DESKR

Sent MB C280 for overheating: result: replacement of viscous coupling, thermostat and flush radiator. Got it back, drove a few k's and all hell broke loose, tensioner pulled away from engine into fan, broke belt etc.
Mechanic would have me believe that the bearing in the tensioner went and thus cause of damage. However, I am of the opinion that they did not
fasten the bolt on the unit. Big fight!! Can someone tell me if the bearing failure could cause such a catastrophe

wblynch

Well the bearing could fail and cause that damage but you'd have a visible failure.

If the idler fell off because they didn't properly attach it, that would look much different.

Should be pretty easy to tell the difference. Ask a third party to inspect it.

$tallion

yea that sounds right have a third party investigate

My tentionor was replaced also i had a ugly sound which caused me to replace it the bearings would have been screaming for them to explode and do all that... My theory

Untertürkheim

Your mechanic may not have broken it, but I would consider it negligence if he did not notice the problem before/while fixing.