Noisey engine . only sometimes

[Rhino-Neil]

Hi. Don’t laugh . But I have a 2001 Merceds A160 auto.
When i drive it keeping the rpm under 3000 it is nice and quiet. It will stay this way all day.
But if i accelerate hard there is a loud ticking from the engine.
This does not go away until the car is left over night. The next day it is quiet again.

The ticking noise is in time with engine speed . Does not matter if the car is moving or not so cant be gearbox.
Its had a full service ( oil, plugs, Air -oil and fuel filter) it was refilled with Mercedes oil.
There is no silver colour in the new or old oil.

Could this be timing chain or chain tensioner?
I have checked the timing chain and seems to be nice and tight. I mean there is no excess play in the joints. ( i could be wrong ).

Or lifters and camshaft?
I stripped the cam shaft and lifters . everything seemed ok. no visible wear.
Cant say much about chain tensioner . it works under oil pressure so not really any way to test it. ( was told it works or not).
It does have a strong spring inside and the plunger moves freely and has good pressure from the spring.
Cant see if Cam chain guides are worn as this means taking the head off ( which i am trying to avoid doing).

The car is a 2001 Mercedes LWB A Class 160
Its got

Topic

[619DioFan]

Check the exhaust system for leaks. check for any cracks in the manifolds and check all the piping .. if it only happens above 3000 rpms perhaps you can get the car on a lift , get the wheels off the ground and run it at 3000 then you can listen with a stethascope ( would only run it this fast on a lift- would not do this on jack stands ) perhaps a weak valve spring causing a valve tick ( or loose rocker arm )

[dreamer2355]

+1 to the above post using a stephoscope.

Do you have access to a mechanic oil pressure gauge to verfiy correct oil pressure?

The mileage seems too low for lifter issues but it all depends on how well the vehicle was maintained.

Did you look for any ty

[EricTheCarGuy]

I would start by checking the oil pressure as it sounds like your problem could be related to it. Here is a link to a video that I did on finding noises that might also help.
http://www.youtube.com/watch?v=6mpNRJ7m-c8

[Rhino-Neil]

Thanks for all the help.

The noise has gone now.

I bought a stephoscope and checked all over the engine where i could get to.
The noise seemed to be coming from the back of the engine under the drivers seat (right hand drive).

i worked my way to the back of the engine checking at every few inches for noises.
found what i thought it was. so i changed all three belt pulleys and the alternator and the noise has now gone ( fingers crossed ).
its been a week since i did the work and all seems fine.
I now have a nice quiet car.
Thanks again for every-ones help.. T)

[EricTheCarGuy]

That’s good news! It would suck if you had internal engine issues but it’s great you were able to find the problem and fix it so easily. Thanks for posting your fix and for using the ETCG forum.

[dreamer2355]

Thanks for letting us know the outcome!

[Author]

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