6.2 temp raising

[ssped]

I have always had this problem since got the truck a year ago. when climbing hills(normal driving freeway speeds) the temp raises. If I let it idle or cruise it cools off again. never gets to hot but gets up to the middle.

any ideas?

 

[85-m1028]

4 things take the truck to a radiator shop and have them inspect it, check the fan clutch for play, get a dual thermostat crossover and high flow water pump from peninsular diesel. <- do a search they have a website

 

[Can Can]

My 83 6.2 does the exact same thing, and has for about 20K, with no ill effects other than the odd boilover into the reserve tank. I'm willing to bet it's either a bad fan clutch, a plugged rad or something head related, but I'm not overly worried because it's been acting up like this for 4 years now.......

Is the motor using up coolant at all?

 

[tRustyK5]

"up to the middle" is pretty vague...

That describes pretty much what diesels do, they warm up when they work, and cool down a lot when under no load. Mid summer my thermostat won't open until i actually drive the truck...if it sits there idling the temp won't go above 140 or so. My thermostat may be stuck wide open though...

I'd get a good temp gauge to get a much better idea of what kind of temps it sees when working and when idling.

Rene

 

[ssped]

good idea. I really could just be doing what it is supposed to. I will grab a lazer from work and check her to see where she is actually running at. it usually runs at 1/4th on the guage durring normal driving but under load for a half a mile and the guage rises up to 1/2 way. I have never pushed it to see if she goes even higher but I do not want to push it. as far as useing coolant. I had to put close to but not quite a 1/2 gallon in after DD for 3 months. I would not say that she uses hardly any coolant. I ran a block test on the cooling system today and she totally passed. no change in color at all after 10 minutes of running.

 

[DieselDan]

Diesels are noted for not building heat unless they are "working", typically a high RPM long pull. Idling & low RPM cruising doesn't build any heat (see discussions on Diesel Slobber). So temperature swings are normal.

Mine would get pretty hot too when I first got it. The fan clutch seemed to be working (get it roasty warm then stop the truck and check for engagement). But the radiator looked like someone crapped in it. Finally I had it re-cored. Doesn't "over heat" now.

In perspective the "normal" operating range for coolant temperature on a military HMMWV is 190-230*

 

[ssped]

I drove her 700 miles this weekend including over the grapevine. she did warm up quite a lot when I pushed her but stayed steady in the hot(not red zone) while climbing. If I let off a bit and cruised a little slower she cooled back off. The radiator is new and I think she is working good after pushing her. after 300 miles there was some surging from the engine. I think it needs the fuel filters changed.

is there anything special(IE bleeding air out or priming the filters) about changing the fuel filters?

 

[85-m1028]

the surging is most likely coming from the fuel advance in the injection pump, usualy happen at higher revs??? there is an air bleed cap on the top of the filter holder, crack it open and crank it over till fuel spills out. usually helps to have a friend there to monitor the bleed valve and close it for you..

 

[ssped]

I changed the filters today and it was real easy. the surging is gone. It could have been an air leak or something. maybe even a clogged filter since I have not changed them since I picked up the truck.