Oil Temp

[acmjg]

I know this has been discussed before, but I just installed an oil temp gauge and it reads from 140*F to 320*F. The needle barely gets to the 140 mark during spirited driving. Looks like its not even working. My water temp is about 190F. I do have an oil cooler. I have done the boiling water test and the sensor is good. Is this OK?

Thx,
Anthony

[DAVID GAGNARD]

No................You want your oil temp at least the same as your water temp.........you need to block off some of the airflow going to your oil cooler to get your oil temp up...........

David

[Bobcat]

David is correct . Too low a temp will cause premature wear in your engine . I went with a Canton oil thermostat and my oil temps are in the 180 to 190 degree range in normal driving and go to 200 + when I run it hard .

[DAVID GAGNARD]

A easy "trick" that will go almost unseen is to take some of that wide,clear packing tape and put a piece across the bottom of the cooler fins and try the car,keep adding tape to block off the airflow till you get your oil temp where you want it.....
anything bewteen 180 and 220 is good....
on my race car with an oil cooler, I just use duct tape on those days when the outside air temp is below about 60 degrees, pretty much anything above that, it needs no tape to keep the oil temp in the desired range.

Cool/cold oil doesn't flow thru the engine well, and doesn't lubricate as well as hot oil.......

David

[dcdoug]

What was the outside air temp when you were driving it?

[acmjg]

OAT was in the mid 70's F.

[acmjg]

Originally Posted by DAVID GAGNARD

A easy "trick" that will go almost unseen is to take some of that wide,clear packing tape and put a piece across the bottom of the cooler fins and try the car,keep adding tape to block off the airflow till you get your oil temp where you want it.....
anything bewteen 180 and 220 is good....
on my race car with an oil cooler, I just use duct tape on those days when the outside air temp is below about 60 degrees, pretty much anything above that, it needs no tape to keep the oil temp in the desired range.

Cool/cold oil doesn't flow thru the engine well, and doesn't lubricate as well as hot oil.......

David

I'll try that trick with the tape. That little cooler must be pretty effective. Thanks.

[dcdoug]

You sure your gauge is reading right? Even with an oil cooler at 70 degrees OAT, you should be well over 140 degrees after driving it for a while.

[twobjshelbys]

Some have installed a oil cooler thermostatic bypass. You can find them on Jegs and Summit. Others have bypassed the cooler altogether.

I found the same to be true of the water temp. The radiators (both water and oil) are efficient, or perhaps oversized for street driving. I've gone from a 160* to 180* thermostat. It still cycles at the thermostat temp.

[jhv48]

Perhaps a dumb question, but where did you install the temp sensor? Is it measuring the oil in the pan, the oil filter, or perhaps the oil line after the oil is leaving the oil cooler?
No way is that engine running 140 degrees on a 70 degree day under spirited driving.

[acmjg]

Jim,

Temp sensor is in the front of the oil pan sump.

[bobcowan]

Oil is predominantly heated by rpm's. Consistantly high rpm's will heat up the oil like it should. A few rapid accelerations on the street aren't enough to get it really hot.

After a while, the oil temp generally stabilizes at around water temp.

If you have an oil cooler on a street car, your oil will never get hot. Unless you're driving in Phoenix in July.

If you must have an oil cooler on the street, then you really need a thermostat. When fully closed, it will allow about 10% of the oil to flow though the cooler. That allows all of the oil to warm up at the same rate. On a cold day, like 35-40*, the oil still will not warm up; even with duct tape covering the core.

I installed a second external electric oil pump that feeds the cooler only. When it's cold, I leave the pump off, and the oil warms up just like a DD would. On the track I run the pump all the time.

There are two down sides to this set up: First, the electric pump doesn't flow as much volume as the standard oil pump. The oil tends to get about 15-20* hotter than it used to. Not a big deal, since I use Royal Purple.

Second, if the oil starts getting hot, you can't just flip the switch and run the pump. That will inject a big slug of cold oil into the system. And that's a bad thing.

[twobjshelbys]

Comments in color embedded in the quote.

Originally Posted by bobcowan

Oil is predominantly heated by rpm's. Consistantly high rpm's will heat up the oil like it should. A few rapid accelerations on the street aren't enough to get it really hot.

After a while, the oil temp generally stabilizes at around water temp.

I concur with both observations above. Driving around town won't do it. Get it on the freeway and oil temp == water temp. But it won't happen until the engine runs above 3000RPM for a while. From starting my water temp gets to operating in about 5 minutes; in stop and go oil will catch up in about 15-20. Mine is a Roush 427 and the oil temp sensor is in the pan.

If you have an oil cooler on a street car, your oil will never get hot. Unless you're driving in Phoenix in July.
It will warm up (as does water) in stop and go traffic, but like above, tends to equalize to water.

[DAVID GAGNARD]

Another question or two: what type oil pan and what is your total oil capacity of the whole system????? my race car set-up holds 11.5 quarts total, take a while to get the oil temp up.....

For example, my street car has done some track time so I have an 8 quart Canton road race pan, 325hp,351-W,NO oil cooler.....The other day I went to town and ran errands in it,probably 2.5 miles on the highway to town, ran around town for maybe 20 to 30 minutes total, making a few stops here and there and then back home.....During the course of this time, I ran it up to 5000rpms in 1-2-3 gears a few times...when I got home my oil temp had just hit 170!!!!!!!!!!

If you get on the road and run it thru the gears a couple of times and then cruise around at low rpms, then head home with less than 30 minutes of run time, you probably will never see much over 150/160 on your oil temp gauge....
If I get on the highway and head out,it does take quite a while at cruising speed for the oil to stabalize at 180 (I'm guessing up to 20 minutes,depending on outside air temp), which is what it normally runs under normal conditions..........

David

[jhv48]

Is the sensor installed well below the oil level in the pan and far enough into the pan to be fully immersed in oil?

[DAVID GAGNARD]

Originally Posted by jhv48

Is the sensor installed well below the oil level in the pan and far enough into the pan to be fully immersed in oil?

That and be sure to check the routing of the capillary line, you want gentle bends,no sharp turns or kinks, if you accidently kink the line,throw away the gauge, cause if will most definetly be off...........

David

[acmjg]

Pan is a custom made road race "T" style pan and holds 7 qts. Sensor is mounted 1" above the bottom of the pan on the front side. Most definitely in the oil. Gauge is an electric Strewart Warner.

I'll do another calibration test with boiling water to confirm the proper operation.

[jhv48]

Make sure the sensor extends all the way into the oil and isn't touching the metal pan, thus measuring the temp of the oil pan instead of the oil. And yes, this has happened before. The bung in the oil pan may not be letting the sensor extend fully into the oil to get an accurate read. When you remove the sensor again, stick a bent paper clip into the hole and hook it on the inner lip of the bung. Then measure the length of the bung and compare it to the length of the sensor. The sensor must extend beyond the bung in order to accurately measure the oil temp.
Don't worry. Your engine is running warmer than 140. It's either a faulty sensor or faulty placement. If you have a remote oil filter, you can try mounting the sensor there temporarily for a comparison.

[twobjshelbys]

Originally Posted by jhv48

Make sure the sensor extends all the way into the oil and isn't touching the metal pan, thus measuring the temp of the oil pan instead of the oil. And yes, this has happened before. The bung in the oil pan may not be letting the sensor extend fully into the oil to get an accurate read. When you remove the sensor again, stick a bent paper clip into the hole and hook it on the inner lip of the bung. Then measure the length of the bung and compare it to the length of the sensor. The sensor must extend beyond the bung in order to accurately measure the oil temp.
Don't worry. Your engine is running warmer than 140. It's either a faulty sensor or faulty placement. If you have a remote oil filter, you can try mounting the sensor there temporarily for a comparison.

Hmmm, maybe something valid here. If the sensor isn't going through far enough then the initial temperature is waiting for the mass of the pan itself to get to temperature. That lag could be significant. Makes sense. I'll look at it next time I change the oil.

[mln385]

This is what happened to me, the dealer provided bushing did not allow the sensor into the pan thus I had no oil temp reading from day one. Changed out bushing to a shollower one allowing the sensor to get into the oil and now I have a temp reading.