Engine/Transmission (1998.5 - 2002) Engine oil temp is too hot, WHY??

[motobret]

I have been having a problem w/ my oil temp getting hotter over the past few months. It used to run about 225 degrees, now it is over 260 degrees.

I have changed oil, filter, swapped out temp gauge & sending unit, to no avail. Oil pressure is around 40-50 lbs.

The water temp stays constant at 180-190 degrees. Boost is under 30psi & exhaust temps are under 1200 pre & 900 post turbo. It does not appear to be related to RPM, but does get worse as vehicle speed increases. Heat is the worst at highway speeds. I am thinking maybe I have a blocked oil passage, but would like to hear any suggestions, possible causes, and/or fixes.

Thank you

Brett

 

[WestTN]

Where is the sensor installed? Who made it? Since these engines have a water to oil cooler built in, the oil temp should never be that far above the water temp. From the description of oil flow in the service manual I can't see how the oil cooler would get bypassed. maybe this needs to be checked at a Cummins shop.



Have you checked your oil level in the engine? if it is very high for any reason the oil could be getting whipped up by the crankshaft. At higher speeds this might cause oil heating.

 

[motobret]

The sending unit is on the filter housing, and I have used 2 different brand gauges & sending units, both showed close to same temps. The oil level is good. Talked w/ Dodge mechanic, he doesn't have a clue want could be wrong. Might end up at the Cummins shop.

 

[MKoth]

Are you 100% sure the water temp gauge is reading correctly?

 

[DennyDay]

Check the radiator - - - if you still have the breather bottle, that bleed oil maybe fowling the radiator with oil causing the road trash to stick to the radiator.



Denny

 

[motobret]

I have thought about it (water temp), but i don't have any leaks, drained & flushed system this summer w/ no signs of oil or any other problems with the cooling system. Just to make sure, I think I will order a mechanical water temp gauge, and see exactly what I get for water temp.

 

[Mundgyver]

Oil temp in your motor should only be about 10 to 15 degrees above your water temp. This of course is running unloaded. My water temp runs about 186 and my oil temp runs at 195 to 200.



You might want to pull an oil analysis real quick and see what your metals look like. If you have a blocked or partialy blocked journal then you would be in a starvation mode which would show up as a spike in your metal traces in the oil.



The hottest that I have ever seen my oil get to is 245 at 23,000 lbs GVW on an 8% uphill grade for 6. 3 miles. Water was around 215.

 

[motobret]

Thanks, the oil analysis is an excellent idea.