coolant temp wont get hot

onebaddmaxxx

Active member
Feb 22, 2009
1,212
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Cecil County Md
What is your guys coolant temps going to when its hot?

My truck has 207k on it, it has original thermostats in it, Its 50 degrees outside here in maryland, and normal driving im only getting to 151 degrees logging it with my v2. Afraid when it gets too cold I will struggle to have heat. I had drove for about 30 mins so it def shoulda been up to temp by then. Even when it was 90 degrees this summer, it only ran about 175-178 degrees. Coolant is new as i just did a water pump and radiator. Should I look into changing both stats?
 

Chucky797

Member
Oct 30, 2013
81
1
8
New Bern, NC
I have the same thing happen to my truck. Even if it is in the 80's it doesn't make it to 210 at all. My buddies truck is the same way as mine. It did get up that warm last week while I was towing another car. If i remember correctly diesels run cooler then gas engines.
 

Kspen90

<<<got turbos?
Jul 14, 2011
1,433
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Burleson, Tx
change the thermostats. they have a rubber seal around the plunger that deteriorates and lets the coolant free flow
 

Dozerboy

Well-known member
Jun 23, 2009
4,892
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TX of course
Ya time for new tstats would be there I'd be starting.


Diesels are actually better with more heat in the engine. Our Tstats open at 180 and 185.
 

OregonDMAX

NOT IN OREGON, NO DURAMAX
Apr 28, 2013
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Goodyear, AZ
Ya time for new tstats would be there I'd be starting.


Diesels are actually better with more heat in the engine. Our Tstats open at 180 and 185.

You sure? Thought it was 185\190 I could be wrong but I could a sworn that's what they say in dealer parts lookup

Either way I put two of the same ones whatever the higher one was
 

Hot COCOAL

May the farce be with you
Jun 9, 2012
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You sure? Thought it was 185\190 I could be wrong but I could a sworn that's what they say in dealer parts lookup

Either way I put two of the same ones whatever the higher one was

I installed new mishimoto t-stats when I replaced my engine. The old stock t-stats were 82*C (178*F) and 85*C (184*F)

The Mishimoto's were 85*C/88*C...
Mishimoto also offered a lower temp t-stat for warmer climates, it was lower than the stock set, but since I live in a fairly temperate and relatively "cold" climate I chose the higher temp ones...

Oddly enough, my truck now runs cooler than ever! I usually see ECT's around 190*F whereas before I never saw below 210*F

I don't know what to attribute that to, the Mishimoto T-stats or the Danville performance water pump???

FYI-
If your T-stats are still good, you can get just the rubber gasket ring.
 

Hot COCOAL

May the farce be with you
Jun 9, 2012
4,433
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Here's a pic of the old t-stats:
35c1ysm.jpg


The Mishimoto's I replaced them with (just the box w/part #):
dhbka8.jpg


And the replacement gasket:
70c9k1.jpg
 

OregonDMAX

NOT IN OREGON, NO DURAMAX
Apr 28, 2013
3,964
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Goodyear, AZ
I installed new mishimoto t-stats when I replaced my engine. The old stock t-stats were 82*C (178*F) and 85*C (184*F)

The Mishimoto's were 85*C/88*C...
Mishimoto also offered a lower temp t-stat for warmer climates, it was lower than the stock set, but since I live in a fairly temperate and relatively "cold" climate I chose the higher temp ones...

Oddly enough, my truck now runs cooler than ever! I usually see ECT's around 190*F whereas before I never saw below 210*F

I don't know what to attribute that to, the Mishimoto T-stats or the Danville performance water pump???

FYI-
If your T-stats are still good, you can get just the rubber gasket ring.

#1 this is America use feirenheight.
#2 always replace tstats if you are going far enough to change a tstat gasket, its simple Murphys law as soon as you go far to fix something it will break and need replacement
 
Oct 16, 2008
948
12
18
Idaho
#1 this is America use feirenheight.
#2 always replace tstats if you are going far enough to change a tstat gasket, its simple Murphys law as soon as you go far to fix something it will break and need replacement

Lol @ telling him to use feirenheight when you can't even properly spell Fahrenheit.
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,727
296
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Boise, ID, USA
#1 this is America use feirenheight.
#2 always replace tstats if you are going far enough to change a tstat gasket, its simple Murphys law as soon as you go far to fix something it will break and need replacement
#1 Fahrenheit is stupid and arbitrary. When dealing with mechanical/industrial/electronic systems, I highly prefer Celsius (or even Kelvin). Don't fear the future! Your engine is measured in Liters, the ECU works internally in metric, etc. The only time I prefer to see the temperature in Fahrenheit is for HVAC (climate control) systems.

I know what 72°F feels like, and I know how far 1 mile (and 1 km) is. But when someone says "go 440 yards" I have to stop and think for far too long to realize that is 1/4 mile. I can actually visualize 200 meters easier than 200 yards, because 200 meters is 0.2 km. 200 yards is 0.1136 miles, because reasons.

/angry young engineer rant at old and stupid measurement systems

#2 I would agree. No point draining out $10 worth of coolant to cheap out on $20 worth of thermostat.

I had the same issue on my truck, and new thermostats solved the problem. Getting 200k+ miles on a set of thermostats is pretty good, IMO.
 

OregonDMAX

NOT IN OREGON, NO DURAMAX
Apr 28, 2013
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Goodyear, AZ
Lol @ telling him to use feirenheight when you can't even properly spell Fahrenheit.

I never even looked it's whatever my phone spell checked it to, so blame andriod and blame me for being lazy biu I do know how to spell.

As far as using farenheight or celcius, our trucks temp gauges are measured in farenheight so why not use that...
 

malibu795

misspeelleerr
Apr 28, 2007
8,231
548
113
42
in the buckeye state
I simply installed a haydeen 2886 fan clutch in my LMM operating range is 81C-97C on long hills with high winddrage loads.. Norm its 81-88C.. Though I do have a big ass oil cooler
 

Hot COCOAL

May the farce be with you
Jun 9, 2012
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#1 this is America use feirenheight.
#2 always replace tstats if you are going far enough to change a tstat gasket, its simple Murphys law as soon as you go far to fix something it will break and need replacement

#1
Pay attention!
I did convert Celsius to Fahrenheit for the OEM parts in my statement (that you quoted)

#2
Both the OEM and aftermarket parts are labeled in Celsius (look at the pic that I also provided)....you're not going to get anywhere if you start asking around for a 186*F t-stat...it's America, the country that adopts, adapts and integrates the worlds standards into it's system-
Deal with it!

#3
I was only letting y'all know that the gasket was available by itself, I'm not one to cut corners on parts, or fluids. However some people don't like to replace things that don't "need" to be replaced. So "if" someone were so inclined to do so, they "could" just replace the gaskets on the t-stats. Removing the upper t-stat housing doesn't require $20 worth of coolant either...

:)
 

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,711
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Texas!!!
I don't think that's the seal he was talking about anyway. If that seal were to go bad, coolant would be leaking rather than bypassing the thermostat.
 

OregonDMAX

NOT IN OREGON, NO DURAMAX
Apr 28, 2013
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Coco my thermostats from GM were in *F only on thr package and they were listed in the parts database in *F only so you can throw that logic out the window.
 

Hot COCOAL

May the farce be with you
Jun 9, 2012
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35c1ysm.jpg



dhbka8.jpg




Well, I must be special then, cuz my stock t-stats are engraved with a Celsius temp (pics provided for reference), so are the aftermarket ones and when I called my local dealership they referred to them in Celsius as well...the ONLY thing that has anything in Fahrenheit is the temp gauge on the dash... that's just my experience tho
 

DAVe3283

Heavy & Slow
Sep 3, 2009
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Boise, ID, USA
Well, I must be special then, cuz my stock t-stats are engraved with a Celsius temp (pics provided for reference), so are the aftermarket ones and when I called my local dealership they referred to them in Celsius as well...the ONLY thing that has anything in Fahrenheit is the temp gauge on the dash... that's just my experience tho
Maybe we are just too close to the Canada border, eh?

It doesn't really matter. It comes down to what you are used to seeing. IMO, doing math/engineering is a bit easier with metric than American units, but the answer works out the same either way. I spend all day working with computers & electronics, and it is all °C here. If I had been working for years in °F, I would be more comfortable with that, I suppose. From what I have seen (in this industry, and in schools), the American units are dying out in favor of metric, because once you teach students both systems, the majority tend to prefer metric.

I personally like a weird hybrid. I want to swap my dash face at some point, so I will have the temperatures all in °C, but leave the speedometer in MPH. Again, just what I am used to seeing.
 

WolfLMM

Making Chips
Nov 21, 2006
4,005
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AL
Dave, I agree with everything you said. I've been working in thousandths for so long, I hate it when engineers and customers come in and reference everything in millimeters and microns. At least I know 1mm is .039 lol.