tmckenna

Hi everyone, haven't posted here in quite a while, life's been crazy and just finished up what was probably the busiest summer of my life this year.

Anyway, my 958.1 Turbo S has been leaking oil. I know the leak is extremely slow because I topped off the oil in June I believe, (5 months ago or so) and my oil level still shows to be right in the middle of the "Min" and "Max indicators. Not to mention that anytime I park, it appears to drop just 1 or 2 drops of oil, it's never a puddle.

I have an independent mechanic that is a very close friend (I fully trust him), who took a look at it and seems to believe that its the rear main seal. They checked the valve cover gaskets which appear to be clean, and they said it's definitely coming from the back of the motor. Has anyone dealt with something similar? The car has a decent amount of miles on it so I was fully aware I might run into some issues like this. Rear main seal appears to be a motor out process, and if that is the case I will be doing a complete overhaul and reseal of the motor, and catless primary downpipes, (possibly even Pure850 Turbos) so there is somewhat of a silver lining.

Just curious what your guys thoughts are?

RAudi Driver

Mine was the vacuum pump.

garrett376

Same here.

CAVU

Another possibility is HPFP failing: https://rennlist.com/forums/cayenne-...and-p1031.html

projectAM

Did either of you replace your vacuum pump at the time? I just replaced the coolant sensor that screws into the head and had to remove it to access the sensor. The vacuum pump seems to be working fine (I’m at 95k on my 13 GTS) so my plan is to just replace the 2 o-rings.

RAudi Driver

Vacuum pump is only $149 so I changed that a few years back.

projectAM

I'm thinking I'll do the same- especially since the expansion tank, multiple hoses and the false firewall (outer third) have been removed.

drdantheman1

Just had mine in for the same thing (although the 958.2 TTV6 motor) and it was the vacuum pump.

garrett376

This happened 8 years ago, but yes, the vacuum pump was changed to solve the problem.

Slickdvl

Is it near the oil cooler area? I think I have a leak as well, seems to be covering that area pretty well - it’s kinda near the oil drain
is there a diy on the vacuum pump?

RAudi Driver

Passenger side head at the rear. with the right tools, no need to remove the firewall.

sologt3

For those where the vacuum pump was leaking, did you get a burning smell?

I get a slight oil burning smell from the back of the engine, but weirdly enough I haven't gotten one drop of oil on the ground. Wherever it's leaking, it must be dropping onto the exhaust and burning off, hence the oil burning smell.

Initially I thought it might be the HPFP but since several of you have said it's the vacuum pump, I'm starting to suspect it.

RAudi Driver

The oil will collect on the belly pan. Have you taken those off and inspected?

sologt3

Yup, the belly pan was pretty clean when I took it off, which was surprising. It's the weirdest oil leak I've ever dealt with, because I can definitely smell it in the rear engine area, but it completely burns off on the exhaust manifold without anything dripping down.