Several possibilities; faulty fan motor fuse, faulty fan relay, faulty fan switch, faulty fan motor, faulty fan motor wiring or connection.

Several possibilities; faulty fan motor fuse, faulty fan relay, faulty fan switch, faulty fan motor, faulty fan motor wiring or connection..

Yes it could, BUT, when you raise the engine rpm, the tapping should not follow the engine sped exactly. Or, when you raise theengine rpm, the tapping usually diminishes or goes away when the cat is the cause.

Need more information - is this a question in regard to how-to-replace the drive belt? Is there a question with regard to the relative cost of this repair?
Try the rephrase the issue you are having in the form of a question - and post a reply - for further assistance

Need more information - is this a question in regard to how-to-replace the drive belt? Is there a question with regard to the relative cost of this repair?
Try the rephrase the issue you are having in the form of a question - and post a reply - for further assistance.

First, try the owners or maintenance manual with the vehicle. Next, try the on-line manual sources, such as; www.manualspace.com for the maintenance schedule.
Mercedes uses a Flexible Service System that takes into consideration your cars operating characteristics for service recommendations. They have gotten away from the 30, 60, 90,000 mile intervals. For the most part you'll just do lubrication services every 13,000 miles. For example, if you're coming up on a 39,000 mile service where they also recommend new fluid and filter in the transmission and new transfer case fluid. I recommend doing an oil and filter change in between each lubrication service. At 2 year/26,000 mile intervals they recommend a new cabin air filter. Engine air filter is recommended every 52,000 miles, fuel filter at 65,000 miles and spark plugs at 78,000 miles. Brake fluid should be changed every 2 years.

As for the relative costs involved for these services, check with the local repair shops in your area - or you can try the "Find-A-Shop' and 'Estimate Cost' features on the AutoMD website.

First, try the owners or maintenance manual with the vehicle. Next, try the on-line manual sources, such as; www.manualspace.com for the maintenance schedule.
Mercedes uses a Flexible Service System that takes into consideration your cars operating characteristics for service recommendations. They have gotten away from the 30, 60, 90,000 mile intervals. For the most part you'll just do lubrication services every 13,000 miles. For example, if you're coming up on a 39,000 mile service where they also recommend new fluid and filter in the transmission and new transfer case fluid. I recommend doing an oil and filter change in between each lubrication service. At 2 year/26,000 mile intervals they recommend a new cabin air filter. Engine air filter is recommended every 52,000 miles, fuel filter at 65,000 miles and spark plugs at 78,000 miles. Brake fluid should be changed every 2 years.

As for the relative costs involved for these services, check with the local repair shops in your area - or you can try the "Find-A-Shop' and 'Estimate Cost' features on the AutoMD website.

These are usuallly dealership prices. One cannot say if these are reasonable or expensive - without having any other prices for the same work - from other dealerships or repair shops in your area or region. Try to do some comparison shopping for the service work - before you buy so you'll understand all the costs involved.

Read a shop or repair manual for your vehicle to learn to perform the most basic preventive maintenance work yourself to save these costs.

Probably a ripoff. What can possible be needed on a 2012 MB car? Such a high end car certainly doesn't require repairs already? I assume there is little mileage on the vehicle, (you didn't say) but if you are saying that you paid $350, then that might pay for an oil change (about $120 to $140 in parts - full synthetic motor oil about 9 quarts) plus labor of ? $50 maybe (even though a $50 labor charge is unheard of in the aftermarket - excessive) so that give you $190 and now lets throw in a tire rotation for ? (another $35 maybe at most) that is total $225.

As far as the $650 bill, I can only say what could his 2012 vehicle have needed serviced already besides an oil change and a tire rotation that would not still be under warranty. Insane.

just had oil change 8 qts. synthetic oil on my MB gl 450 $107.00

The oil life reset procedure is in your owners manual.