Author Topic: High pitched peeping engine noise?  (Read 1494 times)

Berggreen

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High pitched peeping engine noise?
« on: September 16, 2020, 22:10:52 »
Hello,

I have noticed a high pitched peeping sound/noise from the engine for some time, which seems to get worse.

I have tried to make some videos while driving, where it can be heard. Hope you can hear it through the background normal engine sound.

https://www.dropbox.com/s/zw271ykhgkvds32/IMG_8725.MOV?dl=0

https://www.dropbox.com/s/b4gvkz1s6pxkzze/IMG_8726.MOV?dl=0

https://www.dropbox.com/s/aysdns81i54fc6o/IMG_8727.MOV?dl=0

What do you think it can be? A worn cam shaft or cam shaft bearing maybe? Or something else?

The car is a 1970 280SL, and the engine is a M130.981 with manual gearbox. Camshaft is an “05”.

Thanx,

Christian
« Last Edit: September 16, 2020, 22:21:47 by Berggreen »
02/1971 MB 280SL (aut.) - olive green 291H
11/1970 MB 280SL (man.) - silver 180G
12/1977 MB 350SE (aut.) - deep green 825H
03/1969 Volvo 1800S (man.) - dark green 94

Cees Klumper

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Re: High pitched peeping engine noise?
« Reply #1 on: September 16, 2020, 22:54:51 »
Christian - it sounds to me like the alternator bearing going bad. Something external to the engine. Maybe take off the drive belt and check if the alternator bearing is making any noise when you spin it.
Cees Klumper
1969 Mercedes 280 SL automatic
1968 Ford Mustang 302 V8
1961 Alfa Romeo Giulietta Sprint Coupe 1600
1962 FIAT 1500S OSCA convertible
1972 Lancia Fulvia Coupe 1.3
1983 Porsche 944 2.5
1990 Ford Bronco II

Berggreen

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Re: High pitched peeping engine noise?
« Reply #2 on: September 17, 2020, 11:41:48 »
Christian - it sounds to me like the alternator bearing going bad. Something external to the engine. Maybe take off the drive belt and check if the alternator bearing is making any noise when you spin it.

Thanks Cees, I appreciate your input and suggestion. :)

Unfortunately, the sound/noise is not there when the engine is cold, but only when it reaches normal operating temperature.

Thus, it seems to follow the engine oil temperature, and this was why I was thinking of the camshaft or camshaft bearings. But just a guess......and I have no prior experience of which noise/sounds are associated with a worn camshaft or bearings. But maybe you or others have? :)

Cheers,

Christian
02/1971 MB 280SL (aut.) - olive green 291H
11/1970 MB 280SL (man.) - silver 180G
12/1977 MB 350SE (aut.) - deep green 825H
03/1969 Volvo 1800S (man.) - dark green 94

ejboyd5

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Re: High pitched peeping engine noise?
« Reply #3 on: September 17, 2020, 15:52:17 »
Don't look for deep troubles where they may not exist. Remove the belt to see if the noise goes away.