2.5 16v Tappet Adjustment? Worse Case Senario?
 

When I first got my car I had the local specialist give it the once over so I could be on top of the maintenance......he picked up on a few bits one of which was he recommended a new timing chain/tensioner set up and also the tappets adjusting.

This was about 2000 miles ago. Over the past 500 miles the symptoms described (poor performance, lumpy idle, slap on start up) are getting slightly worse (although they are still minor I’m being slightly anal here!) so I thought I'd book it in for the tappets adjustment and I'd do the chain and tensioner myself afterwards.

Anyway...they say all things going well 5hrs labour plus misc parts (shims/etc) for the adjustment however....I was wondering what other things "may" need changing?

I remember gearing up to do the same job on a 535i bmw, armed with a screwdriver and a set of feeler gauges. On removal of the rocker cover it became clear I needed a new cam and valve gear!!

Last thing I want is to put it in the garage with a budget of X and find that it needs more work once stripped down and then I cant afford to get the car out the garage!!!

So, what "might" they find.......cams/followers/etc.....

What's the worse case scenario?

I have no reason to think the worse just checking. The car has 100,000 miles with a main dealer history to 89,000. Its well looked after and although the symptoms I described are present they are VERY slight....I just want the car to be in A1 condition.

Any advice appreciated

Thanks

Steve

What year?
Most of the 2.5"s have the modified chain tensoiner as well as a double-row timing chain.

Camshafts never(rarely) go bad on any 16v's.

Takes me 1 to 2 hrs to adjust all of the valves.
I do that at least 4-5 times a year on the racecar.

You MUST be very careful un-bolting & re-torquing the camshafts & the camshaft bearings.

Does the 2.5-16 have Lash pads? MBDOC do you have any pictures while you were adjusting the valves on your 2.3-16?

sorry forgot, its a 1990 model. you must be good at doing the valves, the garage i use ways 5 hrs!

Five hours does seem a bit steep. Is he running over to Betty's for lunch?

There is no big mystery to adjusting the valves on a 16v. You just have to measure carefully and juggle the shims around for the various thickness's needed. You will probably have to buy 1 -3 shims from the dealer. If you can handle a BMW adjustment, the Benz is just a bit more work since the cams need to come out. Just loosen the cam keepers evenly and slowly and install the same way.

I would worry more about the tensioner. If the chain is rattleing at start up, it could have slapping the chain guides and broken them. The top one is easy to replace, the bottom one is a !@#% and takes a LOT of work (at least several hours to just get the front cover off) to get at.

Tinker

are there any online resources for this job? i would like to do it myself but would like to read up on the subject first. thanks!

Do you have the factory service CD? You can buy it from the dealer, ebay, maybe the our host and Performance Products.

Tinker