I have a 91 Mercedes 560 SEL with 130K. Recently the car developed ticking noise that sounded like the timing chain was slapping on the chain guides. The noise occurs all the time when the car is in drive (D). I can hear the noise when I am driving at slow speed with the windows down. The noise is coming from the driver side of the engine just under the valve cover. There is no noise when the car is in P or N. I took the car to reputable garage where they changed the timing chain, the upper chain guides (a total of 4), and the timing chain tensioner. All of that didn't help at all; the noise is still there. I have been told that the cams looked to be in excellent condition and the noise might be coming from one of the rocker arms or hydraulic ball stud assembly. I was wondering if such symptoms occurs due to faulty lifter or rocker arms? Is it going to damage the cams if I continue driving the car ? and is there a way to check and be sure before changing the rocker arms or lifters. Any help will be greatly appreciated.


Thanks

Before you spend a small fortune... try tightening the exhaust manifold bolts... if they work loose, you'll hear a ticking noise.

Good Luck!

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Michael
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76 450SL
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United States Special Operations Command
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also have a very close look at the exhaust manifold gasket(s)- if on your model- as well the exhaust system piping/ flanges close to the motor- - that tickiing noise will dissappear if these exhaust culprits are the cause and are addressed

If it ends up not being an exhaust manifold leak, my guess would be the rocker arms. My car makes the exact same noise (103k miles) in the same location, whether it be in park, neutral or drive. I've spoken with a MB mechanic about it and he was quite certain it wasn't the timing chain/guides.

Just a suggestion. Have the torque converter bolts checked. In more than one case I have seen loose converter bolts cause the same noise and it's very difficult to pinpoint.

Thanks for all of the help. I checked the torque converter bolts, and the exhaust manifold bolts. Everything checked out ok. None of the above seems to be cause of the problem.
I will keep you guys updated once I find the cause behind the problem.


Thanks

With emergency brake ON and car in drive, do you still notice the ticking? If yes, put a timing light on it and see if the ticking is once every flash or twice every flash. This will tell you in top end or bottom end. With no ticking in neutral makes it a little tricky doing this, huh?

I will solve the tricky part by getting another person to help me out when checking the timing.

"This will tell you in top end or bottom end" Does this mean that my problem will be in the top part of the engine; Cams or lifters or bottom end meaning that I have a problem with one of the cylinders or pistons?

I must admit that this forum is great and I do appreciate all of the technical tips that I have gotten so far.


Thanks

As you know, the crankshaft rotates twice for each complete cycle of intake, compression, ignition and exhaust of fuel. Therefore, the camshafts and associated lifters, valves, etc. only actuate once during the 2 rotations of the crankshaft. I a rod were knocking, you would hear that twice for each spark plug firing. If a valve were ticking, you would hear it only once for each firing.

Thanks for all the help. I solved the problem two days ago. One of the exhaust manifold gasket(s) needed to be replaced. The problem get much worse and eventually I could tell with no doubt the cause behind the ticking noise. I changed the gaskets on the driver side and the noise is gone.

You guys were right on the money. It is disappointing to know that a Mercedes shop couldn't tell the problem while you guys ,without even seeing the car, could provide helpful hints

That brings me to a new question. The ride is my car is not that great when compared to my brother's 78 450 SE. I have been told that the ride in the 560 SEL (Due to the rear self leveling) is not that great. Is that true?

I have changed the air cells, filter, and Hydraulic fluid with little change in the quality of the ride. The problem is worst while driving in town. On the highway the car rides great. I also noticed that the passenger rear tire in not even with road while the driver side rear wheel is perfectly aligned. Any ideas?

Thanks

Yo might check your coil dpring on that side. If you park the car on level ground, is one side lower than the other. I had a broken coil spring on my back end ('86 420SEL) and it made handling lousy, especially in city driving (lots of corners) and it wandered on the highway. A new set of rear springs cured it 100%.

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Jason Priest
1999 E430
1995 E420 - retired
1986 420SEL - retired

Glad to hear the ticking noise was fixed. Regarding the ride, if it's extremely harsh, it could be bad rear shocks. My ride was teeth jarring until I replaced them. The air cells and everything else checked out A-OK. Just an idea.....

Do you still have the factory wheels on? I replaced mine with 17's and the ride got noticably firmer, around town there is a lot more feedback. If you still have the factory wheels I would suggest checking your tire pressures as a first step.

Cheers
Matt.