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My 2002 CLK 500 with ~120 000 miles on the clock makes some sort of grinding noise from the front upper part of the engine, hard to pinpoint where it is coming from.
These engines are new to me so I am unsure of if this is perfectly normal or not.
Please share your knowledge if you recognize the noise/sound! Much appreciated
The grinding noise can best be heard at around 52-54 secs into the video.
I don't think I heard anything like that from both my CLK500. I think what you can do - remove the serpentine belt at all and start the engine. If you will hear the same noise again - you'll know it's coming out of the engine itself. If the noise will disappear - you'll know it's coming out of whatever is being driven by the belt - pulleys, tensioners, a/c compressor etc..
^^^ I agree - remove the belt and check it. It's OK to run the engine for a minute without the belt for checking sounds like this, but keep in mind the alternator will not be operating so all power will be drawn from the battery, and the water pump will also not operate, so it's best to do this on a cold engine.
On thing it could be is the belt tensioner pulley. It the spring in it can go bad. The first symptom is often a "clucking" noise when the belt is put under some stress, like with the AC compressor on max cooling, or loading up the power steering pump by turning the wheels hard to one side. Another possibility is the water pump or the harmonic balancer. Observe both with the belt on to make sure you see no wobbling. Of course if the sound persists with the belt removed, then it's going to be something internal, like a timing chain or valve.
I removed the belt and the noise is still there (although slightly different, but this probably does not make any sense, so I'll just ignore that for now).
- Conclusion, not the belt or any of the pulleys.
After listening closer to different parts the noise seems to be coming from this red circled part, especially from the right side - What part is that? Does it make any sense to have a grinding noise coming from it?
(I could be mistaken, could be coming from the top of the engine just underneath this circled part)
That is the "secondary air injection pump". It is used to force fresh air into the exhaust when the engine is cold and is an emissions control. Once the temperature has reached a certain level so that the catalytic converters are operating, it shuts off.
Thanks, If that's the secondary air injection pump, then that is not where the noise is coming from, since it stays on after the initial pump activation period post startup.
Probably from internally somewhere, inside camshaft housing or around that area.
09-23-2018, 05:25 AM
