Before I started disassembly it threw a check engine light, rough running and smells rich running. Misfire on 5 and 6 and the intake manifold pressure sensor was showing a number higher than spec at idle. I did find a cam position sensor connector may have been loose and one of the intake manifold gaskets had a tear in it (possible leak).

All of the timing marks are lining up. Once the cam hold tool arrives I'll pull cam covers to see if I can tell anything else about it.

The fault codes came up once the wife stopped (engine running at idle) after having been on the interstate running fine at around 80 mph for about an hour.

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Jim

I'm going to proceed with replacing the cam adjusters and all the chains and tensioners. hopefully it will make it another 200k miles.

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Jim

Yes the pictures show your chains are stretched enough to warrant replacement, did a car with same issue, i measure the tensioner stick out 10mm approx, thats enough, on a 278, my own 104 wagon engine with 225 k miles showed 12 degrees stretch, had low torque but high reving power , after changing it lots of torque returned

I had a good day on it today but unfortunately found the #6 cyl intake cam lobe closest to firewall worn. I'll get the passenger side valve cover off tomorrow.

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Jim

I stay on top of the oil changes using Mobil 1 0W40. This engine has 253k miles on it averaging between 70 and 90 mph for most of that time. I've been changing oil at around 7500 mile interval.

rear lobe on #6, or last lobe on intake, bank 2.

This was only lobe like this. I wonder if a failing cam actuator could possibly have caused low oil flow to this lobe?

I meant to mention this is not that much of a job but there is a lot of stuff in the way that has to be removed to get to what you are working on.

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Jim

Cyl 4 also had issues with the cam lobe/roller. I got the front timing cover off and it looks like I am going to need to pull the heads to replace timing chain/guides. I would have come out cheaper finding another good, used engine.

This engine makes me like the 1998/99 E300 m606 that much more.

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Jim

I've been reading a lot of stuff about the 276/278 and was disappointed to find out that the oil pump is manipulated. I've never been a fan of variable flow oil pumps and have seen cam issues on BMWs that had this set up. It is done for energy savings is what I understand.

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Jim