Antifreeze Condensation on Deck lid
 

I changed my oil this past weekend, and when in the trunk this AM just to check the oil level again, I noticed there was some condensation of Antifreeze on the trunks lid. It was in the pattern of the rubber gasket around the holding tank. I checked to make sure the coolant cap was tight, and it was. When looking under the plastic cover that hides the relief valve, I noticed a very small antifreeze residue around the lower part of the valve. That area was not wet with antifreeze. I was able to snug up all the bolts around the valve approx. a 1/4 turn. Not sure but maybe a new coolant cap is needed.

I'd replace the coolant cap and the O-rings on the vent valve. Careful tightening those bolts btw, because they strip the plastic easily or break, and then you're in for bad day.

1. Make sure your coolant cap ends in .04. If not, consider replacing.
2. The bleeder assembly has a couple of O-rings that may need to be replaced. Very easy DYI with instructions available online.
3. For some of folks, like me, your results may vary. My take is that's why that area is sealed from the trunk to begin with.

You may want to pressure test the system to rule out any other leaks.

I just asked my Porsche indy shop about this, as mine does it too. They said that they see it on most Boxsters, and don't worry about it. Mine has the updated 04 coolant res cap.

I am going to watch for any more condensation under the deck lid. The updated 04 coolant cap will be the first thing I replace if I see more condensation.

I read this in another post today about Overheating.

"The purge valves can go bad as well. Though these typically lead more to condensation on the trunk lid."


Which is what I am seeing.

Here's what I did to isolate the condensation issue.
Take off the Coolant cover plate.
Place sandwich baggies over the purge valve and the Fill cap
Then place clear plastic wrap over the top of the tank.
You will then be able to see which one is creating condensation.
For me it was purge valve. I replaced the 2 'O' rings and cleaned up some sloppy sealant in the purge value assemble and WALA - no more condensation issues

Very Smart!

I did the above and got the engine coolant up to 180 degrees. Will let the car sit in the garage a while and see what turns up.....

I checked for antifreeze condensation in the small plastic bags over the coolant cap and relief valve after the car sat for several hours in the garage. I only see a small amount of sweating in the bag that's on the coolant cap. I am thinking the earlier antifreeze condensation may have come from the coolant cap not being tightened completely....Hope so anyway! I will continue to monitor for Antifreeze condensation on the deck lid.

After a drive today I found more antifreeze condensation on the deck lid. Now I need to find a decent price on a coolant cap.

Just last week i had a coolant cap fail, and thought my car was down for the count. I thought the head cracked, the water pump went out, or the tank cracked. $7.99 for a coolant cap, and all is well. If its leaking, dont push your luck, replace it before your engine overheats and dumps 3 gallons of coolant on the ground.

Joe

+1 Agree with the advice above. This is one a big 'shop around' item. Get the genuine .04 part and move on!

My new coolant cap (part #99610644704) should be arriving any day now from Amazon.com. With using some of my available points the $29 part only cost 19.67. Plus free shipping.....That's a big difference from the Dealer at $44 plus Tax.