Coolant tank leaking only one driven hard - 986 Forum - The Community for Porsche Boxster & Cayman Owners

jcslocum · 06-23-2017, 04:33 AM

The valve opens and closes while driving under pressure. Keeping it UP for a few days allows the air trapped to move up into that tank. Parking the car rear end high is helpful. It's a big loooong system that needs time to burp.

You need to know if there is a thermostat in there. It slows the flow of coolant down so it can shed the heat to the air. No therm can equal overheating when revs are high.

Have you cleaned in front of the rads between the AC condenser and the rads??

Gilles · 06-25-2017, 06:37 PM

Quote:

Originally Posted by jcslocum

The valve opens and closes while driving under pressure. Keeping it UP for a few days allows the air trapped to move up into that tank. Parking the car rear end high is helpful. It's a big loooong system that needs time to burp.

You need to know if there is a thermostat in there. It slows the flow of coolant down so it can shed the heat to the air. No therm can equal overheating when revs are high.

Have you cleaned in front of the rads between the AC condenser and the rads??

"On my car the water pump got replaced a couple of months ago and recently I noticed that the water level was over the max level (Cayman), and yesterday moved the clip on the bleeder valve to the upper position as I may have an air pocket on the system, so I will drive it like this for a couple of days."

Update:

Well, I left the valve open for three days and the water still reminded at the same level (over the max level..) in other words didn't help to burp the air pocket.

Yesterday, I decided to run the engine a little harder for a while (since I live in the densely SoCal area, I ran in the freeway in 4th gear at about 4500-5500rpm for about 1/2 hour) but this time I moved the heater lever to the 'Max' position with the windows open as the outside temp was almost 90 degrees.. since I left the engine cover off (Cayman) you can imagine the noise and the heat inside the cabin and when I made it back home I noticed that even if you moved the lever to the closed position the valve was left open (no difference with the clip up or down) and this morning, after letting the car cool overnight I checked the coolant level and it was back between the Min and Max tabs (the way it's supposed to be)… Running the engine at higher rpm's with the heater fully open did the trick.. :-) I am happy that it's back to where it's supposed to be :-)

PS: Another thing that got my attention while running without the engine cover was the fact that the engine gets much louder as soon as you close the throttle and Not during hard acceleration (I have the IPB intake plenum with the GT3 throttle body), the sudden noise reminded me of the turbocharged engines that suddenly close the over boost valve..

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