Cold Weather & Engine Temperature

[toals]

On recent run down from Coventry on the M40 to London, the temperature gauge never made it past the 80C mark. The ambient temp was around 3C but I would have expected the engine temp to have been over 80C. Interestingly, once we hit heavy London traffic the needle was back to normal ie about 85-90C. Is this low reading normal or do I have a problem ? Also how long does your car take to warm up from cold; mine is taking around 6 miles which sems a bit slow !
Any input gratefully received.

 

[adrian996]

Hi Seamus. I'm not driving my 996 at the moment as she's in bed for as long as I can bear it. I have a second car for work - an old 1989 Mercedes 190E that's done 150,000 miles and runs like a watch. I've noticed exactly the same thing on my Merc and my wifes Citroen; they're both taking longer to warm up and don't tend to quite get up to the normal running temp. I've wedged half an old number plate in front of my Merc radiator and it's made quite a difference. She warms up more quickly and runs nearer normal temp or slightly higher - which is fab!
You've only got to look at the front of a 996 to see how exposed to the air the radiators are - I can almost see yours on your picture! If it was 3 deg C and your you were pootling along at say 70 mph then you can imagine the wind-chill factor created there. It must be bloody knobling at the front of your car! The only other possible explanation is that your thermostat is open all the time - ie. knackered, but I think that this it very unlikely as you seemed to reach temp when in traffic. Adrian.

 

[Richard_Hamilton]

Mine is taking longer to warm up in this cold weather.

I the "summer" I checked the warm up time for someone else who thought theirs took a long time to warm up. This is what I got, one morning when the OBC read 14C, It was moving continuously at 30-40mph, and the engine was cold at the start of the run:
1.3 miles - 40 C2.3 miles - 60 C3.7 Miles - 80 C4.8 miles - Normal operating temperature (between the 8 and 0 of 80) I would guess that mine is now taking a good mile longer to warm up, but it does reach the normal temp on the 7 mile run across town each morning. I haven't been on a motorway run in the last few days, but I think Adrian is right, and I don't think you have anything to worry about.

 

[toals]

Adrian, Thanks for your input; I have to say I was pootling along a tad faster than that but at my age you have to get your thrills anywhere you can.[]
I am not sure that the normal temp in traffic means the stat is working OK; it looks like it could be sticking open so that with max cooling from the rads at mach 2 the engine is running cool but when the airflow is much reduced it holds a reasonable temp.
Richard, Thanks for the warm up data, I think my times are well outside what you are getting. Indeed when I join the motorway and give her a bit of wellie up to mach 2 the engine temp can drop by 15-20C due to the increase in cooling air. I always thought the stat would sense the change and reduce the flow to the rads in a few seconds. I will see what the OPC has to say about it next week.
Thanks.

 

[NXI20]

Just to concur with Richard, normal operating temp is a tad over 80 for me, summer or winter irrespective of speed - even stuck in London traffic in the summer!

 

[John Ware]

The oil won't heat up quite as quickly as the water. My A6 has both oil and water temp gauges and the oil lags the water by about five minutes to get to normal operating temp.