"02996ttx50

Looking for some advice before a throw a new t-stat at this issue, obviously hoping thats all it is. My buddy says he think's its one of the Rad Fans failing but i THINK? i can hear them BOTH when HOT.

my temp gauge like everyone's usually sits at 180 and never deviates, but lately it's has been ticking upwards noticeably to about the 185 and even touching 190 if idling in high ambient outdoor temps. Then when I'm cruising light engine load downhill ( or into a cooler pocket of the canyon) or even free way cruising say 3k rpm, it nearly immediately it goes down and settles right back to 180.

Just r&r'd a water pump and coolant levels perfect and rads are screened in to minimize debris buildup! It has been north of 100 degrees ambient out. but still....

any thoughts? if i DO throw a part at it, let it be a $40.00 T STAT but thinking a failing rad fan as well except i for sure heard drivers side and THINK(?) I can hear passenger side! ? anyone ? Thanks in advance.

Carlo_Carrera

JMHO but those temperature fluctuations sound completely normal given the high ambient temperatures.

s65e90

Minor variations in the gauge sound normal. It's not really exact with its hash marks.

"02996ttx50

thanks for the replies gents. but. it's my second 996T in over ten years. never once seen a gauge hit 190? anyone ever have this issue?

it is NOT "normal" so something needs to be addressed. its a fan or a t-stat or a... ??

again. who here has gauge fluctuation of +10 degrees and thinks that ok?! i have never seen my gauge move over one tick above 180. until now.

Third-Reef

Mine does that if I turn the AC off while moving slow. When the AC is on the radiator fans run continuously and it always sit at 180, turn it off and it creeps up a little until the fans turn on from the coolant temp.

"02996ttx50

wow, ok.. thank you third-reef. i've been leaving the a/c OFF in an attempt to self diagnose this stuff. by letting the motor heat up. i will report back, especially if i am a suddenly(!?? ) an idiot.

thanks for that.

Carlo_Carrera

Mine does this too.

s65e90

Change the T-stat, sure, but the point is that gauge should not be used for anything more than a quick reference. You can't see 5-10 degree swings on it. Barely. I'd consider the thermostat if you feel it's old (I even had a brand new one fail upon install, bad from Porsche), but more importantly, get a real reading of the water temp.

garrett376

If you put your hand in front of the front tire in the wheel well where you see the vent in the fender liner you will be able to feel if there is air blowing versus trying to hear if the fan is working. When it's running with the AC on, it is easy to feel the air blowing when it's working.

s65e90

After reading again, you changed the water pump but didn't change the t-stat literally right next to it?

fpb111

911mhawk

Totally normal temperature gauge reading from my experience in 90 ° ambient however you can check through a durametric or another obd tool to get a second opinion on the gauge. Does seem odd to skip doing it while you were in there, maybe do it when the ps unit fails if it hasn't already.

coffeehead

FWIW, also normal for mine on hot days with CSF rads, K24's, and 1 bar tune.

"02996ttx50

thanks very much for the replies/info. no, i did NOT r&r the t-stat and i would have had i been doing this with my pcar tech friend. but i had to actually go to a SHOP for the water pump as the imminent failure of the pump ( some of you know that SOUND ) wouldn't allow me to safely drive the 60 plus miles to my friends to DIY the pump. i'm surprised in hindsight that the shop didn't suggest a new t-stat. they DID bend me over for 3.5 hours labor when TWO of my indie buddies that work on these daily told me that water pump r&r is a TWO HOUR job. so. what else is new? a shop doubled! the billable hours for BOOK TIME

so.. near as i can tell the fans DO work, but i have also been attempting to self diagnose this and mostly with A/C off as i mentioned. probably unwise. i'm gonna go run into some heat today a/c ON and see if this continues. if so add a t-stat to my current pelican parts order list.

ill report back FWIW..and again, thanks to all who replied.

s65e90

T-stat is not a bad job after the fact, but they were literally looking at it when they changed the pump and it makes no sense not to. I would also boil it when you get it to make sure it works. I've had a run of new OEM parts straight from dealer fail/ defective and it sucks to have to do it 2x. I had a brand new one fail, but at least it stuck open and wasn't an issue (it's hot where I live and never got cold). Takes a min to throw it in a pot on the stove. GL