Thermostat setting

[M37UK]

Should the thermostat be slightly open when cold or should it form a tight seal?
As you can see here my one is open a little bit.
Thanks

thermostat.jpg (64.03 KiB) Viewed 2409 times

[T. Highway]

Stu,

Here is a picture of a thermostat that I have sitting in the spare parts cabinet. Amb room temp was 72 degrees F. It is completely closed.

Bert

[Carter]

I had one that would not completely close when cool and did not allow the cooling system to fully warm. Once replaced temps returned to normal operating range. I posted about this problem here on G741 a while back.

http://www.g741.org/PHPBB/viewtopic.php?f=2&t=3728

[M37UK]

I had one that would not completely close when cool and did not allow the cooling system to fully warm. Once replaced temps returned to normal operating range. I posted about this problem here on G741 a while back.

http://www.g741.org/PHPBB/viewtopic.php?f=2&t=3728

I guess I better order a replacement just to be safe.

Thanks guys

[MSeriesRebuild]

It is time to replace, that one is no good. Be sure you get a 180* replacement.

[M37UK]

It is time to replace, that one is no good. Be sure you get a 180* replacement.

Charles, why should I get a 180 instead of a 165 that came off the truck?
Does it help warm up the engine quicker or is there more to it?


Thanks

[MSeriesRebuild]

165* is too cold for an engine to run; does not burn off fuel by products sufficiently which will find their way into the oil causing early oil contamination. This simply creates issues that the additive package in the oil must deal with. Long story short, oil will become loaded with contaminents sooner drastically shortening its useful life. It has been well proven that the hotter an engine can run up to a point, the better .

[hbb]

165* is too cold for an engine to run; does not burn off fuel by products sufficiently which will find their way into the oil causing early oil contamination. This simply creates issues that the additive package in the oil must deal with. Long story short, oil will become loaded with contaminants sooner drastically shortening its useful life. It has been well proven that the hotter an engine can run up to a point, the better .

Adding to what Charles wrote a another advantage is by using a hotter tstat the engine will actually NOT over heat as quickly due to the fact it slows the coolant flow and allows the radiator to function at it peak performance, if there were no or reduced restriction in the coolant flow as in taking out the tstat out of the system the coolant would flow through the radiator so quickly it would not have a chance to transfer the heat from the coolant and as you drive it just gets hotter and hotter until boil over occurs and always us a good coolant at a 50/50 mix.So as you see a the correct thermostat has many functions to keep a engine running properly.

[M37UK]

Excellent, thanks for the heads up.

[Cal_Gary]

You'll appreciate the hotter thermostat if you run a cab heater as well.
Gary

[Sal]

What would a 165 Deg. thermostat be used for ?

Sal

[MSeriesRebuild]

160* range thermostats used to be the norm many years ago; with changes in fuel and oils plus much learning and new technology over the years has changed the program. Cummins is saying right now that the hotter an engine can run, the less the emissions that go out the stack. They are already using technology that allows an engine to operate at 215* with an amazing result. My how things have changed over time. I'm told as high as 230* in a "0" pressure system with the right coolant (EVANS coolant) is coming down the pike quickly.

[M37UK]

You'll appreciate the hotter thermostat if you run a cab heater as well.
Gary

Good point Gary, I do have a cab heater so the hotter temp should be better, thanks.

[hbb]

160* range thermostats used to be the norm many years ago; with changes in fuel and oils plus much learning and new technology over the years has changed the program. Cummins is saying right now that the hotter an engine can run, the less the emissions that go out the stack. They are already using technology that allows an engine to operate at 215* with an amazing result. My how things have changed over time. I'm told as high as 230* in a "0" pressure system with the right coolant (EVANS coolant) is coming down the pike quickly.

Charles GM has been there for several years with a standard operating temp of 228deg in many of their vehicles. The first of them was the Corvette in 1998 when they introduced the LS series engines and being here is Arizona it was quite a sell getting those customers to buy into the fact their engine was not over heating until it reached 240deg, A 1970 L88 would have melted down at those temps,but as you stated the technology that has come along is incredible.

hb

[ZGjethro]

I've been out of town so I am coming into this late. I replaced my sending unit and gauge this spring since they (one or both) did not work. The gauge starts off low, and quickly pegs at 260 I think. How do I trouble shoot which component is out of whack?