My 126 for years now, when its cold outside and you first start it up after a few hours the belts make this noise thats not belt squeling but sounds like a "crying" or "whistling" noise and gets louder at certain rpms then fades away then comes back. It does this until the engine completely warms up then stops.

Anyone expeirence this? The car did this for years and just blamed it on the cold.

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99 C43
98 S420
99 C230K
01 C240

Most likely the secondary air pump. This is located under the alternator on the V8 cars and only runs on start up until the engine is warm. Sounds like the bearings inside are going. I had the same thing on my 420SEL and had to replace it. It is not a cheap part. Some people just disconnect it, apparently it unplugs. As far as I know it only affects the emmissions system and having it off will not wreck anything else, but if you need to pass emmissions tests you will most likely need it in working order. However, I don't think we need to test cars over 20 years in Ontario unless you're up for emmissions testing this year you may not have to do it in the future.

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

420 i know what you are talking about, its the pollution pump and yes in the summer that was disconnected due to a fluttering noise it started to make. This noise is from the belts.

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99 C43
98 S420
99 C230K
01 C240

should I have them replaced? I doubt that they are in the condition that it will snap or something.

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99 C43
98 S420
99 C230K
01 C240