Accessory drive tensioner

2009 MERCEDES BENZ E320
110,000 MILES • 3.0L • V6 • TURBO • 2WD • AUTOMATIC
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RYAN.TIM.J
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My car listed above E320 diesel starts up with a squeaking noise. I notice the tensioner jumping around. I think that is the problem. I need instructions on how to replace the tensioner, and any advice on what else to replace while I am at it. I intend to replace the belt too. Everything is original.

I did notice that I do not have the needed tool to take tension off the belt, see picture, the strange bolt head on the right. Thought it was Torx when I opened the box with replacement part but it is not.

Update: figured out the connection point for the tensioner, it is an 12 point 17mm. I still need instructions or any tips and tricks. Thanks.
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Dec 7, 2019 at 1:21 PM
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STRAILER
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Hello,

Here are the tip for the manual top help you with diagrams below to show you what there are talking about:

Squeaking noises from the belt drive

Topic number LI13.20-P-049041 Version 1 Design group 13.20 Belt drive, general Date 03-10-2010 Validity Belt drive, engine 272 and engine 273.

Reason for change

Reason for block

Complaint:

Squeaking noises from the belt drive

Cause:

Axial shifting (temperature-related) of the individual belt pulleys and guide pulleys can lead to squeaking noises in isolated cases.

Remedy:

Application of Krytox lubricant - belt dressing A000 989 36 60 (from lubricating kit A000 580 03 50) - one to two drops at each point to the inner and outer side edges of the poly-V belt. Procedure:

-Bring the engine to the operating temperature (80 deg. C) and switch it off.

-Remove top front engine cover as required to get access to the poly-V-belt.

-Apply one to two drops of Krytox lubricant to the inner and outer side edges of the poly-V belt near the top idler pulley (important: only treat the edges of the belt. If the lubricant is applied to the running surface of the belt, this can cause the poly-V belt to slip).

-Start the engine so that the lubricant can spread along the edges of the belt.

* Sufficient for 15 cars, Submit as Local Purchase - KRY00284, Qty 1, handling is included

Check out the diagrams (below). Please let us know what happens.
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Dec 8, 2019 at 5:35 PM
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RYAN.TIM.J
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Hi, the tensioner was jumping around a lot. I went ahead and replaced the tensioner and the belt, both were original to the car at 110,000 miles. The noise is gone. Job went well, but there was front cover bracket that had to be removed and inter-cooler piping and support bracket that had to be removed as interference. Getting the inter-cooler piping back on was a chore, the top bolt for the inter-cooler piping support bracket did not want to go in, but with persuasion eventually did.

The tensioner was worn out, the new tensioner was much harder to load up than the old one. Squeaking is gone.
Dec 16, 2019 at 4:44 PM
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STRAILER
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Nice work, we are here to help, please use 2CarPros anytime.
Dec 17, 2019 at 11:37 AM