I would replace it

I read some where that the rad cap part number should end in "04" ...is there anything wrong with "01" the one I have in my 06 987S?

I did notice yesterday my temp needle move a bit over 7 in the 175 mark. The overflow tank was at the Min level so I added ~ a cup of Pedro approved antifreeze. No effect to the temp gauge.

MIKELLIG

Some of the earlier caps sometimes allowed a bit of coolant to escape. Check the trunk lid above the coolant / oil cap area to see if there's any evidence of condensation. If that's the case, take the plunge and treat you Boxster to a new cap. Could just be that the rubber seal isn't doing its job any more. This would be the cheapest fix if there is a leak.

Could also be the reservoir has a tiny crack. Just keep an eye on it. At least the 987 has a visual check without having to remove the cap.

Thanks Guenter,

I think I will treat the Boxster to a new cap...so be quiet and don't let the cat out of the bag the next time we get together

MIKELLIG

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BLKBOXS
Thanks Guenter,

I think I will treat the Boxster to a new cap...so be quiet and don't let the cat out of the bag the next time we get together

I filled up to the MAX line with approved coolant and a few days later...back to MIN ummm..

I just got off the phone with my Indy to order a new cap, however he wants to check out the system...this seems to be a good idea with ~50K Miles on my 2006 987s

What will it be??

1. ..Leaky coolant cap.
2. ...crack in overflow tank
3. ...Water pump shot
4. ...something else

MIKELLIG

Quote
BLKBOXS

Quote
BLKBOXS
Thanks Guenter,

I think I will treat the Boxster to a new cap...so be quiet and don't let the cat out of the bag the next time we get together

I filled up to the MAX line with approved coolant and a few days later...back to MIN ummm..

I just got off the phone with my Indy to order a new cap, however he wants to check out the system...this seems to be a good idea with ~50K Miles on my 2006 987s

What will it be??

1. ..Leaky coolant cap.
2. ...crack in overflow tank
3. ...Water pump shot
4. ...something else

if the water pump starts to leak, there's usually a little pink "stalactite" that forms under the pump. Mike spotted it during an oil change on my 987. That was at about 55 K miles. There wasn't enough coolant loss for it to show up at the tank.

Did you find any trace of evaporation on the trunk lid in the area above the oil / coolant fillers?

If it isn't the cap, I'm guessing cracked overflow tank or there's a pressure valve that I believe can also go.

Overfilled. My info is the newer cars are even less forgiving of having too much coolant than the older models. Put too much coolant in the tank -- and having the level at the MAX line is too much -- and it will be expelled over time and could look like there is a leak.

When you check the coolant level ideally you do so with the engine dead cold and the car level. If the level is low, below the MIN line I guess, add enough to bring it over the MIN line. The level will be higher when the engine is hot. You can check the level hot to see where the level is in relationship to the MAX line. If there is plenty of room you can perhaps add more coolant *once* the engine has completely cooled.

However, just to be safe get the car checked out for any cooling system leaks.

I got my Boxster back with a clean "bill" of health.

Pressure test - Ok
Reservoir Tank- no leaks and looks good
Nice and dry under and on top of the Reservoir tank Plate.
Water Pump- I assume it is fine...I forgot to ask..I will call in the morning
Replace the coolant cap with a "04" version

I feel much better that this was check out...Thanks P folks for your advise.

MIKELLIG

The old caps are prone to errant failures, which can cause your coolant to gush out. It's not worth avoiding a $20 replacement cap.