Engine/Transmission (1998.5 - 2002) Engine oil temperature - how high is too high?

[TomGolden]

Howdy all,



I recently drove down to the Mjoave desert of southern California to spend July 4th with my folks. I drove 450 miles down through the central valley of CA, and the temps were fairly warm the entire trip. I have an engine oil temp SPA gauge, and it got pretty hot and stayed there for most of the trip, which got me to wondering what the safe range is. I'm specifically interested in engine oil / coolant temps here.



Specific details:



* Engine oil temp gauge sending unit is in the second port on top of stock oil filter unit.

* Outside air temps were anywhere from 95* - 107* F.

* Engine oil temp on SPA gauge read anywhere from 198* - 207* F for entire trip.

* Factory engine coolant gauge stayed about 1 needle width above the 190* mark, never more than that.

* I have a 190* thermostat, new at ~16K miles ago.

* Truck has 66K miles, I change coolant every 25K, use Fleetguard PG based Complete 50/50 pre-mix coolant.

* I was completely empty, no load in truck bed, not towing anything. Slight headwind, average vehicle speed was 75 MPH.

* EGT temps were between 750* - 950* entire trip.

* I run Amsoil series 2000 15W-40 HDD&M full synthyetic oil in the engine. Change oil at 10K intervals, filters at 5K intervals. Current engine oil has ~9K miles on it, will be changed later this month.



I suppose this isn't anything to get worked up about, but it got me to thinking that I should find out what the safe temperature limits are so I'll know if I ever do get close to the danger level.



Thanks all,

Tom

 

[JJW_ND]

Oil temps just fine!

Those temps are just fine Tom. I was told a while back by Cummins that the oil temp should run 15 degrees or so warmer them coolant temp. They also said to keep oil temps under 220 if possible. Anything under 220 was just fine.



Better to have oil temps in the 200 range then the 170 - 180 I fight with most of the winter up here.



I have had a temp guage in mine for most of its life. When I pulled trailers back in the summer heat I would sit on 220 the entire 700 miles. Oil analysis was always better in the summer then the winter.



jjw

ND

 

[RowJ]

With a good quality synthetic oil-like your Amsoil, you are perfectly safe with sustained temps as high as 250 degrees F. It can handle short periods up to 300 degrees. When it cools down-will look like new. Oil change interval of 10,000 miles in good safe level, as long as not doing heavy towing. Save your money on the filter change at 5,000. Use a good filter, (Amsoil or Baldwin are two excellent brands) and leave it for life of the oil. To be certain, do an oil analysis once or twice to confirm this fact.

 

[TomGolden]

Thanks guys, since I had not had the engine oil temp gauge on long enough to get previous experience in high outside air temps, I didn't have a baseline for what is normal, and I got a little worried.



I do use the Amsoil oil filters (SDF-80), single full flow filter only, might do a dual bypass filter setup some day...



I also do oil analysis every 5K miles, whether it is oil change time or just oil filter change time. Have done this from day 1 of the truck's life, always comes back with outstanding results.



Thanks again,

Tom

 

[Dkevdog]

I regularly and routinely see temps of 210* from my gauge, mounted in the same spot.



Funny thing is, it runs that temp almost always, towing or ambient temps don't seem to effect it too much .



Kev

 

[Josparkz]

My Amsoil 15W40 runs between 175* and 200* . The 200* is when she's warming up a bit, water temp 190* or so , and pulling a hill or stuck in traffic w/90*+ ambient temps .