[seanrob]

After seeing all the posts in here about elevated running temps on the turbodiesels, just thought I'd mention one often overlooked item. My 82 300 TD had the same problem even after replacing the whole cooling system. I had finally given up and thought maybe it was just a slighty tired engine having to work harder or maybe a gremlin or two in the 20 year old wiring. That is until about a week ago when I was about to change my oil and I just happened to place my hand on the oil cooler and it was stone cold. And this was after driving it home from work in 85 degree weather. It was like an epiphany. "So this is the culprit", I thought to myself. Well, after replacing the oil cooler thermostat, which is located in the oil filter housing, my temp gauge is back down to where it is supposed to be, just above the 80 mark. I know that this is overlooked because my parts supplier said that he very rarely sells the thermostats. So people check those oil coolers, they too are part of the cooling system and they are there for a reason. If they are cool to the touch after driving the car hard, then they are not removing heat. By the way , I think the thermostat is fully open at 110 degrees (celsius I would think)

 

[Ler]

Part Number?

Hey seanrob,
Good call on the oil cooler! I checked yesterday after a drive and it was cold. Having a bit of trouble looking for the part though- do you have a part number for the thermostat?

 

[seanrob]

I think this is the correct part # 117 180 01 75Just a few words of advice though. C...

I think this is the correct part # 117 180 01 75

Just a few words of advice though. Check your oil cooler thoroughly, like on several occasions after running the car hard before just assuming that the thermostat is not working. I can say without a doubt that mine wasn't functioning ( I tested it after removing it), but you do need to be sure that it is not opening before you just up and replace for it is a nasty project if you DIY. Even after replacing mine I have checked it a couple of times and the cooler would be cold to the touch sometimes, and then other times it would feel very hot. So my point is this, don't just check it one time and then presume that the thermo needs replacing, check it over a period of time, preferably after sitting in traffic with the a/c on or after a flat out run on the highway to get the engine good and hot. If it is always cool and never hot then I think that it would be safe to say that you have a problem.