Do you use an 87* thermostat in the winter?

[JDmills]

I just read a post the other day that talked about installing a 87 degree thermostat in their car.. which has gotten me thinking, that might be a good idea, as my car tends to get rather cold when it is going downhill in the winter, then it takes a long while to warm back up.. and I have swapped thermostats three times in the last year trying to find one that would keep it at 80* may be an 87* theromstat would allow me to take the cardboard off the radiator.. What do you think?? and do you change thermostats summer to winter depending on the season?

Originally Posted by JDmills

I just read a post the other day that talked about installing a 87 degree thermostat in their car.. which has gotten me thinking, that might be a good idea, as my car tends to get rather cold when it is going downhill in the winter, then it takes a long while to warm back up.. and I have swapped thermostats three times in the last year trying to find one that would keep it at 80* may be an 87* theromstat would allow me to take the cardboard off the radiator.. What do you think?? and do you change thermostats summer to winter depending on the season?

If it's not staying at 80C with an 80C thermostat, something is wrong. Mine will run at 80C in -10F weather, up or down hills. Do you have the correct OEM thermostat installed?

[larry perkins]

living in colorado i would think your hills are long,its a fact that if you dont burn enough fuel to create more heat than you lose then your temp will drop no matter what the thermostat is designed to operate at.
i have quite a few old diesels mb and a truck fleet,they all do the same,drop over a long grade without using up fuel (as in coasting) the temp drops in the engine even though the theromostat is in the warm up cycle. (radiator path closed and all coolant cycling thru the block).
just my opinion and experience
larry perkins lou ky

[larry perkins]

i am in the process of modifying my coolant system on a 87 300d to get a constant 190-210 f,(except down hills),so if you can find a source for a 87deg f thermostat please let me know.
i have exausted all my ideas on locating one.
larry perkins lou ky
ps
i dreamed last night about working on an muffler,
woke up totally exhausted.

[Cervan]

lol must have been a gas larry

[toomany MBZ]

Originally Posted by Craig

If it's not staying at 80C with an 80C thermostat, something is wrong. Mine will run at 80C in -10F weather, up or down hills. Do you have the correct OEM thermostat installed?

Agreed, folks in mountainous regions may have difficulties, but swapping out t'stats per season is a bit excessive. And certainly will not heat up an engine that has lost energy via down hill "coasts".

Originally Posted by toomany MBZ

Agreed, folks in mountainous regions may have difficulties, but swapping out t'stats per season is a bit excessive. And certainly will not heat up an engine that has lost energy via down hill "coasts".

That was my point, if the thermostat fully closes at 80C (as designed) and the engine continues to cool (mine has never actually done that), having a 87C thermostat won't really help. The only thing it would do is force the engine to run too hot all the time so it would take a little more time to cool, not a good trade off IMHO. I would start by installing a 80C OEM (not McParts brand) thermostat.

[SD Blue]

[QUOTE=JDmills;1708132]........... as my car tends to get rather cold when it is going downhill in the winter, then it takes a long while to warm back up.. QUOTE]

This sounds like an aux. water pump not working correctly.

[larry perkins]

guys,i have a friend who worked for cummings,he ran the test dept,he says that one should run a diesel at 192 degf to get the best performance.( his advise)
i think most of us run the engines too cool.
larry perkins

[fj bertrand]

cardboard. Radiator block. works well.

Originally Posted by larry perkins

guys,i have a friend who worked for cummings,he ran the test dept,he says that one should run a diesel at 192 degf to get the best performance.( his advise)
i think most of us run the engines too cool.
larry perkins

If I ever buy a cummings, I'll be sure to run it at 192F (89C), in the mean time, my car will run at 80C, as designed.

If you engine is cooling below the thermostat setting, something is not correct and should be fixed. These engines do not need cardboard in front of the radiator or the incorrect thermostat installed. Most folks eventually find that the installed thermostat is not working correctly (even if they've already replaced it).

[babymog]

It's CUMMINS.

The engine will continue to cool below the closed-thermostat temperature if you're using more heat at the heater than the engine has available. Cold weather and an idling diesel don't mix well, especially on the freeway.

I can't think of much that you can do about it other than turning off the heater for the descent, gotta burn more fuel. It should heat up again fairly quickly though.

Originally Posted by babymog

It's CUMMINS.

Some kind of truck, I suppose?

[JDmills]

Originally Posted by SD Blue

This sounds like an aux. water pump not working correctly.

Is this the one that sends coolant to the heater core?? If not, what is the auxulary water pump??



And Yes I have a problem, as I Have put three thermostats in the car, and none of them will keep it at 80*.. but they open at 80* in a can of hot water... SO.. I put cardboard in front of the radiator, which help, but even with a strip of 2'' of radiator showing, and the oil cooler as well, the car takes all of 6-7 miles to get to 80* once there it will drop tempature on any down hill I am on.. back to about 60* so now i drive to work with the heater blower on low, and enjoy walking in to the building for obvious reasons..

Originally Posted by JDmills

Is this the one that sends coolant to the heater core?? If not, what is the auxulary water pump??



And Yes I have a problem, as I Have put three thermostats in the car, and none of them will keep it at 80*.. but they open at 80* in a can of hot water... SO.. I put cardboard in front of the radiator, which help, but even with a strip of 2'' of radiator showing, and the oil cooler as well, the car takes all of 6-7 miles to get to 80* once there it will drop tempature on any down hill I am on.. back to about 60* so now i drive to work with the heater blower on low, and enjoy walking in to the building for obvious reasons..

The auxiliary pump is the little electric pump that sends coolant to the heater core at idle. That's not your problem if the actual engine coolant temperature is that low.

Just out of curiosity, what brand thermostats have you put in the car?

No offense, but when I first got my car and it was running too cold, I found the thermostat installed backwards.