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

I'll be pulling the heads this week. Seems they have to come off to change out the chains, guides, etc....

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Jim

If someone could please post the torque specs for the head bolts it would be much appreciated. I've got an older copy of WIS and it does not have this application on it. I have got a newer copy coming.

tia

I'm thinking that a combination of a bad cam adjuster and a variable flow oil pump is what damaged the cam and three rollers. If anyone knows how to disable the variable part of the oil pump and could post it I'd appreciate it. I don't want my oil pump to back down for nothing.

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Jim

Finally starting to go back together.

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Jim

Got heads bolted back on this afternoon and noticed the rear lobe on the exh cam was boogered up some so I ordered another cam. I'm not that impressed with this engine. Am I being unrealistic comparing it to the 606 in longevity? I don't care if it is a gasser I would not have expected to see the cam lobes chewed up some.

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Jim

No, you're not in my opinion.

The variable displacement oil pumps are used in quite a few engines nowadays and, like you, I've always been a little queasy about their adoption.

I've noticed on the oil pressure gauges of more modern cars when at high-speed the oil pressure gauge is showing half scale readings. I kind of like looking down and seeing the oil pressure gauge at 80-90 PSI full scale readings like my 98 Dodge truck with the Cummins engine.

Of course there's no way to definitively prove the variable displacement oil pump was the cause of your cam wear, but I'd certainly say it's a possibility. When the engineers are calibrating the operation I'd guess they're more concerned about extracting an extra 2/10's of an MPG to comply with an EPA fleet mileage requirement than they are about the owner of the car 300K miles in the future.

As I recall if the sensor that measures oil pressure fails the pump is supposed to default to full-flow, maybe you could just unplug the right sensor and force it into full displacement?

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98 Dodge-Cummins pickup (137K)
13 GLK250 (157k)
06 E320CDI (341K)
16 C300 (89K)
82 300GD Gelaendewagen (54K)