Tensioner noise on startup?
 

I have a very loud rattle when I first start my car up. But if goes away after a couple of seconds. Very quick, loud and then it's gone. I was wondering if this may be the tensioner?

The airpump bearing grinds for a good minute and then goes away so I know it's not that. This noise is different. I also know it is not the tensioner shock because I replaced that last year.

How can I test to see if it is the tensioner? The noise does not last long enough for me to pinpoint the location. Would a tensioner going out make constant noise? Or could it rattle hard just on start up?

If it is the tensioner, what are the steps to replacing it? Thanks.

1994 c280, 85k miles

Sounds like it could be a bad tensioner. Does it do it on warm start-up or just cold?

I have has this exact problem on my c280 for 4 years now. I know it's nothing internal, as it bears none of the valve noise hallmarks and I have had my camchain/tensioner replaced with no effect. It happens cold only as the revs climb initially after the engine catching. It goes away almost immediately, but is embarrassing in a crowded parking lot. I'm guesing tensioner assembly myself, having had experience with the awful noise a bad one on my old 190e could create right off idle. If you rectify this one, please let me know how. I might try the replacement myself at Christmas if I get my holidays approved.

I had the same noise and finally pinpointed it to the belt tensioner. An easy way to identify the culprit is as follows: While the engine is running, using a broom stick, VERY CAREFULLY, push the broom stick hard against the side of the belt tensioner. If the noise stops, you identified the problem. Repeat this process with the Belt Tensioner shock absorber.

Phil

This is the exact same as me. It revs high after catching then rattles hard and the noise drops away.

Cold start especially.


I did the test before to indentify the tensioner shock, I will try tomorrow with the tensioner. But like I said, it goes away so fast I don't have time. I guess I could have my wife start it while I lean on it.

And you're right, it is embarassing..... :P

If it is the tensioner, how long could I go before it does? I would replace asap, but should I drive something else until I get the part?

Has anybody replaced the tensioner here?

Thanks. :cool:

TTT

Has somebody replaced the tensioner? Can you tell me the steps to take? Thanks.

:sun_smile

I have the same issue for about a year and its recently getting worse with the cold weather and the belt is starting to chirp faintly. I can see the shock moving a lot I think its the culprit.

Its a little tight in there I think the first step would be to remove/loosen the belt. I'm sure there is a post about this in the archives if you do a search.

http://www.peachparts.com/shopforum/ml-gl-g-wagen-r-class-unimog-sprinter/103418-serpentine-belt.html?highlight=replace+tensioner

http://www.peachparts.com/shopforum/tech-help/76303-1993-300se-belt-tensioner-adjustment.html?highlight=tensioner

http://www.peachparts.com/shopforum/tech-help/87501-1992-400e-serpentine-belt-tensioner-installation-procedure.html?highlight=adjust+belt+tensioner

Those are the threads I can find but...

Question: Does the belt tensioner automatically adjust itself over the life of the belt or do you have to go in there every x amount of miles to adjust it manually?

The symptoms sound like a bad timing chain tensioner rather than a bad drive belt tensioner.

Wow thanks. These are awesome. Just what I needed. I searched but only under my car model, maybe that is why I didn't turn much. This is what I needed. Thanks.

Yeah never do that. Always search for the item you are talking about and then sort through the results for something close to your model ;)