high oil temps in Autumn

[Fleetwood]

Just finished relocating my 79 SC south to Salt Lake City for some winter improvements. Oil cooling system is stock with a loop in the fender and leading this years list is a radiator and fan to replace the loop.


This trip, oil temps topped out just a tiny bit under 250 before I slowed up to the low 80's and saw the temp go down to 220-230 as long as no hills were present. Outside temp was mostly in the low 70s, so I was quite surprised to see the oil temps this high. A little past operation in Utah, when its well over 90, have seen the temps climb nearly this high but even a track day at Miller in the spring (outside temp in the 70s) didn't get me past about 225. No worries on track running at full tilt for 20-30 min sessions...why the higher temps with moderate, say 90mph continuous operation? I felt like I could watch the oil temp rise and fall based on elevation changes and the fact that I had to slow down to the legal limit several times to preempt increases above 240 spoiled much of the thrill



I've owned this beauty for over 30 years with nearly all of its time spent in Washington state. Last years Utah trip, in October, was measurably slower with no elevated oil temps in similar outside temps.* Engine rebuilt and improved to 3.2 (209 RWHP) about 12 yrs ago by PCA technical advisor for SC's/Carreras, Chris Powell. Never a temp issue up north.


A couple of "episodes" on this trip had the oil temp nearing 250, then dropping significantly to 220-230 for a moment, then resuming its climb up until I moderated the speed or found a downhill to reduce the load.


Over the years I've had mouse house issues on top of the engine. These were quickly recognized by elevated gauge temps, from the normal 180 to 190 or so for low speed operation. A quick view into spark plug holes and thru the fan show no evidence plus the temp gauge was never elevated thru the whole summer of driving up north.


Looking for input and counsel from the group. My absolutely wonderful drive was slightly compromised by concern over the high temps.* Thanks ahead

[David Inc.]

Did your oil coolers get hot? Sounds like a stuck thermostat.

[pampadori]

mine runs much hotter at 90mph than at 65mph too. Its quite noticeable. I too only have the trombone cooler.

[stevie 77 930]

Recently, I changed my spark plugs and i didn't notice the i was sent was a set of "hotter" plugs than prior installed. I instantly noticed higher than normal oil temps even on a short trip.
This was immediately resolved with a new set of plugs.
Be sure your spark plugs are in the correct heat range.

[RSTarga]

The loop cooler was marginal on the 2.4, certainly not adequate for sustained high speed on anything larger displacement.

[Nditiz1]

My 3.0 in the hottest summer runs 210 all day. It did run a little hotter 220 on a long trip 100 degree ambient, but after SSI I haven't seen it go over 210

[pampadori]

Um, no a hotter spark plug didn't cause your oil temps to be higher. Come on you all.

[winders]

The lower the barometric pressure, the less effective air-cooling becomes. A loop cooler may not be enough. You will probably want a fin cooler. The fan is less effective at altitude so the heads and cylinders will run hotter too. So the engine runs hotter and the oil is harder to cool….