matt33

Started going around in circles on this.. so hoping for some new ideas. Here are the symptoms:

Only occurs when the ambient/outside temperature is < 55F

1. Start car/drive. Engine temp gauge starts climbing, however the oil temp barely moves (perhaps normal?).

2. After 10mins engine temp warning light starts flashing and the engine temp gauge drops to zero/stone cold (oil temp gauge still operating, but heating very slowly).

3. Confirm everything seems ok, disconnect/reconnect battery. Gauges show both engine and oil temps 150ish.

4. 5-10mins later, same issue/warning lights. This will continue until the outside temperature reaches 60F+ at which point the warning light turns off and gauges come back to life. Now the car is warm, the issue will not occur again until the next cold morning.

5. Thermostat replaced, tranny temp sensor replaced, gauges confirmed as accurate vs actual engine/oil/tranny oil temps. Coolant level also fine and the blower fan does turn on/off as you would expect when the car is hot (manual says flashing temp light implies coolant level or blower fan issue).

Found the attached porsche bulletin which suggests replacing the disc valve. Before I get this done.. any other ideas?


Matty

mooty

who's the dealer?
i have the same issue
took few tries to fix. but fremont porsche fixed it

matt33

Joe at Burlingame Porsche for the thermostat (with hindsight, probably wrong diagnosis).
Then Harry Hayashi for the tranny temp sensor. Next step was going to be Marvin at Rennsport (recommended by TCD and Shark).

Do you know what the actual cause was in you car Mooty? Was it this disc valve?

mooty

not sure but tranny temp, disc value, thermostat all replaced

matt33

Ok cool.. since I have 2 of those 3 done already.. might as well replace the disc valve and cross my fingers!

Protocav

Exact same problem and symptoms happened to my car, was definitely the tranny disc valve.

matt33

Fantastic.. thanks for sharing! I really hope that is it - been a massive pita to solve.

Matty

mooty

^ yes i wwnt to dealer many many many times for it.
but the up side is you can drive it. it's not a problem, it's the light that bothers me

matt33

Disc valve replaced.. will test early Saturday and report back whether that is indeed the smoking gun.

Matty

mooty

i takes b/n 50 - 500 miles for it to come back. i know b/c i had a lot of prolems hahaha
if you dont see it after 500 miles, it's pretty much fixed

TRAKCAR

Like Mooty says.
Dealers first change thermostat and waste an extra trip to dealer.

Trans cooler valve. I replaced on all my 997.2RS.
Search trans cooler valve, I posted part# back then.

matt33

What a massive pita... still have the same issue!

Have replaced:
tranny disk/cooler valve (928.574.573.03)
thermostat
tranny temp sensor

What else modulates oil temperature? Is there another valve somewhere? It seems that the engine temp climbs as you would expect, but the oil temperature just does climb until the ambient temperature rises.

I am out of ideas..

Matty

Fisher

Had a corvette where the needle on the dash got hung up. Required a tap on the display bezel after coolant temp indicated temp was up.

matt33

Thanks for the post.. we have confirmed the gauges are correct by measuring actual engine, oil and tranny temps. They are also correctly registering before the warning lights come on.

There must be something else that modulates the oil temperature that is stuck open. Tricky..

Spyerx

Your car is a 997.1? There are some differences in the cooling circuit.

what you indicate is not the tranny valve.
You say water warms faster than oil.
That is Normal

have you checked the engine temp circuit and sensor? Out of the car and in the car measuring at the dme?

Also, any codes pending or thrown on the dme?