300SD - running down a cylinder? - PeachParts Mercedes-Benz Forum

destroy · #1 08-19-2013, 04:53 PM

Having some trouble with my SD all of a sudden.

Last week I adjusted the valves and put everything back together as it should. When I started it up it was running like a top - haven't heard it that smooth since a time after the engine was replaced. Partly due to the valve adjustment, but I'm sure partly due to the fact that I had a couple glow plugs where the nuts had fallen off for some reason so they weren't making contact and operating anymore...

At this time I also took the spin on filter and dumped some diesel out (real clean looking stuff, not a spec of crud in there), and added some Stanadyne Performance Formula to the filter to replace the diesel and give a concentrated shot to the engine before the emissions test.

Anyway, she was running like a top so I went to take it for a drive as I was going to go get my emissions check done and renew my insurance. The trans wasn't shifting like it should - no kick down, shifting up very early. It would shift fine if you went through manually. I thought maybe I got the vacuum wrong so I pulled over and everything was fine under hood... no luck. Figure maybe I stretched the cable or something and might have to adjust that to get it back to spec, oh well... few blocks later it got ROUGH. It started running with no power at all, idling very roughly. RPM's looked normal, but the engine was rocking all over the place under the hood and had no power. It really felt like it was missing on a cylinder or two.

So, I figured I wasn't going to get it Air Care'd that day and drove it home. Now it's sitting in my drive way awaiting further action. It runs the same, revs up. You can even hear the turbo spool up when I rev the engine. Unless anyone has any ideas of some things to check, I'm thinking I'm going to have to take it to a shop in the next couple days as it is my daily driver. I do have a spare car to use at the moment, but still. I don't have a torque wrench or have much interest in pulling things that I'm going to need any one-time-use to replacement parts to reassemble.

Any ideas? Should I be pulling the injectors and then cranking the engine over by hand to make sure they're spraying or anything like that? Let me know.

Thanks guys.

kerry · #2 08-19-2013, 05:10 PM

Failed to tighten a valve adjustment locknut and now the valve isn't opening or closing? I'd take the valve cover off and check every valve before taking it to anybody.

destroy · #3 08-19-2013, 05:35 PM

I was pretty damn sure they were all good and tight, but I might go do that now since I have a little time right now. Anything is possible I supposed.

Just hope it's not like the first time I did a valve adjust in this car... had one break off and it ended up with an engine replacement.

destroy · #4 08-19-2013, 08:28 PM

All fixed!

Took off the valve cover and started looking around. Found the wire retainer that holds the rocker in place for cyl #1 had come off. It came off somehow when I was working doing the valve adjust the first time and I slipped it back on. I ended up bending the retainer back into better shape and it felt a lot tighter. Where it fits into on the rockers between the two cylinders is a bit worn and it may come off again. Guess I'll have to replace that at some point if it ever becomes an issue.

Car runs well compared to before, but still needs some TLC and a fine toothed comb.

(stock image for reference)

Turns out the trans issue was just the piece on the linkage that engages the cable wasn't lined up properly.

Two birds stoned!

Even my architectural engineer turned handyman extraordinaire neighbour has a saying... "When you things yourself... you often end up doing it twice."

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