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Been driving my 991.2 GTS just fine but then this morning the water temp just skyrocketed >250 F. I immediately turned on the heater but no hot air. Luckily I was not too far away from home but had to stop and let it cool down and start back up several times as the temps were climbing high. The oil temperature was still normal luckily.
Coolant level is good. Did see some residue of a very very small leak at the center water pipe underneath the engine but not enough to drop onto the floor.
Is my thermostat stuck? I just installed sport cat yesterday and drove for 20 miles and it was fine. Did I maybe touch something in the process?
In regards to the infamous COV, I checked the PSE valve and seems to be operating correctly (opening and closing, I can feel more air and less from both tailpipes and sound of course).
I actually unplugged both PSE vacuum hoses and replugged it back. Both were on there pretty tight before I did this. However, I did notice that I did not snap the passenger side hose into one of the small bracket / holder, so I snapped it back in. Not sure how this would cause anything though. I also followed the vacuum hose up and wiggled it around to see if it was loose upstream, but view was limited and seemed connected.
Are there one of each cross over valves for the coolant shutoff and heater? Can't imagine both being unplugged.
Anyway, once I unplugged and replugged the PSE vacuum hoses, the problem went away. I drove for 45 minutes total throughout the day, going to the gym, disappointing a kid in a fart can of a car, etc. In other words, I was really getting on it to duplicate the issue, but the water and oil temp was at a cool 194-196 F (while in sport mode). In normal mode, the oil temp rose to 226 F but water temp stayed at 196 F. Did I let any trap air get out when I unscrewed the coolant resevoir cap?
Even though the car runs OK now, it's still troubling since I haven't found the root cause and hate to drive it too far out.
Sounds like your coolant shut off valve did not open.
That seems to be the case as another person stated that in rennlist. Do you know where it’s located on 991.2?
Saw a diagram for 991.1 but don’t know if it’s in the same location.
Is it right above the passenger side PSE vacuum line? I took a snake cam there and saw a T connection and a long thin plastic line going towards the center. Can these be easily kinked? At least I hope that’s the case since I did wiggle the PSE vacuum line a bit and snapped it back onto a small bracket right above the PSE valve.
The vacuum lines on these cars are truly pathetic.
I removed my bumper and properly fixed all the lines to the COV's with heat resistant tie-wraps on my 991.1 because they simply slide off far too easily.
Every time one goes in there, the chances of something getting bumped or stretched is pretty high.
Thank you so much! Is this easily accessible after taking the bumper off? If so, I may metal zip tie all the vacuum hoses and maybe even wrap them. Also a good excuse to change out the air filter.
How long does it take to take the bumper off? Hopefully easier than changing the Sport Cats!
Originally Posted by dux
The vacuum lines on these cars are truly pathetic.
I removed my bumper and properly fixed all the lines to the COV's with heat resistant tie-wraps on my 991.1 because they simply slide off far too easily.
Every time one goes in there, the chances of something getting bumped or stretched is pretty high.
The bumper removal is extremely easy.
You just need the correct tools and don't even need to take off the wheels.
There are tons of videos on youtube that walk you through the simple steps. Took me about 30 mins the first time, now I'm down to 15mins.
I actually ordered a BMC air filter for cheap on Amazon ($200).
Originally Posted by dux
The bumper removal is extremely easy.
You just need the correct tools and don't even need to take off the wheels.
There are tons of videos on youtube that walk you through the simple steps. Took me about 30 mins the first time, now I'm down to 15mins.
is this valve block tucked underneath toward the front of the car? We’re you able to access all 6 easily?
Originally Posted by purekoryo
Thank you so much! Is this easily accessible after taking the bumper off? If so, I may metal zip tie all the vacuum hoses and maybe even wrap them. Also a good excuse to change out the air filter.
How long does it take to take the bumper off? Hopefully easier than changing the Sport Cats!
I have a 991.1, so it's different from your setup.
With the 991.2, I believe it's visible / accessible with the removal of the bumper.
Best confirmed independently.
So it happened this morning again from a cold startup and after about 5 minutes, fans started to scream and temp started to rise 210F, but this time it did not skyrocket like before to 250 F but didn't wait either to get there and luckily I was near the gym I was going to and immediately shut her down. The heater again didn't blow hot air, although I did notice it was actually a tiny bit warm, maybe lukewarm like the COV was maybe just cracked open. The PSE valve was still operable. Anyway, I went into the gym and after about 2 hours, I came back out and unplugged and plugged both PSE vacuum lines and voila, the problem went away again. Maybe the vacuum hose has a gap where let's just enough air through to have this issue?
Going to disconnect each PSE hose independently and see if I can repeat the issue. If so, then I'll buy some metal zip ties and secure them on the PSE nipple as tight as possible.
What a pain.
You could have a funky COV, a loose electrical connection or a kinked hose (which I doubt).
These COV's are a cheap extra parts to have lying around.
Don't zip tie too tight so as to not damage the lines.
Keep us posted..
Yes. Water pump completely failed. COV’s flooded. My engine overheated and melted the pistons. Undergoing transplant of the motor...
j/k ; )
The shop found that the seals inside the water pump leaked into the COV block which contains six COV’s and also flooded the vacuum pump. They replaced all six COV’s, lines, water pump, and vacuum pump (version “C”.
Been almost 600-700 miles. Just knocked on wood, no issues thus far.
The lead tech told me that this has been fairly common and that the new water pump is the updated version to resolve this issue.
He also mentioned that there is a failsafe where essentially an emergency valve opens up and the water still circulates throughout the motor. The red warning and the temperature artificially skyrocketing is there just to scare folks to pull over since you are still losing your water out of the motor and eventually it will actually overheat. My oil temps never approached high limit.
Yes. Water pump completely failed. COV’s flooded. My engine overheated and melted the pistons. Undergoing transplant of the motor...
j/k ; )
The shop found that the seals inside the water pump leaked into the COV block which contains six COV’s and also flooded the vacuum pump. They replaced all six COV’s, lines, water pump, and vacuum pump (version “C”.
Been almost 600-700 miles. Just knocked on wood, no issues thus far.
The lead tech told me that this has been fairly common and that the new water pump is the updated version to resolve this issue.
He also mentioned that there is a failsafe where essentially an emergency valve opens up and the water still circulates throughout the motor. The red warning and the temperature artificially skyrocketing is there just to scare folks to pull over since you are still losing your water out of the motor and eventually it will actually overheat. My oil temps never approached high limit.
