m119 400 accessory belt tensioner replacement - PeachParts Mercedes-Benz Forum

mus · #1 05-12-2010, 11:27 PM

How hard is it to change the accessory belt tensioner on a 1992 400e with the m119 engine. Mine is shot...again! happens every 2 years down here in texas. My mechanic charges about $350 for the job and I was wondering if its sort of thing a backyard mechanic could do. thanks

JohnM. · #2 05-13-2010, 12:33 AM

Might want to find a different mechanic or at the very least buy the tensioner assembly from a reputable manufacturer. Should be good for 100K+, regardless of where you live.

macdrone · #3 05-13-2010, 01:53 AM

The heat will do it tho its the tension once you take it of the auto tnsioner it falls apart. Yes its a easy DIY job. Plastic cover off front , use socket to take tension off the belt, remove belt, remove 3 bolts, install new tensioner with locktite, install belt and good to go.

mus · #4 05-13-2010, 11:23 AM

thanks all. the mechanic has kept care of the car since it was off warranty and the shop has a great rep around town. does not sound like its that easy to screw up in any case. I have heard others say this is a common issue, while others say they should last. The belt and tensioner on the V-8 m119 is different than on the other motors, even more serpentines to make.

there are different versions by different manufacturers available in the parts shop. I have the old style tensioner I think. Is there one brand that is recommended over the others?

mus · #5 05-17-2010, 03:05 PM

okay, got parts. have instructions off the shop repair CD.

Any tips? is there anything I need to do, like hold the fan still, etc. or is it really just unscrewing the one bolt indicated in the shop manual?

any tips on getting the new belt in?

samiam44 · #6 05-17-2010, 08:41 PM

Is it easy to update to the later style belt tensioner??

Might save some bucks in 2 years.

Michael

mus · #7 05-17-2010, 10:09 PM

good idea, however there is a thread on that in another mercedes site. apparently its not very easy; you need to get a new timing belt cover, etc. with the right bolt hole locations, or something.