What exactly is normal "operating temperature"?

[butzi73]

This time a year I always start to worry about how I'm probably not getting my car's temperature up high enough on my daily commute to work. It's a 15 minute drive and on cold days I only get the temp up to about 150, according to my numbered gauge. It's about half way between the first 120 tick and the second 180 tick.

I do drive the car almost every day, and I do try to take the long way home to get the temp up to 180+, but that honestly happens about 1/3 of the time.

I've read the other posts about this. I understand that not getting the oil up to operating temperature will cause internal condensation which can be bad. Is 150 well below operating temperature, or is it probably ok? What is considered operating temperature?

Thanks for your input!

[Paulporsche]

Warmed up was considered by the factory to be 176F (80C) for a 77. That's the temp @ which oil level should be checked. Normal is usually considered to be anywhere from there to 220. Temps of 220 to 240 are getting warmer than normal, except for on long trips or in occasional situations. 240 is hot and Bruce Anderson always said that 250 was "too damn hot!"

Unless it's a very hot, humid day and I'm in stop & go traffic, my engine temps tend to be about 190. This afternoon, in 10-12C temps the engine was @ 180 both in town and on the highway. These engines seem to be affected by the ambient conditions much more than water cooled ones.

[BernieP]

I have the same problem, 15 minute drive each way to work. I try to drive longer on the week ends to get the temp. up especially in the winter months.

[Brando]

I was having the same issue in my carrera... solution: let the car idle for 3-5 mins before driving, on the (short) drive to work stay in a lower gear, keep the rpms near 3500.

[Formerly Steve Wilkinson]

On an '83 SC, the factory says 192 F is oil-checking temperature. Whatever. I consider 180 to be "normal operating temperature."

The basic problem is that a lot of people are doing 15-minute commutes in cars that carry three gallons of oil and were never intended to be used this way. It's like buying a lightplane to make a five-minute flight. No U. S. Porsche dealer would ever have admitted this in in '70s or '80s, but I think Ferry would have. If I want to go to the grocery store, I fire up the Volvo or Boxster. I never start the 911 unless I know I'll achieve operating temp.

[Joe Bob]

180 at all driving speeds and outside ambient temps. Anything more then that, you need more coolers....your thermostat controls the temp, the cooler(s) keep it there....

[Formerly Steve Wilkinson]

That's pretty extreme, to say you need "more coolers" if you exceed 180 degrees. In fact it's nonsense.

[Joe Bob]

Originally Posted by Formerly Steve Wilkinson

That's pretty extreme, to say you need "more coolers" if you exceed 180 degrees. In fact it's nonsense.

I don't think so.....when I converted to a 3.6 in my SC, it ran normally at 180, around town. Any spirited driving at the track or long trips showed elevated temps. Adding another coooler up front along with the Carrera fender well cooler fixed it. Steady 180 temps at all driving conditions and ambient temps.....

I think this proves my point....

[tangerine911S]

After a long enough ride, mine stays steady at about 83C (~181F)

[Bill Verburg]

All of the factory t-stats keep the oil at ~180F+/- a bit. When the temps go beyond that it means that the cooling system is maxed for that state of speed & load. The faster you go the more heat is geerated and the more heat the system can offload so temps will vary up to ~ 220F+/- which is generally considered to be the max you want to run though temps to 240F +/- can and do occur for short periods.

I like to have mine run at ~190F but change oil at 2-3k mile intervals.

The lower the operating temp the slower water is to boil off. The more frequently you need to change oil.

In your shoes where max 150F is seen no oil goes through either cooler, the flow is strictly internal to the engine so you can't even block airflow to the coolers. The only thing you can do is take the long way or pop a 3.6 in there which will warm far more quickly

[m110]

I think the poster's real question is not re: overheating but minimum operating temperature that will not cause problems in the long run. I'm not sure anyone really knows. There was a thread about a Carrera owner some time ago moving to Northern Canada where it was certain he would never reach operating temperature.

[butzi73]

All very interesting. Thanks guys. I guess ultimately the answer is to drive it the long way and get closer to that 180 mark. That's not also that practical, but I will try to be more disciplined about it.

So, I know that idling in the driveway for a few minutes (3-5 was suggested) can also be bad. What is worse, letting it idle for 5 minutes so I can eventually get it up closer to 180 on a more consistent basis, or only getting it up to 150 like I am now?

Is this 150 situation really bad for my car?

Thanks again.

[Joe Bob]

Low temps allow sludge build up....

[Paulporsche]

Bill,

I'm wondering if there is even more to this. Here's an owner who lives near SF and on a "cold" day only sees 150 after 15 min. And even when he takes the long way home, he still usually doesn't get up to 180.

Maybe he is running not enough advance or a too rich mixture.

Today I was @ 176 after 15 minutes in about 10C weather.

butzi73,

You're right. The factory always had the position that the car should be driven right after the enginestarted to run smoothly, which is the best way to bring the temps up. I would think your engine would have to warm up while stationary for quite a long time to get to temp. I have always heard this is bad for bearings. It also wastes gas and pollutes unnecessarilly.

Have you always had this problem? Have you had your mixture and timing checked? What about your spark plugs? Are they correct for your engine?

[Bill Verburg]

Originally Posted by Paulporsche

Bill,

I'm wondering if there is even more to this. Here's an owner who lives near SF and on a "cold" day only sees 150 after 15 min. And even when he takes the long way home, he still usually doesn't get up to 180.

Maybe he is running not enough advance or a too rich mixture.

Today I was @ 176 after 15 minutes in about 10C weather.

butzi73,

You're right. The factory always had the position that the car should be driven right after the enginestarted to run smoothly, which is the best way to bring the temps up. I would think your engine would have to warm up while stationary for quite a long time to get to temp. I have always heard this is bad for bearings. It also wastes gas and pollutes unnecessarilly.

Have you always had this problem? Have you had your mixture and timing checked? What about your spark plugs? Are they correct for your engine?

It's sure that different engines have different warp up times, a 2.4t will take far longer than a 3.6 to reach 180F, it's been a long time but as I recall my 2.4 would not reach 180 no matter what when ambients were in the low 40s, but I didn't drive it much when it got cooler.

[ARCSinAK]

I make many similar short trips on the small island of Kauai, my sc takes a good 10-15 mins to hit 180-190. I work at a fire station that is fifteen minutes from home, sometimes you need the speed hit in the AM....I have also heard that warming up at idle is not recommended , being a carpenter my solution is taking about a 40" 1x1 rip scrap and putting it between accelerator and the drivers seat, thus setting the rpm to between 2-3 grand, for a steady warm up. I usually wash her up let her warm up nicely, then punch it when ever necessary.

Regards-

JS

[butzi73]

Yeah, a cold day for me is only in the 40's. I know that's not very cold to most people, but there is certainly a difference in how easily my oil temp goes up versus a 90-100 degree summer day.

I just had my carbs dialed in perfectly on the dyno (by John Hollerans's Performance in Pinole - He is great!). I know for sure that my mixture is correct. New plugs and wires. It's running better then it ever has. I can't say the temps are any different then they've ever been for me. By the way I have no thermal reactors. I also have an Electromotive crank fire ignition system.

Like Bill just said, on a cold day in the 40's I can drive indefinitely and it won't go past 180, and it takes a while to get there. If I really push it and drive aggressively I can get it past 180. In the summer 200+ is no problem to get to.

Right now in winter I have to extend my 15 minute commute to about 25 minutes to get the temp to 180, with normal driving. Are these normal temps for a carbed 2.7? Should I have any reason to consider the accuracy of my gauge?

Thanks,

[sc_rufctr]

Originally Posted by mikez

180 at all driving speeds and outside ambient temps. Anything more then that, you need more coolers....your thermostat controls the temp, the cooler(s) keep it there....

x2...

The Quoted 180 degrees (82 Celsius) is the ideal. Bear on mind this is the temperature of the oil. Some of the internals are much hotter.

I live in a very hot climate. My 911 warms up quickly and once there stabilises without much variation.
If your cars aren't doing this then that could be an indicator of a problem somewhere.

[scotricker]

My 78 3.0 might be running a little hot, but I'm not sure. It has original gauges with no numbers, but with much research, I have figured that straight left to 9 o' clock position is 200 degrees F, and redline is 300.

I think I'm running close to 240 sometimes, after it's all warmed up.

This is using the original trombone cooler, like it has been for the past thirty years.
But sometimes I think about changing to a radiatior style cooler, and maybe one with a fan, too.

In keeping with the thread topic, I have a short drive to work, but take the long way home sometimes just to be sure it gets warm enough.

But is it getting too hot? How is the best way to verify what the temps actually are?

[Joe Bob]

Originally Posted by scotricker

My 78 3.0 might be running a little hot, but I'm not sure. It has original gauges with no numbers, but with much research, I have figured that straight left to 9 o' clock position is 200 degrees F, and redline is 300.

I think I'm running close to 240 sometimes, after it's all warmed up.

This is using the original trombone cooler, like it has been for the past thirty years.
But sometimes I think about changing to a radiatior style cooler, and maybe one with a fan, too.

In keeping with the thread topic, I have a short drive to work, but take the long way home sometimes just to be sure it gets warm enough.

But is it getting too hot? How is the best way to verify what the temps actually are?

LOOK at your gauge again.....on the far edge are tiny numbers. LIKELY in CENTIGRADE, BUT THEY ARE THERE....