PiB993

My OBDII reader indicated my cars "coolant" was at 264F (198c) when my p1140 went off. That's HOT by most oil temp standards? Not sure where I've been on the instrument gauge. P1140 seemed to have been cured by a throttle position sensor then finally went off again after a few months. 3000 mile oil analysis also came back "this oil has seen some heat" comment.

Is the oil cooling about the same as the non-turbo 993's? I'm looking at the following parts:

1. Oil cooling Fan Relay.
2. Oil temperature sensor.
3. Oil Thermostat.

I'll be watching the temp gauge more closely now.

OverBoosted28

Apparently, you're a bit more relaxed than I am. I am constantly scanning and checking my gauges, noises, smells....... :-)

PiB993

I do scan my gauges and if they are in the red I would be alarmed but if the temp gauge was just beyond 9 o'clock I would not have been concerned. I guess I should be.

OverBoosted28

I have only had my temp gauge go just above 9 o-clock at the track on a warm day. My thermostat won't open till it's close or just at 9 o-clock. Only then will that "awesome" oil level gauge start to move.

Basal Skull

I'm not sure what that obdII temp is actually reading. Is it head temps? I know when I'm logging data though the OBDII, there's one temp that actually goes so high it stops reading. Most temp sensor max reading is 300F. My Durametric might tell me, I'll check it next time I have it hooked up.

Kein_Ersatz

Well is there more then one oil temp sensor?

There is:

• the intercooler sensor 993 606 114 00 used for ignition ECU input (air temp?)
• the remote temp sensor 911 606 113 00 I assume air temp
• the remote temp sensor 993 606 113 00 cyl head #3 engine temperature to ECU
• the catalytic sensor 993 617 119 which I assume is emissions
• the oil cooler sensor 964 624 110 00 which I assume is for the fan control
• the oil temp sensor 993 606 012 00 which I assume drives the gauge

Those are the only hits in the PET for temperature sensors. So I would assume gauge "value" is oil temp reading. Would not think fan relay oil temp is sent anywhere but the fan controller. But is the gauge temp sensor what the OBD III is showing, good question?

PiB993

That crossed our mind here too is where the temp is measured BUT the oil analysis did mention the heat. Never had that comment before and other content levels in the oil where all okay.

Quadcammer

that may be head temp.

264 oil temp would be basically in the red.

my car, under normal conditions, does not exceed 200degrees f.

OverBoosted28

^^^^ agree with Quad, the chance that it's actually oil temp. is low. I may be mistaken but without knowing what which sensor the scanner was using/reading, I'm not sure that value can be of concern. The only other factor to show it may be oil temp. is your analysis which showed heat. I would still be all over it until you're sure it's NOT boiling oil. Good luck and keep us posted.

JasonAndreas

The only temperature inputs to the M2.1 and M5.2 ECU (according to the wiring diagrams) are intake and CHT.

PiB993

What is CHT?

More confusion:

286F reading:





But gauge reads:





(Well under 9 o'clock)

I think I can hear oil being pumped to the front rad but no fan. When cruising economically where should I keep the rpm? At 3000 I could keep the temp reading much lower - around 255F. Outside temp for all this was 45-55f at night.

Quadcammer

CHT=cylinder head temp

I'm relatively certain that coolant number is actually your head temp, and I don't think 286 is cause for concern.

Your gauges look normal. fwiw, if your oil was at 286, your oil pressure would likely be much lower.

Dick in TN

The '65 Corvair Corsa Turbo has a cylinder head temp. gauge in the dash and 400F is the midpoint if I remember correctly.
Just a bit of trivia for the body of knowledge.

JB 911

I agree with the others that that is most likely your head temp and not reason for concern.

You might want to add oil fan resistor to this list. In fact I would start with it. Bruce7 did a fantastic write up that shows you how to check both your oil fan and ac condenser fan resistors which both are a known weak point. Once failed, your oil fan will not turn on until the high temperature is reached - not good. With the ac fan resistor failed same thing. The ac condenser fan will cycle between off and high fan setting which forces the system to run at a higher pressure than if the low speed setting was present. The ac will still work fine but there is another known weak point in the ac system and it costs considerably more than a new fan resistor

https://rennlist.com/forums/993-foru...resistors.html


This sounds like normal operation and that your low speed fan is functioning. According to this link on p-car.com, once a 993 oil temp hits 230F the low speed fan should kick in and hold the temperature where you indicated.

http://p-car.com/diy/fan/

However one thing I noted is that while driving on hot days, as long as you are moving, the oil temperature stays around 200-210 and the fan stays off. But just 5 minutes idling or going thru a few lights and my fan starts cycling between low and off keeping the oil around 230. I think the consensus is while not too hot, this is perhaps unnecessarily hot and someone? invented the manual override that lets you force the fan on in this situation. Here is the link to that mod which I will be doing before this summer hits. I think 230 is ok once in a while and for short periods, but if you get stuck in traffic or have to stay at 230 for an extended period, it would be really nice to push a button and lower your oil temp 20-30 degrees.

http://www.pcarworkshop.com/index.ph...verride_Switch