IXLR8

Different design between the 991.1 and 991.2 coolant pumps. And if that is the case, why did they extend the warranty to 10 years on the 991.2 coolant pumps.

neanicu

What's different : the 991.2 has a vacuum line?
I have no idea why they've extended the warranty,maybe it's the newer car...? I don't know...

neanicu

By the way,just so that we are clear : all that the vacuum actuated water pump does is control the flow rate of a mechanical water pump. So it acts exactly as a mechanical pump except when vacuum is applied to the water pump. More on that,I suggest this video :

IXLR8

Which the 991.1 does not have. And from what I have read on Rennlist and who knows how accurate that is, they can leak from the vacuum line and then other parts upsteam need to be replaced.

In any case, no matter which series of 991, failure at such low mileages is a joke.

neanicu

It sucks coolant up the vacuum line : it shouldn't happen but it's still a simple system...most likely it either has a vacuum canister to retain vacuum on startup or a valve block that distributes vacuum or both. Since we know it applies vacuum,what would vacuum do to a mechanical pump? It slows it down in my mind...so on cold start it would move less coolant and it will warm up faster. It's for emissions : not the best design but the theory of operation is simple. Why it fails? Because the membrane(or whatever they are using) inside to slow up the impeller bursts and allows coolant into the vacuum circuit. It's just a ridiculous solution to a simple problem. Lol!

barncobob

after my 3rd pump in 50K and dealing with the dealer I had had enuff...switched brands and havent looked back,,,still hanging around till I sell my COBB..its in the parts section..

jitdc

Just had the pump fail on my 2017 C2S manual w/l 23.5k miles. Got the engine over temp warning, pulled over, and had it towed to the dealership. They called this AM and will replace it under warranty.

soontobe

folks there is a recall from Porsche ( service bulletin) for the water pump, i had mine replaced for free from the dealer. they replace the water pump and valve block as well.

jitdc

I had planned on having the dealership look at mine next week when it was going in for a scheduled oil change. As luck would have it, the pump failed early. But I would not have known it was an issue without the good folks here at Rennlist and this thread. Could have been a reason for a crummy day, but thankfully I had a sense of what the issue was and how to get it resolved quickly. Thanks!