audipwr1

If you look closely at sensor bet you can find manufacturing part number and buy online for 30 bucks

bovien

Sweet. I have just requested prices from Porsche in Denmark and asked, if they can check internally if they have any info on the matter (last I checked, they didn't)

Larry Cable

I was right, if you look at the PET pages for the compressor one of the switches changed p/n depending upon the version of the compressor itself:

compressor until 000 111: 997 341 964 90
compressor from 000 112: 997 341 967 90

not sure if this is significant...

I would try replacing the 997 341 965 90 sensor which I *think* is the main one, the 3rd sensor is 997.341.963.90

Rick GT3

subscribed..., keep us posted, I'm on the same boat...

JB911

Well, once I get the new unit installed I will ask to keep the old one-and then if we can find out which one is probe to failure, perhaps it can be fixed.
Wondering what water might do if it reaches the system. I never get rain on my car, or very rarely-but I do wash the car, so maybe that could be a factor. Summer doesn't help, high humidity and some hot days and nights...thanks for the pics btw

JB911

There are 4 pressure switches, no detailed images, but here are some online search results:

http://www.porschesandiegoparts.com/...he/99734196790

http://www.localpartsshop.com/oe-porsche/99734196490

http://www.localpartsshop.com/oe-porsche/99734196390

http://www.porschesandiegoparts.com/...he/99734196590

Sonnen Porsche offers discounts too:

https://sonnenporscheoemparts.com/pa...&siteid=215405

JB911

Also, would it be possible to insulate the coolant pipes or the unit to protect it better? Perhaps aluminum shields or wrapping the pipes?

Thanks again

martinkm

The thermal switch in the writeup I sent caught my eye because as far as I know, the PET doesn't list a thermal switch among the replacement parts. It may be a polyswitch that resets itself over time and so Porsche thought it didn't need to be replaceable. In any case, I'd go looking for that as it might explain why so many dealers were replacing the entire assembly vs. one of the pressure switches. I doubt the OP has a pressure switch failure because his unit was saying "LIFT FAILED" and refusing to do anything...

JB911

The last time I used the lift, I heard the swoosh sound of air being released, so that could be a clue.
There are other threads, someone I believe in Spain who had a switch replaced and unit working properly as a result. So details are much appreciated

bovien

Thanks!

Thanks. Sadly i'm in Denmark an all sites I find online are US. Purchasing, shipping and tax usually isn't a viable option. I need to go to Mr. P

Mine does lift but never show "lift" in the dash. So either the pump isn't producing pressure enough to lift to the set point or a sensor is failing.

Might be worth looking at, but I'm sceptic on the issue of heat and I'm thinking the design of the pipes being some sort of aluminium under the car is due to them needing the cooling that provides against a rubber hose?
It just seems so incredibly badly engineered if the switch cannot take the heat of 200 degrees water running in a pipe 10 cm from the sensor.

JB911

Before mine failed I was getting inconsistent Lift on the dash, sometimes it was lighting up, sometimes not.

So I expect my part should be arriving soon-if I get to keep the old one I will take detailed pictures. I'd like to be able to fix it in case there's another meltdown in the future

I usually fix my own stuff when possible-
My '74 H2 has an amazing CDI ignition, but one of the 3 pickups by the crank had failed, and the rectifier has also failed in the past-I've diagnosed it mostly by replacing the pieces with a known working spare, when there's no other way

I've owned the bike for 20 years and have rebuilt the engine many times, recently a crank, and all new transmission bearings.
But electric and electronic stuff is always a nightmare

Determining if one of these pressure switches is more prone to failure would be nice-I doubt they can be returned if you buy all 4 and sort it out through the process of elimination-

Parikh1234

My car makes that whoosh sound as well sometimes!

Kobalt

Nice bike, brings back sweet memories. Never own one, never driven one. Our neighbour had one with a third party exhaust system which made the bike sound even better.

Larry Cable

agreed!

JB911

Spoke to the Service Manager today, still no ETA on my unit-
Surfed around the 991 forums, there are some cars that had the whole unit replaced-earlier on this thread someone said the unit or parts might have been upgraded from a certain serial number up-so maybe the new unit is being assembled or something, since Porsche outsources to the company that makes them. The PET shows a different looking unit for the 991 cars-who knows, maybe the 991 unit can be installed on the 997s???