997.2 Coolant Levels
 

Waxing a few weeks ago, I noticed the coolant level in the reservoir in the engine bay was below the minimum line with the car sitting in the garage (so the back end of the car was already slightly lower than the nose, which, if anything, might make the reading higher than level).

I asked the service department and they said for that small amount, just top it off with distilled water and watch it. So I did, added about 1/2 to 1 cup of distilled water to get the line midway between the min and max marks. Then I drove the car about on a hot Sunday afternoon and much to my chagrin, found coolant dripping down from the engine later... apparently ejected from the cap via its pressure-release valve. So now the level has reset itself to just under the minimum mark.

Is this just normal for the 997.2 or 997 in general? If so, then should he minimum mark not be lower? I take a minimum mark to mean, if the level goes below this, add to bring the level above the mark.

I don't see how driving around in 90 degree weather should cause the system to over pressurize or otherwise exhaust coolant.

Not normal. Could be you just need a new cap or a new water pump. You can trace the leak to its source under the car. My hunch is water pump.

While you're poking around, check your serpentine belt pullys for grooves. These should be flat and if you discover any grooves in them, this could be contributing to the symptoms you've noted.

HTH

The overflow reservoir cap must be tightened very well. Finger-tightening is not good enough. PAG has been having trouble with the overflow tank and tank since 1999.

I had the same problem. Cap looked fine, and was well tightened.

I replaced the cap and no more leakage.

I don't understand WHY Porsche continues to use that blue cap. They seem to have problems. Always check for a white crusty film on the front bottom edge of the cap when it's on the tank,--if not there, the cap is probably fine. If there, that's a sign of a failing cap.

They should be routinely replaced when showing that film. Secondary,--the water pump. Always remember, Porsche for many decades was a OIL AND AIR COOLED manufacturer!

I'm pretty sure its coming out at the cap and not from the water pump. The reservoir has a catch basin around its edges below the cap, that routes liquid to a drain line that goes down to the road. Where the drain line ends is where the coolant ended up after I had refilled it and driven a bit. The catch basin had signs of coolant in it (the white dust) that could not have come from the distilled water I had topped the reservoir off with. Back to the dealer I guess. Stupid blue cap. Maybe I'll get them to replace that pen holder assembly in the glove box at the same time (snapped off one of the 4 fingers when inserting a ballpoint pen months ago.. whats up with that design?)

I had this same issue on my old 986. Even with a newer cap it would still register below minimum. When cold. If I did what you did and topped it off, after driving around and the car getting up to operating temp.. when I stopped the car would purge coolant.


So, when it was cold and at minimum, I would take the car out, once it was warm, I would park and check coolant. Low and behold, it was at a proper level.

Try checking your car when its cold, if its min, then drive around to get the car up to operating temp and recheck.

Weird.

Same thing here, called Suncoast and got a new cap….problem solved. Comparing the two caps, the old one's rubber gasket in the cap was used and too compressed to seal properly. THe new cap gasket was pliable and thicker.

Given the vast capacity the system has, I think it's odd that the difference between fine and low is a few ounces. Mine is a tad lower than low, and I have just left it there. No issues.

Mine has been doing this since I got it in 2007. I did replace the cap once. I think it made a difference, but not quite sure. The coolant has never gotten much below the low line. And I've never seen coolant leaking from the pump or anywhere else except a white crusty film from around the cap. It seems the car just prefers to be a little low. Very strange but never cause any problems.

It's unlikely you would ever see evidence of a leak on the garage floor either since the plumbing from front to rear has the protective under chassis covers between the hoses and the ground.

My 997.2 had coolant disappearing very slowly for a number of months but I couldn't find it. When I took the airbox off to switch to an aftermarket intake I noticed a lot of crust on the hose fitting just a few inches under the oil filter housing. I guess it was so slow it would cook off before dripping.

Dealer replaced the hose and associated hardware under CPO and the leak was solved. Granted it is likely something else for you, but it isn't too hard to slide the airbox out and take a peek at that hose connection if the cap idea doesn't pan out. If you see significant crust buildup that's it. Note that the service adviser said a little crust won't result in CPO coverage since it isn't considered abnormal.

Sorry to bump such an old thread, but I'm having the same issue as the OP and was hoping that someone who may have read this thread from years back or experienced the same problem found the solution.

My situation is virtually identical. I have a 2009 997.2 C2 that I just picked up a few weeks ago. Mechanically the car is in great shape, runs strong, and I even have service history where the water pump was just replaced less than 5000 miles ago as I know that is a common problem.

I decided to clean up the engine bay and check the oil level this past weekend and noticed the coolant level was just a few millimeters below the "min" mark. I had not seen any leaks, had any warning lights and had not had my temp gauge register high, so figured I'd just top it off to halfway between min and max and get on with it. At the Porsche tech's recommendation at my local dealership, I just used a little distilled water as opposed to putting in more coolant. After the next drive (in 85F weather) I noticed a dripping and the tell-tale smell of coolant when I parked back in my garage. I looked, and sure enough, coolant had pooled up around the cap area and was dripping down from there on to everything, including my exhaust piping. The level was now up above the max mark. I cleaned up everything and went on another drive the next day, and more had pooled up around the cap and was dripping down, but it was less than before (not enough to pool on the ground).

This morning I noticed that my coolant level is back below the min mark again (I guess everything I added purged out and burnt off). I ordered the newer cap and will be replacing that before I go driving again, and HOPEFULLY that solves the problem. I was not having any issues at all until I decided to top off the fluids. Now I'm wondering if I should have just let it sit a few ticks below the min mark and left well-enough alone.

It also seems my leak is coming from the cap, as I see no other signs of coolant loss from anywhere else along the system, and the stuff pools up in that little area around the cap and then runs off from there. If this is a simple fix due to a new $30 cap, that's fantastic, but of course I'm worried about something more extensive.

I'd continue to watch for level changes but I'm not so quick to top off since the coolant capacity is approx. 7.63 - 8.32 U.S. gallons - the MIN line is fine for me.

I appreciate the response. Yes, my plan is to replace that cap (should be here today or tomorrow), leave the coolant level right where it is currently (which is now a mm or two below the "min" mark) and then drive enough to get the temps up. If I don't have any evidence of a leak after that, I will just continue to watch my levels and temp gauges, and leave well enough alone.

It's just weird... there were no problems at all until I decided to top off my coolant. It was just fine for hundreds of miles with the level just below the "min" mark, no leaks, no temp problems, no warning lights, nothing. I thought I was being proactive by topping it off, and as soon as I did that, the leak and drippings all over my exhaust and pretty much everything underneath the reservoir started. I'm really hopeful this was just the case of an overfilled tank and a faulty cap and nothing more serious. Heck of a thing to happen within my first 2 weeks of ownership!