991.2 C2S: slow warm up? - Page 1 - 911/Carrera GT - PistonHeads UK

I’m not a Porsche expect but generic advice is that this sounds like the thermostat is stuck open. A dead giveaway is that the heaters will take longer than usual to blow warm.

My 991.1 takes a long time for the oil to warm up to 90 - the water gets to temperature much more quickly. I haven't checked too closely but I'd say maybe 6 or 7 miles at gentle speeds to reach 90 degrees. Worth adding (but I'm sure you know) that in the sports setting the cooling is more efficient - in other words the oil temperature will drop in sports.

Hello all, I think my 991.2 (C2S with Porwerkit) has been warming up a tad too slowly and I think this has been the case since it went to Porsche for maintenance. What makes it weirder is that the oil is warming up not much slower than water, which from memory was not the case. I searched on rennlist but there are several different situations so let me check with you here with a real life situation. Recent drive from the office to home: 4.5 degrees Celsius outside (car having been parked on the street for several hours) and after 3 miles (4.5kms) coolant is at 73C and oil is at 59C. Does that sound right or am I likely to have a problem with my car? Thermostat? If the latter, would it be covered by Porsche approved warranty? Looking forward to your thoughts! Thanks in advance! Edited by Beetle Driver on Sunday 8th December 17:36

Simon_GH said: I’m not a Porsche expect but generic advice is that this sounds like the thermostat is stuck open. A dead giveaway is that the heaters will take longer than usual to blow warm. Thank you Simon! That is a good point that I obviously have sort of forgotten to think of. It does blow cold air for some time... NDA said: My 991.1 takes a long time for the oil to warm up to 90 - the water gets to temperature much more quickly. I haven't checked too closely but I'd say maybe 6 or 7 miles at gentle speeds to reach 90 degrees. Worth adding (but I'm sure you know) that in the sports setting the cooling is more efficient - in other words the oil temperature will drop in sports. Thanks NDA. I guess the oil temperature taking some time is normal. What I did find strange is that the coolant takes that much time. 3 miles and still not fully warm and not that much warmer that oil I find very weird. What would be the normal for your water to get to normal temperature with this sort of cold (4.5C outside)? Edited by Beetle Driver on Sunday 8th December 17:37

If you drive in sport mode warms up slower as third rad is open then. I drive initially without sport or sport plus to warm up quicker

Billy_Whizzzz said: If you drive in sport mode warms up slower as third rad is open then. I drive initially without sport or sport plus to warm up quicker Thanks Billy. That’s clear. I am really referring to normal use, normal mode leaving home and going to the office which is basically <30mph speed all the way (yes, I know, a Porsche is a waste for such use).

Beetle Driver said: Thanks NDA. I guess the oil temperature taking some time is normal. What I did find strange is that the coolant takes that much time. 3 miles and still not fully warm and not that much warmer that oil I find very weird. What would be the normal for your water to get to normal temperature with this sort of cold (4.5C outside)? That is identical to the behaviour of mine. It takes a long while, easily over 3 miles for the coolant/oil to get to temperature. The water is quicker, that's maybe 2 or 3 miles and the oil maybe 6 or 7 (perhaps even a bit longer). It doesn't sound (to me at least) that yours is misbehaving. Engines do take longer than we expect to get fully warm.

I would agree that after 3 miles, 59 C on the oil reading sounds very high considering the fact the car has been parked up for several hours before

NDA said: That is identical to the behaviour of mine. It takes a long while, easily over 3 miles for the coolant/oil to get to temperature. The water is quicker, that's maybe 2 or 3 miles and the oil maybe 6 or 7 (perhaps even a bit longer). It doesn't sound (to me at least) that yours is misbehaving. Engines do take longer than we expect to get fully warm. That’s the thing, I feel the oil is actually normal, what I feel is not normal is the water/coolant which is taking over 3 miles to warm up to the full 90c, to the point where the difference between water and oil temperatures isn’t that big after 3 miles of driving, even if I would be driving pretty much gently (below 2.000rpms).

SV_WDC said: I would agree that after 3 miles, 59 C on the oil reading sounds very high considering the fact the car has been parked up for several hours before That I am not so concerned about, as when it gets up there it doesn’t go beyond normal temp. It’s more the coolant which having its temperature so close to oil makes me think that it’s not just me expecting something unreasonable when the weather is colder to, but instead that there is something wrong with the thermostat…

I’m fairly new to my 991.2 and mine takes at least 4 miles to get to normal temperature.

Had mine over 2 years and the heater is very slow to work. It’s just been in and had a control switch changed , ( drop of engine required) paid for under warranty, still didn’t get warm in the 5 mile drive home ! You’ve just reminded me to call them and get it booked in again , last time they had it for 3 days. 991.2 Carrera 4 GTS Edited by Busa mav on Monday 9th December 15:06

culminator said: I’m fairly new to my 991.2 and mine takes at least 4 miles to get to normal temperature. Thank you! 4 miles would be a good scenario to me. I tested this morning and with the car out of the garage for the weekend (>10C inside, <5 outside) it took it 5.5 miles to get to 90c. If you say 4 miles, would that be in good or bad weather? Busa mav said: Had mine over 2 years and the heater is very slow to work. It’s just been in and had a control switch changed , ( drop of engine required) paid for under warranty, still didn’t get warm in the 5 mile drive home ! You’ve just reminded me to call them and get it booked in again , last time they had it for 3 days. 991.2 Carrera 4 GTS Edited by Busa mav on Monday 9th December 15:06 Thanks! I guess your feedback makes me more at peace. Basically I hear that even 5 miles to warm up is normal (we have the same setup as I have the powerkit) which hence means that my 5.5 miles this morning to get it warm is aligned with a fully functioning car. What still has me puzzled is the small different between coolant and oil temperature gains: only 15c difference after 3 miles of driving…?

Update: wrote an email to my trusted Porsche dealer and they asked for the car for 2 or 3 days, covered under warranty. I suspect they will replace thermostat. God bless the Porsche approved warranty! They are fully booked so will only be possible on January 22nd. Will keep you updated.

It’s also peace of mind kind to have your price and joy checked by a specialist.

Quick update: it went to Porsche and they compared to another similar car and realized the temperature was actually going up as "normal" hence just dropped that item. Using it without any guilt. Its probably because I had been using my car in all weathers, including negative ones, which I didnt on my last one (summer tires only), and this got me slightly paranoid.

It’s always worth checking out something that doesn’t seem right just in case. Glad it’s off the to do list.