ChuangTzu

I finally got the OA back from the oil I which was in the E550 when I got it. Noteworthy:

• Aluminum: 32ppm
• Potassium: 35ppm
• Water: 0%

Blackstone suggests potassium could be from coolant entering the oil system. Since this engine has ~135k miles on it, and this is a known issue, this is probably my warning to address the potential coolant:oil mixing areas. Aluminum is also high. Water is 0, which is good, but it might still be a slow leak that cooked off during the warm up before the oil was drained...

One caveat is that I have no idea how many miles/years were on the oil before I got the car, nor what oil it was. Even still, I don't expect my car to tell me anything twice, even if most of the time it's happy to do so. Another caveat is that I re-use various containers and tubing to do my oil change. I tried like hell to clean them fully but it's possible there was some cross-contamination from another oil source or from something I was cleaning with.

Next oil change I will do traditionally through the drain plug with fresh equipment.

These potential oil:coolant mixing areas are (along with associated jobs):

• The oil cooler gasket
• The crossover pipe gasket inside the main timing cover
• The radiator? (is this only for the similar problem with transmission fluid and coolant mixing? Probably should do it at the same time anyway...)
• Do all the turbo cooler lines at the same time
• Do the water pump, while I'm in there?

I'm sure I'm missing something. Can one of you gurus remind me?

S-Prihadi

Oil Analysis I believe need at least twice or more to see the pattern, but it will be more for metal wear.
But if potassium is there and if that indicated coolant , damn....

https://www.machinerylubrication.com...-potassium-oil

These potential oil:coolant mixing areas are (along with associated jobs):

• The oil cooler gasket <<< YES YES
• The crossover pipe gasket inside the main timing cover <<< YES , this is a BIG JOB
• The radiator? (is this only for the similar problem with transmission fluid and coolant mixing? Probably should do it at the same time anyway...)
• Check your radiator, it could be a stand alone radiator for coolant only like mine. Easy to see, where does the tranny oil hoses goes to ?.
• Usually if shared with radiator, it will be on the right side of the radiator with 2 small tranny hoses.
• Radiator is the last layer if from bumper to engine bay and the first layer if engine bay to bumper. Easy to inspect all hoses to it.
• Do all the turbo cooler lines at the same time << M278 is weak on its cooler turbo lines, plastic mix with aluminum and the plastic always go first.
• Do the water pump, while I'm in there? Good idea

Wish you solve your issue fast.

ChuangTzu

Thanks man!

Blackstone wasn't sure the Potassium was from coolant. They listed some potential other sources, but I know the car better than they and I think the clock is ticking.

I forgot to mention that of course I will get the guides, tensioners, and the two cam adjuster magnets that I haven't been able to reach yet. And of course the timing chain itself... The job is so big that it seems like it would be smaller to remove the whole front fascia and frame cross member to just get full access to the front of the engine. No sense in trying to do a job that big with 6" of clearance. It's one thing to try that kind of stuff on almost any other car, but the size of the engine with turbos and the number of tubes and pipes on this thing....

This means I need to get the Porsche on the road so I have a car to drive for a week or so while I grind through this...