Oil temps

[Mike Thompson]

I'm going to install an oil temp sender in my car. I've never done a detailed analysis of the temp gradients, but it would seem the oil is hottest on the cylinder walls, and coolest in the pan. Where do the big boys (racers) put their sender to get the best useful temp reading? I could drop the pan and drill and tap into it, or, as someone said, take the temp off the oil pressure sender tap. Not sure that reflects accurate temps, but where would?????
Mike

 

[KW]

I think the oil pan would be the best place for it. That is where the oil is picked up from and where the oil is returning to. And after everything is up to operating temp the bulk of the oil is heat soaked.

 

[XS650]

#1`The pan, #2 and not so bad, the main oil gallery before it has gone too far in the block.

The vast majority of reported oil temps are pan (sump) temps and you will be able to compare you results with others far better that way.

 

[Mike Thompson]

Well that pan would be much simpler, but its aluminum and I would think it would be cooling the oil off fairly quickly. On the other hand, since my pump puts out over 12 gpm (6 cyl) at speed, a 5 qt. sump would be changed every 6 sec. I suppose not much cooling happens in this interval. Of course my Mobil 1 filter probably cuts this flow significantly

Mike

 

[ALS]

In my Volvo the Factory oil temp sender replaces the drain plug in the pan. It just has a spade connector that you plug the wire into.

 

[Jeffrey Behr]

quote:

---

Originally posted by Mike Thompson:
...take the temp off the oil pressure sender tap.

---

That's NOT a good idea, as there's no oil FLOW there, just pressure. The sump/pan is best, but measuring the temp in a full-flow outboard loop would be fine too; realize that the oil after the oilpump will be a little hotter than it was in the pan.

 

[TallPaul]

I wonder if a fitting is made to screw on between the block and filter, maybe 3/4-inch thick, that has a tap for an oil temp sender? I suppose a good machine shop could fabricate such a fitting.

 

[Gary Allan]

Unless you've got a factory designed location ..the pan gets my vote. Anywhere in the head or block will have too much influence from the water jacket. I did this on a Ford 2.3 and the oil temp always tracked the water temp. The pan will at least give you an idea of "oil temp insult reserve" so to speak and give you some idea of how you're heat fatiguing it.

I'll probably use a tap off of my remote mounts when I finally get around to this myself.

 

[ZR2RANDO]

The oil pan is also not under pressure, less chance for leaks.

 

[DEWFPO]

The oil temp gauge on our Audi must me in the oil pan since the oil cools off very quickly on winter days after just a very short shut down. Even so, the oil tmep (in the pan) gets up to 250 degrees on long uphill grades with both turbos blowing at 3,500 rpm. Makes you wonder how hot the oil really gets in some spots.

DEWFPO

 

[Mike Thompson]

quote:

---

Originally posted by ZR2RANDO:
The oil pan is also not under pressure, less chance for leaks.

---

Now that is an excellent reason to go for the pan!!!
Mike