Hi all,
2009 Cayman base. 40k miles. Weird thing happened today. I was driving down the highway, 2 minutes into my drive, and my "Check Coolant Level" warning came on and then the temperature gauge shot up all the way to the maximum (past 250) with the red light blinking. I pulled over, checked under the car, no leaks. No scent of coolant anywhere. Coolant cover tight. When I came to a stop after pulling over, the coolant warning went away and the temp immediately dropped back down to it's usual 175. So far the warning hasn't returned but i just went straight home.
Dry weather, about 5k RPM driving when lights came on, just had muffler swap to Carnewal GT muffler about 100 miles ago and just had oil changed 100 miles ago.

Any suggestions on what this could be? Possibly the ECU learning the new exhaust? Bad sensor somewhere? Maybe air in the coolant system somewhere from checking the levels during oil change and inspection? I don't know.

Thanks

 

Sounds like you have low coolant. I have had this happen before in my 997.2 when the coolant was a touch low. The sensor light and message came on the dash, then the temp immediately shot to max! I was, needless to say, freaked out! I think it is a function of the computer that tells the temp gauge to peg when low on coolant, but I am not sure of that. Check all around the front of the car as hose fittings can leak, check the water pump area (passenger side middle of the car) and check any hoses up to the engine and report back.

 

Thanks. Do you know if there are two coolant warnings as in "Low Coolant" and "Check Coolant" or does Check Coolant cover both warnings?

EDIT: Disregard this particular question. It appears that there is only the "Check Coolant" warning message, none that says specifically "Low Coolant".

 

You checked that the coolant tank cap was tight but didn't check the actual coolant level?

Definitely make sure the coolant is topped off. Then monitor the level and check for leaks. Coolant has to be going somewhere.
Any white smoke coming from your exhaust? That would suggest an internal leak from a bad head gasket or cracked cylinder.
Is the water pump functioning properly? That's a common part to prematurely fail on the 987. Though this would only lead to lack of circulation and overheating, not low coolant.

Whether the needle moving to red is a warning or not, I wouldn't drive the car like that for fear that it's actually overheating. Even a few seconds and you're at risk for warping the head if there's no coolant in the car.

 

 

If you're careful, you can slowly release pressure from the cap by loosening it. Just go slow and prepare for a lot of heat to vent out.
Unfortunately, that's the easiest way to check coolant level at the track and hasn't failed me yet.

Water pump could be making a whirring sound, leaking, or allowing the engine to overheat. But it seems like most people on this forum experience it leaking when it fails. So probably safe to rule that out, unless you're super low on coolant and most of it dripped out while driving.

A little white smoke from a cold start is normal, that's just condensation in your exhaust.

 

 

Top it off and drive. Park somewhere that let's you clearly see if there are any leaks.

The under panels on these cars can hide smaller leaks pretty well. If you're not hearing any weird noises or experiencing a lack of performance, then it could be as simple as a cracked hose or something.

 

Do you have a set of ramps to drive up on? By removing just one panel, you can get a really good view of the hoses underneath. Could be a worn O-ring causing a small leak and you'd easily be able to see the pinkish/whitish residue from dried coolant.

 

Unfortunately the ramps I have do not have the right clearance angle to get the Cayman on them. I just bought some coolant and will add that tonight and give it a whirl. I may take it to the service department to get looked at but certainly will if I see any evidence of a leak or if the coolant level changes after I top it off.

 

Curious how much coolant it takes to fill it up. There's not a huge variance between Min and Max in the tank. I'm also not certain how low it has to be before it triggers the low coolant light. Fingers crossed the needle temporarily going to red was just part of the warning system and not actually overheating.

Loosing a bit of coolant overtime can happen as it gets hot and vapors escape from the pressure release caps. Do you know when the last time the coolant was flushed or topped off?

 

My car did something like this after a coolant system service while I was working to purge the air.

Where did you buy the coolant? Dealer? Keep in mind it has to be mixed with distilled water 50/50.

Also on my experience cracking the filler cap ever so slightly causes the coolant to come rushing from the reservoir to the fill cap and vent out some vent hose. Makes a mess inside the engine bay and causes more coolant loss.

Before starting out fill it up cold with the 50/50 mix. Then drive until fully warm. Turn on the heat at full blast and max temp and drive around varying the rpm a lot.

Bring coolant with you for the ride just in case.

Stay close to home and keep and eye on that gauge. If it starts to climb past the halfway point immediately pull over and shut down.

Wait 15 mins and head home. Stop again if need be.

Let the car sit a few hours and check the level.

You may need to repeat this several times over the course of a few days to work all the air out.

 

Man I hope that's all it is! I just had the oil changed and I assume they looked a the coolant level as part of the inspection process, at least according to the inspection checkoff paperwork they did. Perhaps something was done that could cause some type of air in the system problem?? Total guess though, but it seems odd that I just had the coolant checked and then just a couple days later I got a low coolant alert. It seems less likely that the levels were fine and then right after checking them, a leak developed two days later. And there are no visible signs of leak and no smell, plus the temp has stayed right at 175 for the ride home, never creeping up at all.

And I read in several places about a 50/50 mix but the guy at the Porsche dealer parts counter said "No need to mix, just pour it in." So I don't know what's going on there...