2008 Mercedes-Benz R350 Repair and Maintenance

A guide to problems, costs, maintenance and repair for your 2008 Mercedes-Benz R350

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2008 Mercedes-Benz R350 Problems

Rough Shifting of Automatic Transmission

Vehicles equipped with a 7-speed automatic transmission may develop a rough shifting condition, most commonly going up from first to second gear and going down from third to second or second to first gear. Our technicians tell us this is due to an internal component failure. Mercedes has released updated parts; the transmission will need to be removed and disassembled to complete the necessary repairs.

Oil Seepage on Back of the Cylinder Heads

The Mercedes Benz R350 may have engine oil seeping or leaking from the back of the cylinder heads. This is commonly misdiagnosed as leaking valve covers.

On the back of the cylinder heads there are three, in total, plastic expansion plugs that plug access ports to the camshafts. These plugs are well known for seeping oil, and leaking if left unattended. The oil will run down the back of the engine and eventually make it to the ground. 

Replacement of these three plastic plugs is extremely simple, and should be done as regular maintenance. The recommended interval for replacement is every 60,000 miles.

Check Engine Light and Engine Noise

The engine in the R350 is known by Mercedes Benz to have issues due to a poorly manufactured gear on the balance shaft (also known as the counter-rotating assembly). Since the balance shaft gear is driven by the timing chain, which keeps the engine rotating synchronously, when it fails, the timing of the engine will change causing:

-Illumination of the Check Engine Light

-Rough Running Conditions

-Stalling

-Loud Rattle or Slapping Noise

-OBD Trouble Code P1200 and P1208

Correction for this issue is replacement of the balance shaft, or balance shaft gear. Replacement of the timing chain and tensioner should be done as well. The Mercedes Benz dealer may cover some or all of the repair cost on select vehicles as a result of a class action settlement.

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2008 Mercedes-Benz R350 Questions

A loud reving/fan sound came on and off an hour after being driven (1 answer)

It would come on suddenly like a siren, then taper down, up and down a few times. This was about an hour after I had driven it, keys out, and all locked up!?

where is the main computer located on the vehicle? (1 answer)

It is the main computer for the engine.

Where can I get a fuel filler door (1 answer)

I need to replace the fuel filler door. Color of vehicle is black

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2008 Mercedes-Benz R350 Recalls

Mercedes–Benz Recalls 2008 Vehicles for Defect in Power Steering Oil Pressure Driving Pin

Mercedes–Benz is recalling certain 2008 GL-Class, M-Class, and R-Class vehicles for a possible defect in the driving pin used to control power steering oil pressure. If the pin breaks during normal vehicle turning, the steering assist will no longer operate, causing difficulty operating the steering wheel. Dealers will replace the steering gear in affected vehicles.

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2008 Mercedes-Benz R350 Reviews

Rated
based on 3 customer reviews
I purchased this car about 1 month ago at a very good price. I read consumer postings regarding the relative issues and decided for the price it was worth the headache. Due to the left rear airbag leaking, I have replaced the rear air ride system with standard springs and shocks from Strutmasters. It was the best investment I made. Rides and drives well. Really everything else is regular mainte...
This is supposed to be a Mercedes. MB Corp need to have the courage to fix the problems that are common in all R350 such as manifold exhaust system, and air suspension issues.
Hello Every one, I just need to give some advise to the ...nothappyMBowner.... I think you do not need transmission most of the times the transmission control module unit goes bad on new Mercedes so you need to replace that part and will cost you $120.00 part on Mercedes Dealer and 2 hours of labor. Remember Guys Mercedes isnot a racing car for fast takeoff or drive crazy. My 2008 E63 Mercedes...

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