Hi, could somebody help me, my merc 300SE,1989 model started to make ticking noise, when is on P or D or N. Seems like it's go faster while I accelerate. I couldn't here the ticking noise while I am driving. The ticking seems to be coming from the top of the head, is it the valve (that's what mechanic thinks, without even opening the rocket) or something simpler, means not so expensive? The oil pressure is ok, and besides ticking is running fine. Anybody has an idea??
Thanks Nina

Might be a faulty hydraulic lifter. How's the oil level? You might want to look through the search facility here.

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Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

Oil level it's ok, tat's what i am going to check tommorow, hydraulic lifters and rocker arm. thanks

It could be a leaking exaust manifold gasket causing the noise. Is the noise worse when the engine is cold? I recall someone with a 560SEL posting about a similar noise only to find out that it was simply an exaust leak. Good luck.

if the ticking corresponds with the speed of the cam shaft(faster speed faster ticking) then it coukd just be your valve clearence.

I agree with Mike on the possibility. It won't do much harm if it is so.

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... Kerry

126 tailed by a 203, 129 leading the pack.

my 300E had a similar noise. It was the engine shock!

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J.H.
'86 300E

Thanks very much for the advise, this site it's really great. The noise corresponds with cam shaft speed and my husband agrees with Mike and Kerry that's probably it is the valve clearance, (doesn't make any difference if engine it's cold or not). He is going to check over the weekend and I let you know. Thanks again. Nina

Nina:

Is he going to attempt to adjust valve clearance?

The 103 motor uses hydraulic lifters. In this situation, manual adjustment is not possible.

Mike Richards