hi there. i just bought my 2.5 16v and put it into a local specialist for a check over, they recommended a new chain and tensioner and valve adjustment.

as you all know literature for these cars is in short supply, i just wondered if maybe someone had done the job themselves and photographed it? or perhaps some resources with some exploded diagrams?

i have searched about the forum and found some bits and pieces but was after something more complete-with pictures!!! anything to help a newbie with this daunting job really?!

thanks in advance
steve.
2.5 16v

If you have access to a tool that secures the chain to the cam gears while threading in a new chain than why not. use it. Considering that you will most likely need to adjust a couple of the valves than camshaft R&R might be a better, more productive way to thread your new chain in.

Your valves are adjusted by using shims under the bucket. The shims are available in incremental thicknesses, at the moment I am unable to recall what that increment is. Measure the exact clearance for each valve with feeler gauges than record, determine if (in/out) of specification, remove appropriate buckets after cams are removed, perform appropriate math to solve for replacement shim needed to bring the valve lash into specification.


With spark plugs and camshafts removed you can feed your new chain in, than reinstall the camshafts to their basic “position.” Double check the “Basic Position(s)” of camshafts than rotate the engine at least two complete revolutions by hand to ensure you have no interference problems.

The 2.5 16V engine uses a double row timing chain that should go 150K to 200K with frequent oil changes.
However the tensioner could fail much earlier.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

hi there, thanks for your reply (and u MrCjames!) i was told i had slight chain slap on start-up and was advised to renew tensioner and chain, i suppose i may as well do the job complete while i have access to it all.

do you know of any online resources that detail the job at all, i would really like some images before i jump in!

thanks again

steve

I did replaced timing chain and guides on my 2.3-16. If I have to do it over again, I would remove the engine then replace the timing chain and guides.

It was a pain to do such jobs with the engine in the car, you can ask Tinker and a bunch of other people.

Alex