Got the new lines swapped. Took her for a little drive and have no leaks. Also seems like the thermostat was working again. Maybe since the oil pressure with non leaking lines was better? Drove for 20 minutes and sat idling at a friends house and it never rose over the first temp line. Side lines were warm/hot feeding the oil cooler in the fender. Seems all good…for now.
Thanks everyone!

Great, thanks for the update. Always good to get closure on a problem.

Thanks for the feedback. So it seems you have Style B gauge as per the doc posted on previous page. If I understand it correctly, your external oil thermostat starts opening at 90°C, that is first temp line.
Mine only opens once the reading on the gauge has reached nearly 9 o'clock. See the pic I posted on previous page. That is only at that reading on the gauge that I can feel both lines are getting hot along the side of the car.
I begin to wonder if my external thermostat is failing. What do you people think? Is this far too late for the external thermostat to open? Sorry to hijack.

@Gilles
I would check at first the temp sensor if this is the right one matching to car and gauge. Then check the electrical connections / contacts, esp. ground.

The oil thermostat from the external oil cooler in the rear right fender is a Behr TO-282 with an opening temperature of 83°C/181°F

More reference numbers of the thermostat:
MAHLE - 1.249.83 / 124983
MAHLE - 70807743 / 70807743
MAHLE - 70809114 / 70809114
MAHLE - TO 2 83 / TO283
PORSCHE - 930 107 155 00 / 93010715500
PORSCHE - 930 107 755 00 / 93010775500

If the temp gauge reading is correct your engine seems to run too hot. IMO mostly a wrong ignirion timing may cause this as it happened to.my SC. but yours is a Carrera with ignition timing being managed by the Motronic. Maybe it runs a bit too lean??? Check the mixture.

Thomas

Thomas

Thanks Thomas. This has been going on for a few years now. Everything is stock on my car. Never changed external thermostat or temp sensor, so they are the same as when they left the Porsche factory. Checking the temp sensor is a good idea. However, right now with cold ambient temps my car runs cold, I mean the needle never go past what I think should be more or less 80°C, that is 3 or 4 mm before first line on temp gauge. This is the maximum I can get even when driving several hours at legal speeds (130 km/h).
This 9 o'clock situation only occurs on hot summer days when ambient temp is around 30°C or over.
But I'm pretty sure it never did that a few years back. The underside oil lines used to get hot at a lower temp reading. This is why I suspect a failing external thermostat. Is it possible that it binds and only opens at a higher than nominal temp?
Thanks. ;)

This is pretty normal and I know this behaviour from my car too earlier. Now - since I replaced the old bigger intermediate pieces the temperatures won't climb that high on hot summer days and the engine runs noticeable cooler anytime.
When your car didn't do it earlier something has changed.
Check the oil lines going to front oil cooler when car is barely driven 2-3 mls...if they are already getting warm too these colder days, the thermostat may have stuck somewhere in between and remains open all the time. Then this may be the culprit...

Thomas