What exactly is normal "operating temperature"?

[mca]

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.

+1

For all of those that never exceed 180 ... bring your car to Charleston, SC in the summer. Drive it hard and then report back.

Unless you have done major mods to your cooling system, you will see temps over 180. Most likely around 200 or 210.

I have a rebuilt 3.0, Elephant Racing finned lines and a carrera cooler (no fan). It is impossible to stay at 180 in my climate during the summer.

Right now with it in the 70s I will see a steady 180. In the winter I have a hard time getting my temps up to 180. But in the summer ... forget it. The high ambient temps + high humidity + afternoon radiant heat from the pavement = beyond 180.

Hell, my water cooled jeep's normal temp is 210.

[ossiblue]

Follow Mike's lead and check the actual numbers to get a true read on your temps. However, most would agree that the trombone is inadequate for a 3.0 and a radiator style cooler, preferably with a fan, should be installed. Given that you are in a hot climate, I'd say switch out to a more efficient cooler as soon as possible.

[wdfifteen]

I have a 1988 Carrera without numbers on the temp gauge. In normal driving the needle doesn't make it into the "normal" range. Even after 20 minutes on the track the indicator barely gets up there and I have never seen it in the center of the red range. I was told by the PO and by a Porsche mechanic that this was the normal way these gauges display, but I'm beginning to wonder. It this true?

[RexNoctu]

My '88 runs just above the second tick mark no matter how long it runs for. Once over the summer in heavy stop and go it got almost to the third mark. I think if I ever saw it climb above there I would pull over and let it cool for awhile. My commute is 1+ hour each way with good traffic, I think that day it took me almost 3 hours one way.

[wdfifteen]

I found my answer on this thread
Temperature on 86 Carerra
Looks like my car is normal.

[911pcars]

Originally Posted by mikez

Low temps allow sludge build up....

Exactly. Normal op. temp. is when all the engine component temperatures are normalized and dimensionally accurate. That's around 190-220ºF. The lower in that range, the better.

However, the oil must be warm enough to burn off condensation from the combustion process.

If the temp. gauge reads 180ºF, you're probably okay.

It may be unavoidable to bring the vehicle up to op. temp. at every cold start. In that case, change oil more frequently to remove harmful deposits and acids from the lube oil.

Sherwood

[mickey356]

I'm a little confused by all this. These cars are made in Germany. It gets cold in Germany. Whats the difference in the way the cold/operating temps/time it takes to get to operating temp, etc..... affect these cars? Why do they have to get to operating temp everytime you drive? Is it just the condensation issue? If that is as harmful to the engine as it being implied in this thread it seems like a serious design flaw on Porsches part, no? Did they continue to make these cars with the intent to drive them until they reach proper operating temp in order to boil off water in the oil for the entire time they made them?
I have a 5 mile drive to work everyday. I'm not sure if I'm not getting to to operating temp (it gets to just shy of the second white mark) but I think I do. But it seems awfully silly to make a car that shouldn't be warmed up at idle yet needs to be driven hard to reach operating temp everytime you drive. It's only gonna get colder over the next few months and I may have made a grave error in buying a 911 as my daily driver.

[ossiblue]

Originally Posted by mickey356

I'm a little confused by all this. These cars are made in Germany. It gets cold in Germany. Whats the difference in the way the cold/operating temps/time it takes to get to operating temp, etc..... affect these cars? Why do they have to get to operating temp everytime you drive? Is it just the condensation issue? If that is as harmful to the engine as it being implied in this thread it seems like a serious design flaw on Porsches part, no? Did they continue to make these cars with the intent to drive them until they reach proper operating temp in order to boil off water in the oil for the entire time they made them?
I have a 5 mile drive to work everyday. I'm not sure if I'm not getting to to operating temp (it gets to just shy of the second white mark) but I think I do. But it seems awfully silly to make a car that shouldn't be warmed up at idle yet needs to be driven hard to reach operating temp everytime you drive. It's only gonna get colder over the next few months and I may have made a grave error in buying a 911 as my daily driver.

Any engine, Porsche or not, will "suffer" by continual use in very short drives--ie. five minute jaunts to the market--unless maintenence schedules are changed. Nearly all engines are designed for long duration running under a wide variety of conditions and most driver manuals offer alternatives if the car is operated for extended periods outside "normal" conditions. Short, below warm-up running is definitely outside the normal condition, but is not harmful on occasion. An engine which is run for only a five mile daily trip is one, IMO, that should be given special service--more frequent oil changes--to keep it healthy and happy.

[Shadetree930]

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....

210 boils the cheese off the oil.

[wdfifteen]

Originally Posted by mickey356

I'm a little confused by all this. These cars are made in Germany. It gets cold in Germany. Whats the difference in the way the cold/operating temps/time it takes to get to operating temp, etc..... affect these cars? Why do they have to get to operating temp everytime you drive? Is it just the condensation issue? If that is as harmful to the engine as it being implied in this thread it seems like a serious design flaw on Porsches part, no? Did they continue to make these cars with the intent to drive them until they reach proper operating temp in order to boil off water in the oil for the entire time they made them?
I have a 5 mile drive to work everyday. I'm not sure if I'm not getting to to operating temp (it gets to just shy of the second white mark) but I think I do. But it seems awfully silly to make a car that shouldn't be warmed up at idle yet needs to be driven hard to reach operating temp everytime you drive. It's only gonna get colder over the next few months and I may have made a grave error in buying a 911 as my daily driver.

"I may have made a grave error in buying a 911 as my daily driver." You may have. Repeated cold running has the same effect on whatever car you drive for 5 miles at a time. It's not that a 911 is any more susceptible, it's that most people care more about preserving their Porsches than their Accords or Camrys. In the past 40 years I've been through half a dozen daily drivers, but I still own the same Porsches. Daily drivers are vehicles I sacrifice to my interest in Porsches.

[Formerly Steve Wilkinson]

Basic difference: Porsches are not "cars."

[mickey356]

Maintenance book says to change oil and replace filter every 15K.
Also under Severe Condition Maintenance
More frequent maintenance than specified in the Maintenance Schedule is required if you drive under severe operating conditions. They include:
More frequent engine oil and filter changes for extended idling or low speed operation.
More frequent engine oil, oil filter and air filter replacementsunder severe dust condition, driving on unpaved roads or off road.
Frequent cleaning of radiator grille and core to prevent debris from restricting the cooling system (928, 944)
Cleaning and bleeding of fuel system may become necessary if contaminated by water, foreign matter, dirt or residue.
Owners Manuel says Oil Temperature has an influence on the service life of the engine. After starting the engine, drive at moderate speeds until the oil temperature gauge needle has reached the end of the white field. When the needle has blimbed to the first white line of the scale, the engine has reached operating temperature (194 F/90 C). etc.....

I've had my car for 4 months (4k miles) and have changed the oil and fitler twice. Being that it's recommended to change every 15K is it save to say I'll be OK changing every 3-5K?
It's not that I only drive it 10 miles a day but more often than I'd like I am running around town. I get it out on the highway or through the back roads about once a week. I'd really hate to not be able to enjoy my car. As much as I really (REALLY) like driving on the highway and back roads I still like driving my car all the time regardless.

As an afterthought - I still can't wrap my head around the "getting the car to operating temp" thing. How can it be an issue if you don't always get your car to 194F when driving? Regardless of how long you drive the car if the car starts cold (needle at the bottom of oil temp gauge) you still have to get it up to operating temp. So doesn't the engine have to run "cold" until it gets to temp? How is it starting a cold engine and getting to temp is anymore beneficial? Whether you reach operating temp or not the engine still has to run cold for awhile, no? Why is always getting it from cold to 194F important? What if you drive in a place where the temps are bitter cold in the winter and regardless of how long you drive the car can't get to 194F? Are you not supposed to drive? I'm confused as to why Porsche (Germany, where it gets cold) would make a car that can only be driven in fair weather climates. I know I may sound dumb asking these questions but it doesn't seem right to me. I'm sure I'm missing something here. The wear and tear physics of it don't seem to make sense if you're always starting cold.

[spinner37]

i have the gauge with no numbers on it on my 77. when it is warm outside, it gets about 1/16 to 1/8th above the white. so i just went and looked for the hidden numbers on the left of the gauge. they are there, very hard to read though. it seems the top of the white is 99 degrees C ??? my car has never gone above 1/16 or 1/8th over the white, even on a 90 degree F day. now it is 40 degrees F. if i drive it hard for 15 miles, it is just getting into the white. i change the oil every 2000 miles..... subscribed PS, does anybody know what those tiny nubers to the left of the gauge are? looks to be 4 of them at different spots on the gauge. really hard to read.....

[chris.817]

Apparently those numbers are the Deg C readings. My guages were covered by the PO in white so whatever marking mine had are gone...

[Dueller]

Originally Posted by spinner37

i have the gauge with no numbers on it on my 77. when it is warm outside, it gets about 1/16 to 1/8th above the white. so i just went and looked for the hidden numbers on the left of the gauge. they are there, very hard to read though. it seems the top of the white is 99 degrees C ??? my car has never gone above 1/16 or 1/8th over the white, even on a 90 degree F day. now it is 40 degrees F. if i drive it hard for 15 miles, it is just getting into the white. i change the oil every 2000 miles..... subscribed PS, does anybody know what those tiny nubers to the left of the gauge are? looks to be 4 of them at different spots on the gauge. really hard to read.....

Temp in Celsius.

[Dueller]

Here's a pic of the numbers exposed with Fahrenheit conversion:

[spinner37]

hum, my gauge is a little different, but it seems mine runs around 190 if the second number is 90 Centigrade.....that is where my gauge goes to, the second little number.... it has trouble getting there when it is cold outside!

[Rrrockhound]

Originally Posted by mickey356

As an afterthought - I still can't wrap my head around the "getting the car to operating temp" thing. How can it be an issue if you don't always get your car to 194F when driving? Regardless of how long you drive the car if the car starts cold (needle at the bottom of oil temp gauge) you still have to get it up to operating temp. So doesn't the engine have to run "cold" until it gets to temp?

It's an issue because running the engine creates combustion byproducts (some corrosive) that won't be fully burned off if you don't reach full temp. Start a typical engine and notice how much water comes out of the tailpipe until it's hot. That's not distilled water.

Another example: when you grill outside and shut down your grill after cooking, it's full of grease and gunk, right? But if you close it up and let it keep burning, eventually the crap burns off into soot. Not only is it easier to clean, but the grill will last longer.

[wdfifteen]

Originally Posted by mickey356

As an afterthought - I still can't wrap my head around the "getting the car to operating temp" thing. How can it be an issue if you don't always get your car to 194F when driving? Regardless of how long you drive the car if the car starts cold (needle at the bottom of oil temp gauge) you still have to get it up to operating temp. So doesn't the engine have to run "cold" until it gets to temp? How is it starting a cold engine and getting to temp is anymore beneficial? Whether you reach operating temp or not the engine still has to run cold for awhile, no? Why is always getting it from cold to 194F important? What if you drive in a place where the temps are bitter cold in the winter and regardless of how long you drive the car can't get to 194F? Are you not supposed to drive? I'm confused as to why Porsche (Germany, where it gets cold) would make a car that can only be driven in fair weather climates. I know I may sound dumb asking these questions but it doesn't seem right to me. I'm sure I'm missing something here. The wear and tear physics of it don't seem to make sense if you're always starting cold.

Getting the engine oil hot "boils off" contaminants such as water vapor that condenses in the crankcase and fuel that gets past the rings. If you seldom get the oil hot enough to cause contaminants to evaporate, they build up to levels that are significant enough to damage the engine. A few short runs are fine, but the oil needs to be thoroughly warmed up occasionally. I'd say once a week at least. It's the same for every engine. Porsches are not especially susceptible to this. Porsche owners just care more.

[Formerly Steve Wilkinson]

"Porsches are not especially susceptible to this."

Actually, they are, because their cooling medium is for the most part oil, and 911s carry three gallons of it. Our Volvo V50 brings its few quarts of coolant up to operating temperature in about five minutes of gentle driving even in winter temps, and our Boxster takes only a minute or two longer.