Analyze and Troubleshoot "Check Engine" MIL and Electronic Control Units (ECU)!
Ticking Noise in the Hydraulic Lifters in a 119.xxx Engine
Description of Problem
Recently my car developed a 'ticking' noise on the right side of the engine (passenger) that would come and go. It was there at cold start but would go away if taken to highway speeds with the engine rpm of around 3500 to 4000! When taken back to idle, the ticking noise usually was gone.
The picture shows a lifter used on the M119 engines. Originally I believed that the noise originated from a partially collapsed lifter. If the lifter gets 'tired', then they can be collapsed easily by hand pressure. Then the oil is forced out of it via the small oil on the side.
However, the problem can also be caused by a broken oil tube. This should be investigated first before going to the trouble of removing the camshafts only to find that it's a defective oil tube. You will not be very happy!
On the All-DATA CD-ROM, there's a MB TSB that was issued in early 1995 re this problem. It states:
In case of complaints of ticking noise from the valves or lifter area and/or low oil pressure, the cause could be a missing plug in the oil feed tube (PN 119 180 02 66) between the camshafts. If one of these plugs is missing, the oil pressure to the valve elements/chain tensioner will drop causing this complaint.
The complaint can be repaired by exchanging the leaking oil pipe and checking if all other plugs are tight. The loose plug can usually be found in the valve area or in the oil pan and should be removed.
After the repair, start the engine and check the oil pressure. It should be within specs (less than apx 6 bar).
My oil pressure usually sits around '2' bar at idle when the car is warm (80C or above). The oil pressure dropped to less than 1 bar but would go back to '3' at about 1500rpm. That should have been the first clue that an oil tube was broken but did not 'compute' at the time.
Needless to say, that after removing the right side valve cover and inspecting the oil tubes, two (2) were found to have open ends. After replacing all tubes, the oil pressure and ticking noise went away!
Talk about poor design for an oil tube! Why aren't they made as a solid piece without an end cap? It's not needed at all. The fact that it is there makes the part very susceptible to failure. And they obviously do!
7/7/10: Received a email that showing a company that makes
a "metal" version with NO end plates! Check out the link to AutoHaus of Arizona. This link is the main page that you can browse for your particular Mercedes model.
Here's the direct link to the part for my '94 S500 Coupe's Cam Oiler. Both the Mercedes OEM and Skie part are shown.
To change a pair of oil tubes (red arrows), loosen and remove the camshaft brackets (red squares) so as to slip the 'tits' on the oil tubes under the camshaft brackets. Do ONE-PAIR-AT-A-TIME since the camshafts are under tension. Then replace the bracket and tighten before moving on to the next pair. That's the way I did it.
1) Buy a valve cover kit because you will want to change the gasket and the spark plug seals.
2) Will probably need a 'breather' tube assy. Mine was like the petrified forest!!
3) Will probably need the chain tensioner clamp. If it is as brittle as mine was, it will break when trying to remove it.
Here's the direct link to that part; Timing Chain Guide/Rail .
That's should do it!
Update: I debated about whether I should report this but it seems to be happening to more cars and the problem is NOT due to a broken oil tube! It's due to partial plugging of the oil passesges from use of engine additives that contain Teflon. I, probably like you, have used these products in the past and it's been shown that these products cause the oil passages to become partially plugged causing a problem with the M119 engine's lifters. Certainly a 'ticking' sound could well be due to a broken oil tube but it can tick with 'normal' oil tubes as mine did after the oil tubes were replaced.
About 3 - 6 months after replacing the oil tubes, a lifter on the right side of the engine started to tick intermittently. The oil pressure was fine, and the tick would go away around 3000rpm with a high-speed freeway drive. When it came back, I decided to try something different.
Since it was due for an oil change, I put a quart of motor flush (don't remember the brand but any brand will do) and idled the engine around 1000rpm until the tick-tick stopped which took about 25 mins. The oil was drained and refilled with fresh oil, Castrol 20W-50 dino. After this, I used a product called Auto-RX to remove any sludge, varnish and other engine deposits that might remain.
I followed Auto-RX instructions; check the web site for details. Suffice to say, that I still use a maintenance dose (5 oz) at every oil change. The tick has never returned and my engine is 'spotless'.