decided to change the chain tensioner on my 86 300e, theold one doesn't want to come out is there a trick to this one as I didn't have any trouble with my 300 turbo diesel, also the oldone looks like it has a sline on the inside but the new doesn't, I got the parts from performance( impco) do I have a wrong part? thanks richard

This is from memory, because I did the job like a year ago and my book is at home, but I have a vague recollection of going through the same frustration. I unscrewed the "cap" (for lack of a better word) with a 14mm hex, and then tried to pull the tensioner out and couldn't until I reread the manual and grasped that what you are describing as a "spline" was a star shaped head that receives a 17mm hex driver and actually unscrews the tensioner itself. Got it? The star shaped part you're looking at under the cap doesn't *pull* out, it *unscrews*, with a 17mm hex wrench.

thanks, I couldn't find the info anywhere I will try this

This info is in the MB Service Manual for the 103 engine. I bought one from books4cars.com, which was pretty expensive (like $80, I think) but I would not have tried the cylinder head R&R without it. Later, I bought the complete manual set for the car on CD which included the same manual. I think the CD's were like $150.

The manual does have significant caveats about how you need to push the plunger all the way through and then restart it back through again (to back the adjusment off all the way so it can ratchet back into position), and even goes into painstaking detail how you're supposed to do this in place -- by putting in the outer sleeve into the engine first, then pushing the plunger through that.

Since you said you did the tensioner on your other car, I assume you're familiar with that drill. If not, I would guess it is discussed on this forum somewhere.

Have fun, and if you're going to do a bunch of work on that motor, I highly recommend the MB book, even at $80.