85fortheDrive

Here's the symptom I don't get. There is no leak until I shut off the engine. Would this be due to a pressure backflush after the pump has stopped running? For all I know, all coolant leaks are like this. But it seems strange that the leak doesn't start until the engine shuts off.

Tentatively made an appt for a Tuesday drop off at the local Porsche dealer. It would be the first time the OB has ever been into a P-shop. Might have to change my name to Benjamin Dover...

perrys4

BYOL....Bring your own Lube!!

dr bob

Two things contribute to this--

First is that coolant leaks will "blow away" while you are driving. You may be leaving the same puddle, but it's a really long puddle that you don't notice.

Second thing is that the coolant circulating through the system and engine is cooler when the engine is running, since heat is stripped out at the radiator by the fnas and the moving air. Shut the car off and circulation ceases. Now coolant in contact with the still-hot block and heads will increase in temp until the block has cooled a little and the coolnat has heated a lot, to the point where they are the same. Even with no additional heat added, the coollant will initially get hotter before the whole system cools down. It's that "hot soak" condition that's often the first telltale time for leaks.

I had a similar leak for a while that turned out to be the engine end of the top radiator hose. Lower hose could do the same thing. Coolant was running down into the water pump area during hot-soak, and it looked like I was going in for a WP replace. It was also coming down the side of teh engine and over the AC compressor, similar to a head-gasket leak. (!!!) Then I noticed a slight stain where the coolant was running from the hose, and I figured out that it could be remedied with some adjustment of the hose and the clamp. I'm using the Zerex G-05 coolant which has no color added, so the 'stains' from the dribble were virtually invisible on the engine castings.

Chazz

When my radiator eventually sprung a leak it squirted a small stream of coolant toward the lower front of the engine so that the resultant drips looked like they were coming from the water pump.

Big Dave

Mine behaved the same way. Turned out that my waterpump was leaking from the pulley area. It was only visible with the belt covers off.

85fortheDrive

I tested what MrMerlin suggested and the coolant is indeed leaking down the driver's side to of the oil pan. Thus, I am pretty sure it is an internal leak in the water pump. Given my lack of time and my hopes to keep driving the car during Sep and Oct, I am going to take it to the Porsche Exchange in Highland Park.

Thanks to Dr. Bob, I more thoroughly understand where the coolant goes while the engine is on.

I will indeed bring some KY jelly.

Peace and Big Thanks,
Tim