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Thermostats!!!!

Ecomike

Ecomike

NAXJA# 2091
NAXJA Member
Location
MilkyWay Galaxy
I have read a lot thermostat bashing here lately, LOL.

I got the new CSF 3 row radiator in tonight, and went and picked up new hoses for 89 repair (plastic tank on 2 YO aluminum-plastic tank Rad died a few days ago), and decided the Thermostat may have failed closed and killed the radiator, or the over heat from her driving it with the leak might have killed it open, so I decided to go with a different T-Stat this time after reading all the stories here.....teeth nashing, bashing, and so on, instead of just using what I have always used, a cheap Duralast T-Stat. Note, that I have not had any known to me T-stat problems over the last 35 years.

So I was doing some reading and decided to get a Mr Gasket 4364 Balanced T-stat after reading how it claims to deal with variable pump pressure better than standard T-stats.

So I thought I would start a thread on T-stats and who has had what luck with what brand, and so on. So this thread is not about your cooling system issues, but is to about, the good, bad and ugly of different T-stats used in our jeeps!!!

"Mr. Gasket high-performance thermostats are designed to resist large variations in coolant pressures that can occur at high rpms. Under these conditions, coolant temperature and pressure fight for control of the thermostat, keeping it from opening at its designed temperature. These balanced high-performance thermostats feature brass-and-copper construction, and open at the right temperature regardless of engine rpm."

http://www.summitracing.com/parts/MRG-4364/

I have read threads here over the years where people were having temperature swing issues after upgrading water pumps and radiators...etc, that they tried to solve with different T-stats.......and the Mr. Gasket info struck a cord with me. Not sure if it is BS, or what, but I do recall many posters having issues with wild temp swings after putting in better radiators and coolant pumps.
 
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I have had 2 Stant stats fail on me in my 88. The Jeep wouldn't get up to temp ever and it was slow to warm up. Tried one with 1/8" bleed holes drilled at 12:00 and 6:00 and one without the holes drilled.
Finally bought a new one at the dealer and the Jeep warms right up and the heater blows warm very quickly. I'm planning on replacing the Stant in my Comanche with a factory unit as a result. It takes alot longer to warm up than the Cherokee now does. FWIW, both Jeeps have new radiators.
 
cruiser54 said:
I have had 2 Stant stats fail on me in my 88. The Jeep wouldn't get up to temp ever and it was slow to warm up. Tried one with 1/8" bleed holes drilled at 12:00 and 6:00 and one without the holes drilled.
Finally bought a new one at the dealer and the Jeep warms right up and the heater blows warm very quickly. I'm planning on replacing the Stant in my Comanche with a factory unit as a result. It takes alot longer to warm up than the Cherokee now does. FWIW, both Jeeps have new radiators.
Click to expand...

How old (yrs or miles) were the stants when they failed?
 
About 10 years ago, I replaced a bad thermostat with one from the local auto parts store, one of the cheaper ones on the display tree. The temperature kept bouncing up and down by about 80* after a cold start up for quite some time. The XJ was also slow to come up to proper temperature. I replaced it after about 300 miles. This time I bought one from the same store but a more expensive one. It did exactly the same thing. Visiting family in Connecticut in January 2002 with several feet of snow on the ground added to my unhappiness and frustration. The third replacement in about 2 weeks was from the dealer. I was so happy with it that since then, I use dearler only thermostat when I need one.
 
So far I've been running a 'carquest' brand T stat with great success!

We go duning alot so its tough on the motor and I have zero cooling issues.
 
I buy plenty of aftermarket parts, but I buy my thermostats exclusively from the Jeep dealer.

Never had a failure in 38 years and they keep the coolant temperature more steady than many other brands.
 
birchlakeXJ said:
I buy plenty of aftermarket parts, but I buy my thermostats exclusively from the Jeep dealer.

Never had a failure in 38 years and they keep the coolant temperature more steady than many other brands.
Click to expand...

If you never had a T-stat fail in 38 years, why did you need to buy one from anybody?

LOL
 
If you've got a Napa Auto near you I've switched to the standard t-stats that they supply. Been running them for 10 years now and very happy, I was having all sorts of issues on both cherokees and TJ. Now they all have fast warm up cycles and are bang on proper temperature. Not actually sure what brand they supply maybe someone else can chime in here.
 
Ecomike said:
If you never had a T-stat fail in 38 years, why did you need to buy one from anybody?

LOL
Click to expand...


Nice catch ... :laugh::laugh:

Its OK Birchlake ... we know what ya meant ... :)


Ecomike said:
Nice write up with PICTURES!!!! LOL
Click to expand...

Yes ... they all, seem to have good web designers and advertising agencies .. ;) ;)

... and amazingly ... they all, claim to make the bestest ever, thermostats in the world ... :D


The thermostat supplier to Mopar would be interesting info ... and - whether its been different suppliers over the years.


Good and bad experiences with the same thermostat brand ... might be attributable to the fact that ... from my looking through spec/sales info ... most of the U.S. brands offer an "economy" and a "premium" version of the same thermostat ... and Im pretty sure the description, "economy" - has nothing to do with fuel use ;)

NAPA thermostats appear to be Stant ones for the most part .. whether they're, "economy" or "premium" versions ... I have no idea ... http://www.napabeltshose.com/index.cfm?location_id=1000

Anybody heard of Dayco t'stats ??? ... Not listed on the U.S. website so Im guessing Dayco t'stats down here are just somebody elses ... in a new wrapper.

.... as are the very common, widely used, Tridon thermostats down here ... which are "premium" versions of the U.S., MotoRad t'stats.

Personally ... I wouldnt use a "failsafe" t'stat in an XJ ... Since, as they are s'posed to "fail" open, when things get too hot ... they are likely to "fail" - fairly often in some XJ's ... :D

Jiggle Pin/Valve is a handy thing in a t'stat and I prefer a t'stat with one factory fitted, rather than drilling holes ... and more than one hole is not nescessarily a good thing ...

If the t'stat looks like swiss cheese - then flow from startup, is increased slightly ... as is warmup times etc, ... Effectively, too many or too large a hole ... causes the same issues as a broke t'stat - that is stuck slightly open.

The factory fitted 195* is at least as reliable as other brands Ive used .... but since chrysler only offers 180* or 195* t'stats in their parts line up ... I'll use a brand with a 190* or thereabouts.
 
"Personally ... I wouldnt use a "failsafe" t'stat in an XJ ... Since, as they are s'posed to "fail" open, when things get too hot ... they are likely to "fail" - fairly often in some XJ's ... :D "

2 on that one!!
 
Okay, okay......I can take the hit! Yes, going 38 years with the same thermostat would be quite a feat. But I'm sure some clown has done it!

To clarify, I've bought many a Jeep stat OVER a period of 38 years and never had a fail! Is that better?

I don't know who manufactures the stats for Jeep but I'm pretty sure I saw "MEXICO" stamped on the last Jeep stat I installed. Doesn't tell us much though, as there are plenty of U.S. companies that manufacture in Mexico to take advantage of cheaper labor rates.

And yes, I like the jiggle pin in my thermostats too! Pretty sure that Jeep wouldn't be ordering this on their stats if it didn't help stabilize coolant temp......Every penny counts with mfg. costs. I worked for a company (Honeywell) that supplied OEM engine management sensors to Chrysler and GM, so I know that very well!
 
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Ecomike said:
I have read a lot thermostat bashing here lately, LOL.

I got the new CSF 3 row radiator in tonight, and went and picked up new hoses for 89 repair (plastic tank on 2 YO aluminum-plastic tank Rad died a few days ago), and decided the Thermostat may have failed closed and killed the radiator, or the over heat from her driving it with the leak might have killed it open, so I decided to go with a different T-Stat this time after reading all the stories here.....teeth nashing, bashing, and so on, instead of just using what I have always used, a cheap Duralast T-Stat. Note, that I have not had any known to me T-stat problems over the last 35 years.

So I was doing some reading and decided to get a Mr Gasket 4364 Balanced T-stat after reading how it claims to deal with variable pump pressure better than standard T-stats.

So I thought I would start a thread on T-stats and who has had what luck with what brand, and so on. So this thread is not about your cooling system issues, but is to about, the good, bad and ugly of different T-stats used in our jeeps!!!

"Mr. Gasket high-performance thermostats are designed to resist large variations in coolant pressures that can occur at high rpms. Under these conditions, coolant temperature and pressure fight for control of the thermostat, keeping it from opening at its designed temperature. These balanced high-performance thermostats feature brass-and-copper construction, and open at the right temperature regardless of engine rpm."

http://www.summitracing.com/parts/MRG-4364/

I have read threads here over the years where people were having temperature swing issues after upgrading water pumps and radiators...etc, that they tried to solve with different T-stats.......and the Mr. Gasket info struck a cord with me. Not sure if it is BS, or what, but I do recall many posters having issues with wild temp swings after putting in better radiators and coolant pumps.
Click to expand...

(No edit to OP - I just hit the wrong button.)

The only thermostats I've heard to "fail open" are the Stant Fail Safe models - everything else "fails shut."

I've had good luck with Stant and RobertShaw in the past - good enough that I'll keep using them (I think the Mr. Gasket ones are rebranded RobertShaw pieces? May be dated...)
 
5-90 said:
(No edit to OP - I just hit the wrong button.)

The only thermostats I've heard to "fail open" are the Stant Fail Safe models - everything else "fails shut."

I've had good luck with Stant and RobertShaw in the past - good enough that I'll keep using them (I think the Mr. Gasket ones are rebranded RobertShaw pieces? May be dated...)
Click to expand...

The Mr. Gasket I bought yesterday IS made in China, listed on the back. I tested it last night several times.
 
I've had a Robert Shaw one in my XJ for about 8 years now. Works great. 195*. Just make sure the one you get has the little bleed hole like the OE one.
 
I got my '96 five years ago, and the first thing I did was new rad, hoses, water pump, and t-stat. Temp would climb past 210 for about 30 seconds, then snap back to where it belonged. Did this for a few years, no overheating. Two years ago the pump started to weep, so I replaced it again, and installed a dealer t-stat, with the check ball. Temp comes up now and stays where it belongs, no spike. That's the only one we'll use now.

I've put this out there before. I had to put new lifters in my '92, at about eleven years of age and 130k miles. While the head was off, I was cleaning everything up, and noticed the rear coolant passage was almost completely clogged with coked-up anti-freeze. I chipped it all out of the block and head, vacuumed out the debris, and reassembled it. It ran warm before, but never overheated. Afterward, it seemed to run much cooler, but still, out of our four XJs, has the best heat in the winter. I know it's a little drastic to pull a head to look for build-up, but I was surprised at what I'd found.
 
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