What is the normal water temperature?

[smak]

Hi,

After days of driving, I have found that the water temperature is about 10-20 F higher in city driving than highway. Is that normal?

The picture below is the city driving reading. Highway reading is just above 180F.

[1999Porsche911]

Targeted coolant temp is 194F and on cool days at highway speeds, you can maintain this temperature close enough. Turning the AC on will increase temperatures, partially offset by fan operation. Around town, coolant temps can reach as high as 220F+. Sunny days add to temps. Based on your gauge, your temp is around 215F. You will see 180F only twice during a drive cycle. Once while you pass by it as the engine warms up and once when you pass by it after engine shut down.

[Loren]

Hi,

After days of driving, I have found that the water temperature is about 10-20 F higher in city driving than highway. Is that normal?

The picture below is the city driving reading. Highway reading is just above 180F.

Looks normal to me.

[phillipj]

That's about where my temps have been in both 996's. I have never had either of my cars ever go below the "0" of the 180 in any conditions.

Edited August 10, 2009 by phillipj

[smak]

thanks all.

Loren, I read your 3rd or center radiator DIY upgrade. Will it lower the temperature in city driving condition of just hard track driving only?

thx,

That's about where my temps have been in both 996's. I have never had either of my cars ever go below the "0" of the 180 in any conditions.

[Loren]

thanks all.

Loren, I read your 3rd or center radiator DIY upgrade. Will it lower the temperature in city driving condition of just hard track driving only?

thx,

That's about where my temps have been in both 996's. I have never had either of my cars ever go below the "0" of the 180 in any conditions.

It won't do much in city driving as the added capacity is only a few liters. But once you are moving I think it helps quite a bit.

Of course, be sure to check the radiators on your car now (and AC condensers) for debris that rob the cooling efficiency.

[smak]

thanks,

I am planning to do a full radiator flush anyway.

thanks all.

Loren, I read your 3rd or center radiator DIY upgrade. Will it lower the temperature in city driving condition of just hard track driving only?

thx,

That's about where my temps have been in both 996's. I have never had either of my cars ever go below the "0" of the 180 in any conditions.

It won't do much in city driving as the added capacity is only a few liters. But once you are moving I think it helps quite a bit.

Of course, be sure to check the radiators on your car now (and AC condensers) for debris that rob the cooling efficiency.

[Falcon900EX]

My 2003 911 never goes above the zero no matter what I'm doing, city or highway. That's how I know when she's up to temp before I start to tach it up. E ;)

[Dennis C]

Mine runs just over the line for 180. This doesn't seem to change in the city vs. the highway, or even if it is really hot outside and I am running the A/C.

[perryinva]

Not to be argumentative, but I'd say his indicated temperature in the above pic is much closer to 202F, than 215F, which is also a considerably more normal temperature. Most every gauge that is non-linear, like the one shown, puts non labeled hashes at 50% of the difference between labels. Obviously, these are not any type of precision indication, and on my '02, I can't do the climate control hack, but I'd put the first unmarked hash at 140F and the second one at 215F. I know when I hooked up my Autoenginuity laptop to the OBD port and monitored temps, when mine was just at the right edge of the zero in 180, like his, or a bit more, I was at 203F. To get there I had to have AC off, and drive in 3rd on the interstate at about 70mph. Otherwise, during normal driving and commuting, I never see that gauge move off directly between the eight and zero, or 195F.

[Robert Wright]

My 99' C2 runs at nearly he same temps as you describe, maybe just a tick lower. Normal summer highway driving indication is right between the 8 and the 0 and varies slightly based on outside air temps. In town it bumps 10-15 degrees and varies slightly running around the left edge to middle of the 0. Car has spotless radiators now, flushed and tight coolant system.

[Benjamin Choi]

i notice that when i have the AC on the car runs cooler cuz the fans are on

[JamesD]

There's two things I find I'm always looking at and that's the Tempature & Oil,

(I'm obbsessed with this since a new engine install a while back)

This tempature reading in the picture looks normal for city driving.

But I'd say once your speed reached say about 60/70 mph it should settle down to around the 180 point? (increse a bit if AC is on)

I find when doing slow movement driving of any sort (traffic) the 911's tempature is never happy.

On my 996's last major service I added to the coolant tank RedLine Water Wetter you can mix this with the porsche coolant,

it help's to eliminate hot spot's forming in the engine maybe it's just my imagination but I find it really help's to keep the motor running cool.

When I'm doing between say 60/100 mph the tempature is perfectly on 180 even a little behind the number 8 and the oil is right up at mark 5

then say at 40/50 mph the oil is at 4 mark and the tempature is still at 180. (of course this all increse's to about 190 if the AC is on)

When in slow stop/start traffic the tempature is well over 180 and oil is inbetween 1 & 2 or just above 1. (not nice to be in)

I guess the more speed the more cool fresh air is been sucked in. This and a nice clean coolant tank, clean radiators & fresh coolant + water wetter

all make the differance to keeping the tempature down.

Edited August 17, 2009 by JamesD

[perryinva]

There's two things I find I'm always looking at and that's the Tempature & Oil,

(I'm obbsessed with this since a new engine install a while back)

This tempature reading in the picture looks normal for city driving.

But I'd say once your speed reached say about 60/70 mph it should settle down to around the 180 point? (increse a bit if AC is on)

I find when doing slow movement driving of any sort (traffic) the 911's tempature is never happy.

On my 996's last major service I added to the coolant tank RedLine Water Wetter you can mix this with the porsche coolant,

it help's to eliminate hot spot's forming in the engine maybe it's just my imagination but I find it really help's to keep the motor running cool.

When I'm doing between say 60/100 mph the tempature is perfectly on 180 even a little behind the number 8 and the oil is right up at mark 5

then say at 40/50 mph the oil is at 4 mark and the tempature is still at 180. (of course this all increse's to about 190 if the AC is on)

When in slow stop/start traffic the tempature is well over 180 and oil is inbetween 1 & 2 or just above 1. (not nice to be in)

I guess the more speed the more cool fresh air is been sucked in. This and a nice clean coolant tank, clean radiators & fresh coolant + water wetter

all make the differance to keeping the tempature down.

I've never been able to find anything in writing that states that Water Wetter is safe to use with Porsche extended coolant. Water Wetter ststaes it's safe for all coolants, butit came out way before the Porsche extended stuff did, so I'm not sure it has ever been tested. ASny info you have on it would be great. I used it on all my other cars, and it was a noticeable improvemnt in temperature, but both my "03 Passat and the 996 have similar coolant that I'm hesitant to "experiment" with.

[smak]

Thank you all.

It seems that most 996s runs around the "8 and 0" range during city driving. Anyone runs over the 215F mark? Would that be considering overheat? What will be the acceptable temp on track?

smak

My 99' C2 runs at nearly he same temps as you describe, maybe just a tick lower. Normal summer highway driving indication is right between the 8 and the 0 and varies slightly based on outside air temps. In town it bumps 10-15 degrees and varies slightly running around the left edge to middle of the 0. Car has spotless radiators now, flushed and tight coolant system.

[JamesD]

There's two things I find I'm always looking at and that's the Tempature & Oil,

(I'm obbsessed with this since a new engine install a while back)

This tempature reading in the picture looks normal for city driving.

But I'd say once your speed reached say about 60/70 mph it should settle down to around the 180 point? (increse a bit if AC is on)

I find when doing slow movement driving of any sort (traffic) the 911's tempature is never happy.

On my 996's last major service I added to the coolant tank RedLine Water Wetter you can mix this with the porsche coolant,

it help's to eliminate hot spot's forming in the engine maybe it's just my imagination but I find it really help's to keep the motor running cool.

When I'm doing between say 60/100 mph the tempature is perfectly on 180 even a little behind the number 8 and the oil is right up at mark 5

then say at 40/50 mph the oil is at 4 mark and the tempature is still at 180. (of course this all increse's to about 190 if the AC is on)

When in slow stop/start traffic the tempature is well over 180 and oil is inbetween 1 & 2 or just above 1. (not nice to be in)

I guess the more speed the more cool fresh air is been sucked in. This and a nice clean coolant tank, clean radiators & fresh coolant + water wetter

all make the differance to keeping the tempature down.

I've never been able to find anything in writing that states that Water Wetter is safe to use with Porsche extended coolant. Water Wetter ststaes it's safe for all coolants, butit came out way before the Porsche extended stuff did, so I'm not sure it has ever been tested. ASny info you have on it would be great. I used it on all my other cars, and it was a noticeable improvemnt in temperature, but both my "03 Passat and the 996 have similar coolant that I'm hesitant to "experiment" with.

Hey Perry,

I've never found anything in writing too, but I found the Water Wetter at www.porscheshop.co.uk a porsche specialist in the uk, so that was good enough for

me :) and I find it has made the differance, I've drove for about 4000k in the last 2 weeks and its has deffently proved itself.

[woodenewe]

I too have a new engine in my 1999 996 C4 and have experienced what appears to be high temps even after normal freeway driving in cool (65F) weather. The engine temp rises above the “180” mark with A/C on in warm (80’s) weather and the warning light starts flashing. The gage can almost gets to the next mark (what ever temp that is) in hot (90’s) weather. I also notice that the engine compartment fan consistently runs for a few minutes after shut down. The old engine never did that. In an earlier thread I was advised to clear the radiator and then if needed, replace the thermostat. I’ve cleared a few bits of debris (with the bumper still on) and viewed the back area with a bore scope; mostly clear, just a couple of leaves still stuck in the far back. I plan to take the radiator off when I have more time.

I admit to being hypersensitive as I've already had one major failure with the new engine; oil in the coolant. The oil cooler had to be replaced and the cooling system repeatedly flushed to remove the oil. It is thought the thermostat may be faulty due to residual oil contamination thus causing the flashing light. The car was at the dealer for almost two weeks while they repeatedly flushed out the oil. Also the coolant tank had to be replaced as they were not sure they could get all the oil out of it.

I’ve got a trip planned for the weekend after next and will plug in my laptop and track temps et al with Durametric software, with my wife recoding the data. That may help understand what all is going on.

\Bob

[JamesD]

I too have a new engine in my 1999 996 C4 and have experienced what appears to be high temps even after normal freeway driving in cool (65F) weather. The engine temp rises above the “180” mark with A/C on in warm (80’s) weather and the warning light starts flashing. The gage can almost gets to the next mark (what ever temp that is) in hot (90’s) weather. I also notice that the engine compartment fan consistently runs for a few minutes after shut down. The old engine never did that. In an earlier thread I was advised to clear the radiator and then if needed, replace the thermostat. I’ve cleared a few bits of debris (with the bumper still on) and viewed the back area with a bore scope; mostly clear, just a couple of leaves still stuck in the far back. I plan to take the radiator off when I have more time.

I admit to being hypersensitive as I've already had one major failure with the new engine; oil in the coolant. The oil cooler had to be replaced and the cooling system repeatedly flushed to remove the oil. It is thought the thermostat may be faulty due to residual oil contamination thus causing the flashing light. The car was at the dealer for almost two weeks while they repeatedly flushed out the oil. Also the coolant tank had to be replaced as they were not sure they could get all the oil out of it.

I’ve got a trip planned for the weekend after next and will plug in my laptop and track temps et al with Durametric software, with my wife recoding the data. That may help understand what all is going on.

\Bob

Sound familiar, I too had similiar situation.

I was going to suggest that you change your coolant tank + hose's but you've already done that? So I would maybe give the radiators a major clean out (bumper off job) aslo try replacing the thermostat. I have been using RedLine Water Wetter you can also mix this with your porsche coolant to help stop any hot spots forming in the engine. I find it wont harm the motor it's just some extra protection.

Best of luck with this, keep us informed.

Edited August 21, 2009 by JamesD

[goldenwarrior1]

I too have a new engine in my 1999 996 C4 and have experienced what appears to be high temps even after normal freeway driving in cool (65F) weather. The engine temp rises above the “180” mark with A/C on in warm (80’s) weather and the warning light starts flashing. The gage can almost gets to the next mark (what ever temp that is) in hot (90’s) weather. I also notice that the engine compartment fan consistently runs for a few minutes after shut down. The old engine never did that. In an earlier thread I was advised to clear the radiator and then if needed, replace the thermostat. I’ve cleared a few bits of debris (with the bumper still on) and viewed the back area with a bore scope; mostly clear, just a couple of leaves still stuck in the far back. I plan to take the radiator off when I have more time.

I admit to being hypersensitive as I've already had one major failure with the new engine; oil in the coolant. The oil cooler had to be replaced and the cooling system repeatedly flushed to remove the oil. It is thought the thermostat may be faulty due to residual oil contamination thus causing the flashing light. The car was at the dealer for almost two weeks while they repeatedly flushed out the oil. Also the coolant tank had to be replaced as they were not sure they could get all the oil out of it.

I’ve got a trip planned for the weekend after next and will plug in my laptop and track temps et al with Durametric software, with my wife recoding the data. That may help understand what all is going on.

\Bob

Sound familiar, I too had similiar situation.

I was going to suggest that you change your coolant tank + hose's but you've already done that? So I would maybe give the radiators a major clean out (bumper off job) aslo try replacing the thermostat. I have been using RedLine Water Wetter you can also mix this with your porsche coolant to help stop any hot spots forming in the engine. I find it wont harm the motor it's just some extra protection.

Best of luck with this, keep us informed.

This has been covered here before but thought I would share the pics of my recent radiator cleaning. I sprayed the coils down with an aluminum clearner and was amazed at the grime flushed out... Made a definite difference in my 02 C4S.

[woodenewe]

Porsche 1999 C4 996 over heating concern; initially reported on August 21, 2009

After having the engine replaced, I noticed the engine compartment cooling fan would come on after shutting the motor down, even when the ambient temperatures were in the 50's F. In hot weather with temps over 90 F or so, the over temp light would flash. At the time we were in Nevada in July and just had to wait until sundown to drive any distance. We took it into a dealer in Reno who said that other than some grasshoppers, the radiators looked clean. And of course, we ran with the A/C turned off. The car, a 1999 996 C4 sat in the barn over winter and saw little road time. Now as spring has returned, so has the flashing overtemp light, again with outside temps only in the 60's.

So following the advice given last year; I pulled the bumper cover and cleaned out the radiators. Not surprisingly both were covered with debris over 30 percent of the frontal area. The debris was leaves, bugs, and a stiff coating of dust with the majority of it on the engine radiator, not on the A/C heat exchanger. The borescope could not see the area where all the junk was. Interesting how the dirt got packed into the space between the two. Cleaning was done with a vacuum and soft bristle brush; perhaps I should have pressure washed the radiators, but was not able to do so inside the garage. Next time I'll do the tear down outside and do a better job.

Problem solved? The overtemp light has not flashed after driving in stop and go traffic. However, the fan still comes on after shutdown. The dashboard gage quickly climbs to "180" with the needle right between 8 and 0 (and it is still no warmer outside that the mid 60F's). So far it has not gone above the indicated "180" under varying driving conditions. The fan typically runs 2 to 3 minutes after shutting the engine down, and then turns off.

My concern is with the factory replacement engine, now with less than 6 months of warranty remaining; is there something still wrong? Again the old motor hardly ever ran the fan after turning it off. I initially attributed the situation to a new motor that might be a bit "tight". However with more than 5000 miles on it, I doubt that is the reason for the apparent excess engine heat.

Earlier in the warranty period I experienced the dreaded oil in the coolant problem. After more than a week in the shop, the dealer found the "new" oil cooler was leaking oil into the coolant. After replacing the cooler and many fill and flush cycles later using the "special" factory specified block coolant cleaner (all under warranty), that problem was said to be resolved. I fear I may still have a problem and after sinking an amazing amount of money into the car, I can't believe that I have to go through the warranty claim process again.

But I will, with vigor. Is my experience as described a cause for concern? If so, what might I do to verify there is a problem before taking it back into a dealer? I plan to start taking temp data with Durametric software and would like to know which parameters are of significance to my situation? Hopefully recording the pertinent data should either help to clear my concerns, or verify there is a problem. There were no fault codes in the memory at last check.

Any and all suggestions are most appreciated.

[whall]

An operating temperature with the needle between the 8 and 0 seems to be typical of most cars.

The fact that your engine compartment fan is coming on could be because the compartment temperature sensor could be loose and touching something hot. Perhaps the "technician" who replaced your engine missed that part of the installation.

I'm not sure of the exact location of the temperature sensor, but there is a lot of expert help here who does.

Bill

Edited May 16, 2010 by whall

[nghiaho58]

An operating temperature with the needle between the 8 and 0 seems to be typical of most cars.

The fact that your engine compartment fan is coming on could be because the compartment temperature sensor could be loose and touching something hot. Perhaps the "technician" who replaced your engine missed that part of the installation.

I'm not sure of the exact location of the temperature sensor, but there is a lot of expert help here who does.

Bill

You can read the coolant temperature in the diagnostic mode that shows on the display at the console. I use it to monitor the engine temp while driving.

Here is the info I got from Rennlist forum.

-----

To access diagnostics:

Hold down the Recirculating & Air up buttons for 5 seconds. The + - buttons go up and down through the list of "c" codes. The center vent button switches the left display between the "c" code and its actual value. Press the Auto button to exit.

I have yet to verify all these, this info was copied from wonderful people on PPBB!

Here is a list of what can be seen:

0c - ERL

1c - Oil Temp?

2c - Inside temp. Sensor mounted in the aspirator assembly at the side of the dash.

3c - Outside temp. Sensor located inside the air inlet of the A/C unit.

4c - Outside temp. Sensor located in front grill of the radiator. The data is fed to the Climatronic from the instrument cluster. When not moving, the instrument cluster OBC temp display retains it's last setting until moving. This is to prevent heat emanating from the radiator affecting the temperature sensor. The A/C unit uses the lower of the two outside air temp values in determining fresh-air temp.

5c - Outside temp. (matches OBC outside temp display)

6c - Coolant temp.

7c - Footwell discharge temp.

8c - Sun sensor (dash top)

9c - Sun sensor.

10c - Passenger compartment fan speed.

11c - Passenger compartment fan voltage.

12c - Temperature mix Flap command 1=COLD, 100=HOT

13c - Temperature mix Flap position

14c - Central Flap command

15c - Central Flap position

16c - Footwell/Defrost Flap command

17c - Footwell/Defrost Flap position

18c - Recirculation Valve command 1=OFF, 100=RECIRC

19c - Recirculation Valve position (feedback)

20c - Vehicle speed in kph, updating only once per second. (real speed, not speed+safety margin as in the speedometer)

21c - Engine RPM in hundreds. This too only updates once per second.

22c - ?

23c - ?

24c - Sun sensor, exterior lights switch & panel lights control (term. 58 & 58d voltage) - used for A/C panel display illum.

25c - ?

26c - ?

27c - ?

28c - Fan speed?

29c - ?

30c - Engine run time in seconds (255 max.)(=0xff)

31c - Timing counter

32c - Displays test

33c - Software version? Mine states 3.4

34c - ?

35c - Outside temp. from inlet sensor (filtered?)

36c - temp?

[Loren]

An operating temperature with the needle between the 8 and 0 seems to be typical of most cars.

The fact that your engine compartment fan is coming on could be because the compartment temperature sensor could be loose and touching something hot. Perhaps the "technician" who replaced your engine missed that part of the installation.

I'm not sure of the exact location of the temperature sensor, but there is a lot of expert help here who does.

Bill

You can read the coolant temperature in the diagnostic mode that shows on the display at the console. I use it to monitor the engine temp while driving.

Here is the info I got from Rennlist forum.

-----

To access diagnostics:

Hold down the Recirculating & Air up buttons for 5 seconds. The + - buttons go up and down through the list of "c" codes. The center vent button switches the left display between the "c" code and its actual value. Press the Auto button to exit.

I have yet to verify all these, this info was copied from wonderful people on PPBB!

Here is a list of what can be seen:

0c - ERL

1c - Oil Temp?

2c - Inside temp. Sensor mounted in the aspirator assembly at the side of the dash.

3c - Outside temp. Sensor located inside the air inlet of the A/C unit.

4c - Outside temp. Sensor located in front grill of the radiator. The data is fed to the Climatronic from the instrument cluster. When not moving, the instrument cluster OBC temp display retains it's last setting until moving. This is to prevent heat emanating from the radiator affecting the temperature sensor. The A/C unit uses the lower of the two outside air temp values in determining fresh-air temp.

5c - Outside temp. (matches OBC outside temp display)

6c - Coolant temp.

7c - Footwell discharge temp.

8c - Sun sensor (dash top)

9c - Sun sensor.

10c - Passenger compartment fan speed.

11c - Passenger compartment fan voltage.

12c - Temperature mix Flap command 1=COLD, 100=HOT

13c - Temperature mix Flap position

14c - Central Flap command

15c - Central Flap position

16c - Footwell/Defrost Flap command

17c - Footwell/Defrost Flap position

18c - Recirculation Valve command 1=OFF, 100=RECIRC

19c - Recirculation Valve position (feedback)

20c - Vehicle speed in kph, updating only once per second. (real speed, not speed+safety margin as in the speedometer)

21c - Engine RPM in hundreds. This too only updates once per second.

22c - ?

23c - ?

24c - Sun sensor, exterior lights switch & panel lights control (term. 58 & 58d voltage) - used for A/C panel display illum.

25c - ?

26c - ?

27c - ?

28c - Fan speed?

29c - ?

30c - Engine run time in seconds (255 max.)(=0xff)

31c - Timing counter

32c - Displays test

33c - Software version? Mine states 3.4

34c - ?

35c - Outside temp. from inlet sensor (filtered?)

36c - temp?

This does not work on MY01 or newer cars.

The HVAC stuff may be accurate but if you want accurate readings on engine sensors etc. use the Durametric software, a PST2 or PIWIS tester.

[w8vnf]

Howdy All

No one has mentioned altitude. I can guarentee you that from 6300' to 9100', your temperature guage is going to be above 180. This is especially true if the AC is on.

Bernie

0716102148 MST

[Loren]

Howdy All

No one has mentioned altitude. I can guarentee you that from 6300' to 9100', your temperature guage is going to be above 180. This is especially true if the AC is on.

Bernie

0716102148 MST

The boiling point temperature of water is 195.315 °F at 9100 feet (Altitude Corrected). So I would expect it to be less than 10 degrees (F) higher.