Coolant Leakage

[Dan Sorenson]

Coolant level goes down and the warning light for low coolant comes on. I have re filled the reservoir to the high line and the same will happen. Has any one else had a issue like this one? I can not see a leek in any of the lines. The coolant just from the reservoir will be on the ground. The temperature of the motor is about 185 to 190 not really over heating as I have cleaned all the debris from the radiators.
Dan Sorenson

[tonythetarga]

This is a bad sign. Check your oil! These engine have a history of failures called 'intermix' where oil and coolant mixes due to cracked head, broken cylinder or the heat exchanger failing. Search 996 engine failures or intermix and read up on your problem.
If your oil looks like brown or tan goo ...

[bell]

If the coolant cap is venting the coolant dumps through a tube which half the time dumps on coil #1.....
Older caps are known to prematurely vent.....replace it with the most current part number....
Yes check the oil too......
It sounds like of the coolant you are seeing on the ground is under the left rear......yes?

[LanceGT4]

Any coolant near the right side sway bar mount area or bell house?
If you see anything get an inspection camera or mirror and look forward of the A/C compressor at the base of oil cooler where it sits in on top the right side of the block.
?
On my '99 with 120,000 I had to replaced the oil and water O-rings. Coolant was weeping past the water O-rings.

You also might look up at the front under the radiators. Especially if you bumped anything with the front end.
I trusted a parking guide at an event once. I managed to bump the left front on a root. It bent the radiator mount enough to twist the radiator and break the plastic to alum seal.
Anyone need a repairable 996 radiator?

[onewhippedpuppy]

Also check the tank, they are known to leak. I've also had the coolant hose at the throttle body pop off and leak before.

[Dan Sorenson]

Originally Posted by tonythetarga

This is a bad sign. Check your oil! These engine have a history of failures called 'intermix' where oil and coolant mixes due to cracked head, broken cylinder or the heat exchanger failing. Search 996 engine failures or intermix and read up on your problem.
If your oil looks like brown or tan goo ...

Yes it is from the Left side same side as the reservoir tank it will drip out just under the left exhaust pipe. This motor was replaced at 60 thousand miles I do not have any water or tan gue in the motor oil I just hope this is not the case of starting to go bad... I only have 72K on this motor.
Dan

[tonythetarga]

Dan,
In my first post I missed the part of coolant on the ground. I'm inclined to believe that the reservoir tank is more likely the culprit. These are what Porsche refers to as 'wear items'. I'd suggest a pressure test of the system before you start replacing bits. Could be a hose as well from the reservoir or a clamp. Check the cap itself also, should be a blue cap with an -04 part number.
Tony

[Dan Sorenson]

Ok Thanks I will check the tank with a pressure test and have a look..
Dan

[FPB111]

The tank lives in a hostile environment above one of the HOT mufflers. This ages the tank making it brittle and often turning it yellow. You don't say what year yours is. The older 99-2001 have gotten expensive. The newer ones are a little cheaper.
Read this
Pelican Porsche Tech Article - Coolant Tank Replacement - Porsche 911 Carrera - Porsche 996 Carrera (1998-2005), Porsche 997 Carrera (2005-2008)

[Porsche_Tech]

If your coolant tank is not leaking it can be your coolant cap not holding pressure. also at times there is a bleeder valve on top of coolant tank that has 7mm bolts holding it down. These bolts may come loose at times.