Coolant Temp?

[onefastman]

I have read around and found a variety of responses as to what is a normal coolant temp. My expierence (none with water cooled p-cars) has been with air cooled 911's, and bmw's. All of my bmw's have the needle in the middle, always. My 98 boxster is in the middle of the 180 and the next tic up all the time, sometimes just a bit hotter. I am running a 15w50 oil as well. The temp doesnt change in the weather I have driven it in (50-85F) nor does driving style change it (crusing at 75 or wot for extended periods).

Is this a normal operating temp?

If not, will a lower temp thermostat help or maybe flush my coolant?

Thanks for the advice and reading!

PPW

[fullthrottle52]

Mine is exactly where you describe. rarely moves a little higher when air is running and idle for awhile. completly normal I'm told.

[SoK]

Mine runs just a tic over 180

[Snowman]

I've seen that 180 degrees mentioned all over this forum. Regardless of temperature outside, length of trip, or style of driving, mine has never been anything other than maybe a needle-width above 175. Should I be concerned?

[JFP in PA]

First of all, you need to recognize that the dash gauge is woefully inaccurate, as well as non linear. Secondly, when most of these cars are showing “180” on the dash, they are actually more like 205-210F (the OEM thermostat is not fully open until nearly 200F). You can verify what temp your car is actually running by hooking up a decent scanner and checking what the real water temps are when the dash says 180F.

The 160F thermostat is an excellent mod as it will lower your actual water temps to the high 170’s to mid 180’s on an average day. More importantly, it will significantly lower your oil temps, which these engine’s sorely need……..

[SoK]

have a link to that specific thermostat? Thx!

[thstone]

Your temps are typical.

Primary reason for Porsche running the temp where it does (a bit on the high side) is to burn water out of the oil which allows them to recommend longer oil change intervals.

Further to the info that JFP noted, if the coolent never gets to ~180F, then the oil never gets near 212F and the water tends to stay in the oil.

Thus, if you are already changing oil at less than the recommended intervals, then there is no risk in using the lower temp thermostat and running lower coolent and oil temps.

[thstone]

Originally Posted by SoK

have a link to that specific thermostat? Thx!

160F Low Temperature Thermostat for Porsche Boxster, Cayman, and 911 Models

[JFP in PA]

Originally Posted by thstone

Your temps are typical.

Further to the info that JFP noted, if the coolent never gets to ~180F, then the oil never gets near 212F and the water tends to stay in the oil.

That is not completely correct. The oil system in the M96/97 normally operates under about five inches of vacuum (to afford better low tension ring sealing), where water boils well below 212F. Add in the fact that normal oil temps are always higher than the coolant temp, and the water is easily removed under normal driving. UoA's before and after going to a 160F stat have confirmed this.

[pothole]

Originally Posted by Snowman

I've seen that 180 degrees mentioned all over this forum. Regardless of temperature outside, length of trip, or style of driving, mine has never been anything other than maybe a needle-width above 175. Should I be concerned?

You car has a buffered gauge. The temp is changing, but the gauge doesn't show it.

Earlier car are not buffered - at least not as heavily.

[pothole]

Also, surely the oil doesn't need to be running beyond boiling temp for the water the evaporate off. If it's hot but not boiling, a properly long run will get quite a bit of the water out, surely?

[doragman]

my 99 with 59k has a line @ 180 and a line at 250and a line in the middle with no mark ...consistently run between the 180 and middle unmarked line ...seems a bit high ..but as mentioned earlier this might not be too accurate and I have not verfied that temp as accurate ......if it is that high it sounds like the 160 thermostat might be a good idea

[pothole]

Doragman - whatever your gauge is reading, the reality will definitely be quite a bit higher and equally definitely not lower. But your car sounds completely normal to me.

[JFP in PA]

Originally Posted by pothole

Also, surely the oil doesn't need to be running beyond boiling temp for the water the evaporate off. If it's hot but not boiling, a properly long run will get quite a bit of the water out, surely?

You are correct, but the oil still does get over 200F, even with the 160 stat. Add in the normal operating vacuum in the sump, and the water will flash off. Remember, Porsche has been using low temp stats in their "killer" engines (GT2, GT3, Turbo) for years, and the oil does just fine............

[thstone]

Originally Posted by JFP in PA

That is not completely correct. The oil system in the M96/97 normally operates under about five inches of vacuum (to afford better low tension ring sealing), where water boils well below 212F. Add in the fact that normal oil temps are always higher than the coolant temp, and the water is easily removed under normal driving. UoA's before and after going to a 160F stat have confirmed this.

JFP - thank you, I was not aware of this fact. I learn something new everyday around here!