want $18 for the t-stat. I tried to ask if they know who its made by (i.e. Stant makes t-stats for Mopar) and the parts guy didnt know. I tried to confirm the degree of 195 and he didnt know......

I did notice that my original T-stat had a hole on top with a little ball, I assume this is some sort of bleed hole? The Stant didnt have it.

Are Stants decent T-stats? If I pull and replace should I go with OEM or try another Stant?

Thanks.

okcjeeper

If it is a factory t-stat it is a 195 since that is what they came with.

jpdocdave

that bleed hole usually should be up, and if the o.e had one, get one with it. some parts guys are idiots, they should be able to answer those questions. for $18 i'd just get the stealer's t stat

BuckB91XJ

$18 is highway, friggin, robbery for a T-stat!!!!! That is why you don't by upkeep parts from the dealership. Stant is a good brand. I have always used Stant T-stats and Radiator caps.

91 Laredo

Update -

I tried to bleed the cooling system some more today. Parked on an incline and jacked up the front end (drove on the freeway first to get it warmed up).

Heres what I did -

Turned on the heat to full hot and high

Pulled the cap off and reved the motor and massaged the upper hose


This is what I noticed -

A few bubbles coming up, nothing major.

Upper hose is hot, lower is cool to luke warm

Cap never got hot after running for 30 minutes or so. When I had it off the coolant wasnt even hot, it was warm.

Gauge read about 200 +/-

Drove around and dropped to about 180. Was 190 on the freeway and would eventually get up to 210 in traffic.

Went to Napa and and they thought t-stat may have an issue. But they have never seen one go bad right out of the box. Felt the premium stant stuff was pretty full proof.

FrankSchmeiser

I had one go bad on me right out of the box and I bought it at NAPA!!!

Shawnc16

210 degrees is perfect in traffic. You shouldn't see it get any higher than that. Everything seems normal. I'd say you have nothing to worry about.

91 Laredo

Yea, It seems to be improving somewhat over time. I probably leave it alone for a while and see what happens. Its a fail safe t-stat so if it gets stuck it will be in the open position which is better than the other.....

91 Laredo

My temerature still doesnt sit where it should so I went to the stealer and picked up and OEM t-stat/gasket ($15 for both )

The OEM gasket has some RTV looking stuff on already on the gasket. I spoke to a knowlegable service tech and inquired of RTV was needed and he said not to use any.

What gives, my manual says to use it but he says dont?

I only want to do this one more time so is it needed?

mycherokee1989

I wouldn't use RTV, because its not really needed for this area, unless your housing is bent or something. You will also have a harder time cleaning it out if you do need to down the line get in there. Just get a normal gasket, thats what I have.
I honestly don't think this is really a problem man. It just shows that you have a good system. mine is always below the middle mark(210). It won't effect your engine at all and... well... just not a problem.

91 Laredo

Update -

Replaced T-stat with factory Mopar unit and bled the system. The temp is still about the same. Starting to wonder if there is something wrong with the gauge.

It runs around 210 at idle, but when I drive it drops down considerably to around 180 ish.

Did not have any issues before replacing it and the radiator. It ran hotte before, but the radiator was original with 145k on it. Maybe since this one is new it flows better thus runs cooler?

mycherokee1989

You have nothing to worry about. It ran hotter, like you said, because It was all old equipment, and now with a new radiator, coolant will flow better, and cool down.
When it is dropping down, it is just the thermostat opening up and then the coolant flowing around. When you see it going up and down, it is just the thermostat opening and closing. Especially if you have a 91, it won't stay constant and on the dot like newer cars do.

96 XJ Sport

I had a similar experience with the temp fluctuating after replacing the entire cooling system except for the fan clutch. I attributed it to the greater efficiency of the 3 row radiator. T-stat would open and close running down the highway when it's cold outside. Then at idle it would creep up to about 220 which wasn't too bad, but I didn't like the idea of a 30 to 40 degree drop in temp within a matter of seconds. Then I put a new fan clutch on which put a lid on the upper end of my temp range at idle...now about 205 is as high as it goes at idle no matter what.

The t-stat still opens and closes running down the highway on cold days, but the temp just bounces slowly between about 190 and 205 which doesn't bother me. I feel like the fan clutch **** as I've posted this in several cooling related threads, but check it out if you haven't replaced it already. I was shocked at the difference it made on mine.

91 Laredo

Cool, literally

I wont sweat it anymore and just drive it. The radiator I bought is a CSF, however its not the 3 core. Dont really know what it is but seems pretty beefy. Its almost identical to the one that came out which was heavy duty due to the tow package. I read somewhere that they were a 2 core? I dunno.

I think the fan clutch is good as it as quite a bit of tension left in it, but may be something I look into down the line,