I replaced my oil cooler a few weeks ago, and noticed its running warmer by 10 degrees or so now.

When driving around, my oil temp gauge reads 240 +/- a few degrees.

I know this is HOT, but safe is below 250 if I read is correct.

Here are a few questions; for now and for future reference!

1. What is normal operating oil temperature?
2. What is normal operating oil pressure @ idle and load?
3. What is normal operating coolant/engine temperature?

What could be causing my oil temp to be so high? The location of the capillary tube for the gauge is at the bottom of the oil pan near the oil level sensor. Could this be giving me the wrong reading? If so, where would be the best place to get a more accurate reading?

Thanks in advance for the help!
Chris

 

Hottest I have ever seen was 185*F on track in July. I get my temps from the oil
pedestal block and autometer gauges.

Is your thermostat opening?

 

I would presume my thermostat is opening. I just replaced it when I did the oil cooler.

The oil pedestal block; right below the filter next to the engine temp sending unit? Doesn't RB have a nice adapter plate for that?

 

I will almost bet that the thermal bypass valve is either missing, installed incorrectly, or stuck in the oil cooler. This would make the oil flow straight through the oil cooler lines totally bypassing the oil cooler.

 

Is that the valve at the bottom of the cooler then? Is there any way to test it?

Would the current location of cap tube at the bottom of the oil pan give me a different reading than what I need?

 

It should give you a close enough reading. Like the others I have my sensor in the filter pedastal (using the Re-speed pedastal) and the highest I've ever seen is just shy of 200, on both my 12a FB running A/C as well as my T2 powered FB....
I'll vote for the bypass valve being stuck as well, although i'm not sure how you'd test it, maybe like a thermostat in a pan of boilng water and see at what temp it actually opens...
Oh and yes its the valve/thermostat on the bottom of the oil cooler

 

That's what it is called! I always called it the oil thermostat. Oops

 

My oil temp generally runs around 160, 165 degrees. Long hard runs on really hot days will sometimes get it up around 175.

 

What brand/model of oil temp gauge are you guys running? I have iEquus electrical (oil pres, water temp, volts) gauges but they don't make an oil temp. I called iEquus and they said a water temp would work for the oil temp.

I checked out the autometer but they wanted $200 for the electrical oil temp.

 

I use an autometer mini "auto-gage" electrical water temp gauge in the console, with the sender in an RB type II gauge block:





Middle gauge is oil temp; normal position is pretty much right on or just below the line between yellow and green.

Temperature is temperature; doesn't matter if it's measuring water or oil, so long as the sender will tolerate the pressure - - normally not an issue.

.

 

So Divin, you're using an electrical sending unit for the oil temp rather than a cap tube? My current setup is a Stewart Warner mechanical gauge. Maybe I should just order an electrical gauge with the sending unit and the RE-Speed or Racing Beat oil pedestal.

I'm half tempted to say my gauge may be bad. It seems to go up extremely quick. I start the car and the needle almost immediately starts going higher.

I'm on vacation until Sunday, so I will have to check out the gauge on Monday.

Thanks for all the info so far, its really helping!

 

General consensus usually is that mech guages are more accurate, and can respond faster, but I found the installation convenience of electrical to tip the scales for me. Cap tubes being fragile & complex of routing.

 

I run an oil temp gauge in the same location on my oil filter adapter. My oil temps generally stay between 150 and 180. 180 being after a hard pull from 1rst thru 3rd. There is a write up on FC3S.org on how to mod the thermal bypass and let the oil flow through the oil cooler all the time. The purpose of the thermal bypass is to let the oil in the engine warm up faster by bypassing the cooler untill it reaches about 150*.
http://fc3spro.com/TECH/MODS/mods.html

 

110* back to back 60 second autoX runs with no cool down and my oil temps didn't get above 190*F. something is wrong. I shut down the car at 210 god forbid it ever got that high.

 

It also insures that the oil does not run too cool. It needs to get hot enough to allow moisture to evaporate, if you disable the thermal valve then I would be concerned that it would not get warm enough to accomplish this.

 

Now that I am back from vacation, I started to look into it.

My gauge starts at 140, yet the needle starts at 175 for some reason.

The 35 degree difference would put me at roughly 205 degrees, which is better than the 240 it actually reads. Is this bad logic, oh hell yeah.

So, when the next paycheck comes in, I will be ordering new stewart warner or autometer gauges along with the RB or RE-Speed oil adapter. I will be switching to electrical gauges for ease of installation.

Nothing like spending $200+ on tires and $400ish for a carb one day for one rx7, then spending another $250+ on gauges and the adapter. Maybe I should sell one of them, haha.

I now understand why people say they have so much money invested into their 7s.

 

mechanical gauges are lame, show me a car newer than my 1958 Tr3 that uses them...

divin; its too bad your little gauge goes to 280, be a little easier if it only went to 230-240 or so, you'd get more than 1 hash mark between 150 and 190.... not like it needs it, but it would be nice