928 over Panamera
03-30-2018, 07:38 AM
#16
Three Wheelin'
Thread Starter
The reason GDI or DDI cars cake up with crap on the intake valves is from soot from the EGR system and oil from the crank case ventilation system mixing and forming a sludge that sticks to everything.
The only real way to combat these long term is to eliminate the EGR system and or improve the crank ventilation system's oil separating ability with something like a provent.
You can also add methanol/water injection, that has shown great promise on diesel BMWs with gunk issues like the last gen 335D that need their intakes and valves walnut shell blasted every 75K miles.
Most 928s don't have and egr system ( 78-79 CIS only IIRC ) so our ports remain clean even though our crank case ventilation is poor at best causing quite a bit of oil to be ingested.
The only real way to combat these long term is to eliminate the EGR system and or improve the crank ventilation system's oil separating ability with something like a provent.
You can also add methanol/water injection, that has shown great promise on diesel BMWs with gunk issues like the last gen 335D that need their intakes and valves walnut shell blasted every 75K miles.
Most 928s don't have and egr system ( 78-79 CIS only IIRC ) so our ports remain clean even though our crank case ventilation is poor at best causing quite a bit of oil to be ingested.
03-30-2018, 10:32 PM
#17
Burning Brakes
When it comes to a modern Porsche, I think carbon buildup would be the least of my worries.
With nearly all models (not just the Cayenne) you play the "engine lottery" when it comes to scored cylinders. I recently started looking at 911s and Caymans and was disappointed to see that's it's probably worse than the IMS bearing issue on those cars.
Like most Porsches, the Panamera suffers from halfassed glued in coolant pipes that let go whenever.
Variocam bolt failures on certain years which destroy the engine, I think there's a recall on that now.
Worst case for a 928 is TB failure which is easily avoidable by checking end play during oil changes.
Maintenance on the 928 is a dream...yes there are drama queens that make a big deal out of something as simple as a timing belt or intake "refresh". I'd love to see them attempt a starter or alternator on a V8 Cayenne...especially a turbo.
My 928 is like a Rolex and the Cayenne is more of a Swatch.
I will say that if you stick with a V6, you'll probably have zero engine issues...but not much fun considering it's a 4,000+ lb car.
With nearly all models (not just the Cayenne) you play the "engine lottery" when it comes to scored cylinders. I recently started looking at 911s and Caymans and was disappointed to see that's it's probably worse than the IMS bearing issue on those cars.
Like most Porsches, the Panamera suffers from halfassed glued in coolant pipes that let go whenever.
Variocam bolt failures on certain years which destroy the engine, I think there's a recall on that now.
Worst case for a 928 is TB failure which is easily avoidable by checking end play during oil changes.
Maintenance on the 928 is a dream...yes there are drama queens that make a big deal out of something as simple as a timing belt or intake "refresh". I'd love to see them attempt a starter or alternator on a V8 Cayenne...especially a turbo.
My 928 is like a Rolex and the Cayenne is more of a Swatch.
I will say that if you stick with a V6, you'll probably have zero engine issues...but not much fun considering it's a 4,000+ lb car.
