treetrimmer

I did a search on these terms and mostly came up w/ over-heating threads, I have possibly the opposite problem, (at least in cool weather). I haven't had my car very long and it seems to take an inordinate amount of time to reach operating temp in even mildly cool weather. This morning on my drive to work, it never reached normal (180) temp in ~12 minutes of mixed city and highway driving. It was about 50 deg. F. It only got to the first line above 100, which is the bottom of my gauge.

I called the dealer to ask a service advisor about it and he could not say with certainty that this was abnormal, but he did say that he "could not remember the last time they had to replace a thermostat on a 996 due to failure." It's a fairly busy dealer. Said they would have to run tests on it to know, etc...

So I'm tapping the brain/experience trust here: How long does it take for your 3.4 996 to fully warm-up from cold? If you could include approx. ambient temps, that would be helpful. Thanks a lot in advance as always!

1999Porsche911

Your themostat is 83C which means that it will not open to allow coolant to radiators until the coolant in the engine reaches that temperature. You possibly have a thermostat stuck open or a faulty temperature sending unit or gauge. In 12 minutes of driving you should be well above 100F. Without a thermostat, my engine will reach 150+ in <10 minutes even in the coldest of temperatures, so I suspect it is a gauge or sending unit problem and you are not seeing the actual coolant temperature.

Tippy

The fact it doesnt raise the gauge past 100 degree mark makes me think it is simply the temp sensor.

Riad

Or warped rotors.

michael.s.under

Riads right, sounds like the thermostat was quenched with cool water at very, very high heat!

treetrimmer

What I wrote was that it only gets to the first line above 100, and that 100 is of course the bottom of the gauge. Not that it only gets to 100. What is the line between 100 and 180? 150 deg.? That's about where it goes. I do not suspect the gauge or sender, I think that it's reading correctly. In hot weather and traffic it reads in the middle of the "180" or above in stop-and-go, just like other people's cars that I've read about here.

So once again, the question is how long it takes for your 3.4 996 to reach operating temp on a cool (50 deg.) day? I'm calling OT ~180F. Thanks!

redridge

I heard that if you use %100 anti freeze (radiator fluid) it will make your car run much cooler... is it this case?

dresler

No.

dresler

About 10-15 min. Do you ever get to 180 on a cold day?

1999Porsche911

Use the climate control screen to look at your coolant temperture. Normal operating temperture if 90C+ no matter how cold it is. If the screen shows normal temp, then it is your gauge or the wire feed to it..

treetrimmer

Thanks, I'll do that. What is the button sequence again for doing that?

1999Porsche911

Press and hold in the recirculate and the top (arrow up) buttons on the right side of the panel for a few seconds. The left screen will change. Using the + key below that screen, adance so the display reads 6c. Then press the center vent button once. The display will show you your coolant temp.

To go back to normal, simply press AUTO.

Porsche_Smile

try the sender unit....