3.6L conversion question re:oil sender

[mnmasotto]

I installed a 1995 993 motor into my 1987 Carrera last year. I have been dealing with high temps ever since. I currently have a "Wide Mouth" Carrera oil cooler in each front fender. I upgraded the stock Carrera fan to a high output unit and a adjustable thermostat sold by ER on the passenger side oil cooler. I set the thermostat at 190F. I also have the new finned ER oil lines. I have yet to install a fan on the drivers side oil cooler.

1) I am certain the fan turns on as it should. 2) Both oil coolers and oil lines get very hot to touch. 3) I removed the fog lamps to allow more air into the oil coolers.

When driving, the car appears to warm up in the normal allotted time. However, the car temp appears to creep up to 240F fairly quickly, especially after an spirited driving especially if the A/C is on. The car will sometimes creep up to 250F but seems to go back down to 240F in a few minutes of easy driving. I am in Southern Ca and my driving is usually in the low to mid 80 degree weather. I am currently using 20-50W Brad Penn oil. The motor was just rebuilt so I am certain there are no rats nests or debri under the fan shroud.

The motor has the stock 993 oil temp sender and I am using my stock Carrera oil temp gauge with a painted screen (numbered). Could this be an issue with the 993 oil temp sender not being compatible with the Carrera gauge?? Please help I am at my witts end!

P.S. I have read more posts on this subject over the past two weeks but I can't seem to find what I need.

[DW SD]

I suspect your external thermostat, but it could be your sender / gauge compatibility. I have the same engine, but only one cooler 72 row front mounted setrab - 16 lines from ER finned lines. I have no cooling fan, either, but also avoid traffic.

My temp pretty pegs at 210 to 215 degrees, which I've calibrated and established is where the thermostat opens. I'd do this to test: Have a friend run the engine at 2k to 2500 rpm. Get out a garden hose and gently run water over one of the coolers. The water should remove enough heat to establish at what temperature your thermostat opens / closes. What does the gauge read?

A second test to test your gauge / sender is to remove the sender, use some 5' sections of wire with alligator clips to extend the reach of the sender and drop the sender in a pan of boiling water. Make sure to ground the sender body with one of the extension leads. This should read about 212 F. I might propose doing this test first to verify callibration of your gauge.

Note, I have read that the Porsche external thermostat is supposed to open at 190 F. Mine opens about 210. I'm not sure why. It was brand new when I installed it and discussed with Chuck at ER about its operation. He assured me it was working properly.

Finally, I've devised another test. I bought a 12" digital thermometer which I can drop in the oil tank to verify oil temps. Oil in my tank, which will have passed through the cooling system if fully warm, is about 210 to 215 in my system. I bought the thermostat from mcmaster.com, I think. I liked this tool better than an infrared gun device which I've seen others use.

The fact that my system is running at 210 to 215 assures that water in the oil is burned off, which is good.
Doug

[midnight911]

ha ha... we've all gone through this...
The sender on the 95 motor and the gauge you have are not matching. You have to bring the sender from 87 motor or buy a new one to match your gauge.

[mnmasotto]

So I ordered a new oil temp sender unit, part# 323-055-M82. Can I assume this will fix the problem?

[DW SD]

I would hope it will resolve the problem. However, at $10k value for the engine, I'd trust, but verify using the above tests.

Good luck,

Doug

[mnmasotto]

I agree! I am going to measure the temperature of the oil in the tank and take measurements throughout the system. I am also going to remove the thermostat and place it in boiling water to make certain it opens.

One thing I forgot to mention: I have a CHT gauge which seems to stay between 240 - 280F. I am not certain if that muddies the water?

[dad911]

Originally Posted by midnight911

ha ha... we've all gone through this...
The sender on the 95 motor and the gauge you have are not matching. You have to bring the sender from 87 motor or buy a new one to match your gauge.

+1. BTDT, you need the sender from the 87.

[beamonk]

I put the 76 sender on my engine and still get hot as hell temps. Not sure where to go now as I have a stock carerra cooler and a B&B center cooler with a front duct cut-out. I think the long thermometer is a good start.

[mnmasotto]

I replaced the oil temp senor with this part number: 323-055-M82

Unfortunately no change! The gauge temps have not changed. Is this the wrong sensor??

[Bill Verburg]

Originally Posted by mnmasotto

I replaced the oil temp senor with this part number: 323-055-M82

Unfortunately no change! The gauge temps have not changed. Is this the wrong sensor??

The correct sender for the '87 gauge is 911.606.112.00

When I did my first 3.6 t/p both the oil temp and pressure gauges were off, we swapped out the temp sensor for the one that matched the dash guage, but never did the oil pressure which now reads double what the actual pressure is. That's ok as long as you know what it's measuring.

[mnmasotto]

Bill,
Could you please tell me the correct part number for the oil pressure sender unit I need to install. I want correct oil pressure measurements on my 1987 oil pressure gauge.
Thanks Mark

[Bill Verburg]

Originally Posted by mnmasotto

Bill,
Could you please tell me the correct part number for the oil pressure sender unit I need to install. I want correct oil pressure measurements on my 1987 oil pressure gauge.
Thanks Mark

911.606.135.00

but as I said we couldn't get it to fit.

[midnight911]

Originally Posted by Bill Verburg

911.606.135.00

but as I said we couldn't get it to fit.

I have 911.606.135.00 on my 95 3.6 sitting in a 84 chassis with 84 gauge and is working. Had to get this sender since I had higher readings and this fixed it.

[mnmasotto]

Once again, Bill "YOU THE MAN!" I ordered the new part from PP which arrived the next day. Installed the part and once again! Correct temps!
Thanks Bill, PP and all you fellow Pelicans!

[DW SD]

Nice,
What are the temps? Where does it idle?
Congrats, too!

Doug

[mnmasotto]

Conditions:
SoCal low humidity, 88F ambient temp
A/C on Full

Dash oil temp gauge:
When fully warmed up it idles at 190-195F
Heavy spirited driving with multiple redline runs, the oil temp goes up to 220F but cools back down to 200F.

Infrared temp gauge readings:
oil tank - 182F
Finned ER oil lines - 187F
Both front fender oil coolers - 185F

Once again, the correct oil temp sensor sender unit is: 911.606.112.00

[beamonk]

what is the correct sender for temp with a 76?

[Bill Verburg]

Originally Posted by beamonk

what is the correct sender for temp with a 76?

Depends on the dash guage, my '76 has the old style numerical guage and uses 901.641.632.00 but if yours has the newer non numerical gauge use the same as the '87 above.

[beamonk]

Thanks Bill!

[DW SD]

Originally Posted by mnmasotto

Conditions:
SoCal low humidity, 88F ambient temp
A/C on Full

Dash oil temp gauge:
When fully warmed up it idles at 190-195F
Heavy spirited driving with multiple redline runs, the oil temp goes up to 220F but cools back down to 200F.

Infrared temp gauge readings:
oil tank - 182F
Finned ER oil lines - 187F
Both front fender oil coolers - 185F

Once again, the correct oil temp sensor sender unit is: 911.606.112.00

Mark,
I'm just south of you in SDC (Encinitas). Weather is the same, pretty much. I don't have an IR thermometer, but my system stabilizes at a hotter temp. I wonder why? I'd prefer to have my system stabilize at 185F like yours!

Conclusion I came to is the thermostat was opening and closing at a higher temp. Here's what I did: (Note, my temp gauge is calibrated with boiling water before I installed the sender, so I know it reads properly.) 1. Warmed up the car fully. 2. Then let the car idle while I ran cool water from a hose over the oil cooler. This should remove enough heat from the oil in a few minutes to ensure the thermostat opens. When things heat up again the thermostat would open and the water would cool it right back down. In a ten minute cycle, my gauge was pegged at about 205 degrees. I measured oil in the tank iwth a long digital thermometer at about the same time.

Strange that there are different opening / closing points. My themostat is a factory porsche t-stat, about three years old with maybe 3k miles on it. I has been consistent since I have had the conversion running.

Your two coolers have more cooling surface area than my one large nose cooler.


Doug