On my 93 W124, 3.2 liter M104 engine, I just had my water pump and thermostat replaced by my MB independent. We also replaced the bearing bracket (1042001328), belt pully (6012001070), and serpentine belt (0119974792). We also flushed and replaced the coolant.

All of the above parts added up to $483.00.

He charged me 5 hours labor at $65.00 / hour, for a total labor charge of $325.00.

The total bill was therefore $849.00, including sales tax on the parts.

So, looking at all the posts, 6.5 hours does seem high, especially for an M103 engine in a W126 body. There's a lot of room to work in with a 6-cylinder in the big S class body.

A low estimate seems to be 4-4.5 hours, to a high of 5.3 hours.

I'd get a second opinion.

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".