Operating Temperature - 986 Forum - The Community for Porsche Boxster & Cayman Owners

doragman · 12-22-2012, 02:21 PM

What is the correct operating temperature for the 986 2.5 ?

.....I can't interpret the lines on the temp gauge very well, but based on the OBD scan tool reading I'm @ 210F after it warms up -- goes to 225F in heavy traffic ...I have NOT cleaned behind the radiators...yet

whatcha think ?

nnewell · 12-22-2012, 03:51 PM

My 2.5 runs at 80c which is about 175f even in the hottest weather - I think the temp. needle is straight up at that temp. Better clean the rads.

JFP in PA · 12-23-2012, 07:36 AM

Quote:

Originally Posted by doragman

What is the correct operating temperature for the 986 2.5 ?

.....I can't interpret the lines on the temp gauge very well, but based on the OBD scan tool reading I'm @ 210F after it warms up -- goes to 225F in heavy traffic ...I have NOT cleaned behind the radiators...yet

whatcha think ?

Not uncommon. The OEM thermostat is not open until around 190F or so, and normal coolant temps in the 210F+ range are common. If you could test various areas of the engine with a non contact pyrometer, you would find local "hot spots" that are much higher. Your oil is also even hotter than the coolant by around 15F.

This is why a 160F replacement thermostat is an interesting upgrade.....

mikefocke · 12-23-2012, 01:58 PM

Needle between 8 and 0 on the 180 mark of the gauge is the normal reported visual temp reading. If you don't have a history on when the radiators were last cleaned, do it. Every picture posted of the radiator debris is a horror show and it can cause damage to the radiator itself if the debris gets damp and rusts out the corners not to mention the lost efficiency.

doragman · 12-23-2012, 04:26 PM

Guys -- Thanks for the insight !

V-Rod · 12-23-2012, 07:19 PM

Quote:

Originally Posted by mikefocke

Needle between 8 and 0 on the 180 mark of the gauge is the normal reported visual temp reading. If you don't have a history on when the radiators were last cleaned, do it. Every picture posted of the radiator debris is a horror show and it can cause damage to the radiator itself if the debris gets damp and rusts out the corners not to mention the lost efficiency.

Mike,

Does the front bumper cover need to come off in order to clean the debris out? Or is there access from underneath?

V-Rod · 12-23-2012, 07:36 PM

Quote:

Originally Posted by V-Rod

Mike,

Does the front bumper cover need to come off in order to clean the debris out? Or is there access from underneath?

Answered my own question HERE, Thanks

mikefocke · 12-24-2012, 05:10 AM

Off and it is best a two person job. Prepare a soft place to sit the bumper cover once it is off so you don't scratch it.

Eric G · 12-24-2012, 06:16 AM

When the time comes, you might want to consider a low thermostat upgrade (160F). My 98' use to run in same range as Mike indicated above...since changing over to a new pump and stat she now runs just below the 1 on hot days. Much happier since I did this.

san rensho · 12-24-2012, 06:36 AM

Another thing to check are the fan resistors (ballast).If they go out,generally the fans will not work at low speed, only high. Turn on the AC and put your hand under the fan exhausts, they should both be at low speed.

doragman · 12-24-2012, 07:43 AM

thanks again -- hope everyone has a wonderful Christmas !

mikefocke · 12-24-2012, 11:04 AM

And of course you could install the center radiator and bumper cover from an S model, a larger oil/water heat exchange unit....

It is a slippery slope.

Vista glass · 05-08-2013, 02:31 AM

Thanks to 986 forum posters are in order. My base 98 temp started reading well above the 180 up to the next increment. Hmm? A search here showed the need to clean the rads. I even found a video on u tube to demonstrate front cover removal. I found a compost heap in my radiators. Wow! I removed all of that debris and constructed vent screens from aluminum mesh.

I am happy to report these screens have remained sturdy through minimal temperature range in Central Florida, triple digit speed and regular exterior maintenance procedures. I thought that would relieve the elevated temps , but not so. Back to the forum. Digital readout from the AC control panel verified the dash gauge is not askew. Thanks for that posting on accessing internal data with a few clicks of the panel. Info here in the forum helps determine that the passenger side radiator fan is not sequencing correctly. Do the easy first. Check fuses and relays as once again detailed here in the forum, all check good. So we are down to the fan motor/ballast resistor or the temp sender in engine compartment. I got an entire fan/housing /ballast assembly from someone parting out,for about the price of the resistor alone.I probably could have spliced the ballast in first to test, but rain had set in for a few days, I have a nice shop, and like to wrench so I pulled the front cover and dug in. It took a few hours as I removed parts and learned how well these machines are put together. I inspected the components revealed as the PO did not provide any records.The inspection did not find anything out of order,now I know. This job could have been done with the wheel off and the fender liner removed, but I wanted to check the rads condition with the new screens installed. It was pristine in there ! Going in through the wheel liner all I had to do was remove a support bracket,move some wires around and the entire assembly came out and the replacement back in. The bracket had to come out for me to do this .The end of the story is the fan/ballast replacement was a complete success. The gauge never exceeds the 8 in 180. I verified that indication by digital in the control panel.I have been on several 50+ mile runs at smile inducing velocity and the temp remains nominal.

Overdrive · 05-10-2013, 12:33 PM

I've found that if I can get into clean (read: open) air with no traffic in front of me at highway speeds, the needle usually sits just to the right of the line mark for 180°, even when it's over 90° outside. Since this rarely happens though unless it's the middle of the night and no one is out, I'm usually looking at the needle resting between the 8 and the 0, and sometimes bisecting the 0 when things start to get slow-moving or when I've spent a lot of time behind cars, effectively blocking off a lot of the air the radiators and right intake could be getting. This of course happens more quickly in hotter weather.

Hm...maybe this weekend calls for a little bumper removal and radiator cleaning.

teleski · 05-10-2013, 08:29 PM

I have the great honor of sitting in bumper to bumper traffic on the LA freeways on a regular basis. In that circumstance the only airflow and cooling comes from the fans running. My temp needle swings between 'splitting the 8 and 0' and 'the right edge of the 0' as the low speed fans cycle on and off. The high speed fans never kick in as far as I can tell. When cruising I regularly see straight up readings, middle to right of the '8'. This is completely normal behavior as far as I can tell. Cleaning the radiator (mine are actually pretty clean) or a low T thermostat would not change the temp range over which the fans cycle.