M119 bad valve tap - PeachParts Mercedes-Benz Forum

johnflight1 · #1 06-20-2011, 06:39 PM

1996 sl500 M119 eng has a very bad valve tap,so the first thing I did was remove the valve covers and inspected the oil tubes and they are all good both sides . I thought this was going to be an easy fix! Not so I guess?? I read many posts and have found these engines to be very solid. The cams and lifters look ok nothing really abnormal any sugestions?

johnflight1 · #2 06-20-2011, 10:54 PM

Put the valve covers back on to check it out. The tap is intermitent comes and goes and is isolated to the rt side (drivers side). When you punch it it goes away for a while and slowly comes back and sometimes goes away on its own???

mbdoc · #3 06-21-2011, 08:23 AM

With the valve cover OFF did you have someone operate the starter & look for oil "squeezing" out of the ends of the oilers?

IF that is good?? then possibly the chain is stretched OR the tensioner has failed.

Did you look at the basic cam timing to check for stretch?

Pili380SL · #4 06-21-2011, 10:00 AM

mbdoc, I find your response interesting. If the valve is depressed against a spring by the cam lobe, how can a tensioner or stretched chain cause a valve tap, unless you think maybe a loose chain/tensioner noise is being confused with tappet noise?

johnflight1 · #5 06-21-2011, 05:02 PM

I recently had the heads off for dtc p0410 had to clean the exaust ports of carbon (bad design),so you know I did mess with the chain and removed the tensioner. It ran good for a couple of weeks. Now today it is as quiet as a church mouse again. Could I have gotten some debris in the left head where the oil flows to the lifters? Could it intermitently block a lifter from oil??? It is only the left side for sure and it sounds like only 1 tappet.
No Doc sorry now I did not ck for leaks around the oil tubes could be a bad O ring maybe. tubes did look good no cracks and ends were all on good I poked at them with a dental tool. I cant do any troubleshooting today the car is back to quiet

nulu · #6 06-21-2011, 09:40 PM

Next time it does it try to put a feeler gauge between cam and lifters to find a "loose" lifter bucket, normal hydraulic lifters wont allow a feeler gauge to fit , try like a .005 to start

johnflight1 · #7 06-22-2011, 02:35 PM

Next time It taps and I have the covers off then I will ck it out with a feeler gauge and also crank it like doc says to see if any of the oil tube o rings are leaking. Hopefully it will not do it again!!! hopefully it was just some debris from the head being cleaned out for the P0410 code