[lowrydr310]

I was at the salvage yard recently to pick up a door lock actuator and some random vents and trim clips and came across a few E90s. I was really surprised when I saw this engine.

What do you need to do, or rather NOT do, to let the inside of your engine get this bad?

Is there any specific reason the top of the exhaust cam cover for the #3 and #4 cylinders has excess sludge buildup?

[gT-BMW]

yes. neglect thats why its in the junkyard

[Indyeah]

Sludge should be swept away by the oil and then drained at the next oil change if the engine is working properly. Ultimately could be caused by a lot of things so its a good idea to actually take all these covers off and look at significant service intervals.

[hassmaschine]

I've seen worse.

It probably still ran fine.

[Jim_B]

Aside from that one area on the left you mentioned, it's really not that bad. My wife's car was worse when we bought it. (Runs great, compression is fine.) When I changed the valve cover gasket we scraped off/vacuumed out a lot of the top end sludge.

[lowrydr310]

Originally Posted by Jim_B

Aside from that one area on the left you mentioned, it's really not that bad. My wife's car was worse when we bought it. (Runs great, compression is fine.) When I changed the valve cover gasket we scraped off/vacuumed out a lot of the top end sludge.

I guess I'm just not used to seeing anything like that. Every car I've owned has had 5000 miles OCIs or less with full synthetic oil (M1, Pennzoil Platinum, or whatever Castrol named their synetic over the years). Even my old 90 Eclipse GS-T that I bought with 100K miles didn't look like that.

What did you use to remove the sludge? I'm planning a valve cover gasket replacement soon and I'd like to be prepared if there's any crud to clean.

[Bimmer Pleaser]

here is my N52 when I did the VCG.

[tlow98]

How long has the valve cover been left off this motor? I see a bunch of rust spotting on the cams... normally only happens with the cover off.

[Bimmer Pleaser]

Originally Posted by tlow98

How long has the valve cover been left off this motor? I see a bunch of rust spotting on the cams... normally only happens with the cover off.

Took the picture right after I took the cover off to replace the gaskets

[tlow98]

Originally Posted by Bimmer Pleaser

Took the picture right after I took the cover off to replace the gaskets

Ah. Gotcha

[Jim_B]

Originally Posted by lowrydr310

What did you use to remove the sludge? I'm planning a valve cover gasket replacement soon and I'd like to be prepared if there's any crud to clean.

A small, dull (rounded corners) flat-blade screwdriver, paper towels and a household vacuum. Most of the sludge was pretty dry, so it didn't make too much of a mess to vacuum it up.