The camshaft adjuster solenoid (which is related to the variable valve timing system) may fail or timing chain/balance shaft components may wear, resulting in illumination of the Check Engine Light and various drivability issues. Mercedes-Benz has released a service bulletin outlining specific repair instructions depending on fault codes stored.Google+
Car Problem Reports
Mercedes-Benz ML350 Camshaft Adjuster Solenoid Failure
Mercedes-Benz ML350 Problem
Average Mileage: 65,901 mi (9,948 mi - 125,211 mi)
Visitor, 2006 Mercedes-Benz ML350, 63,000 mi
Check Engine Light stays on. First I was told the camshaft adjuster solenoids needed to be replaced - I had all 4 replaced. The Check Engine Light came back on the next time I used the vehicle. Now I'm being told the balance shaft gears are wearing and the balance shaft needs to be replaced - estimate is $5,500. Mercedes is aware of the issues but has not issued a recall. From things I've read on the internet, a national class action complaint is being prepared - let's hope the courts can force Mercedes to "do the right thing".
I was informed by Mercedes service that my virtually new vehicle has a camshaft problem such that the camshaft has to be replaced for no less than $6,600. This sounds like an endemic problem in these models necessitating a recall by Mercedes. Please let me know if anyone else is experiencing this problem with their vehicle.
Best Regards, Michelle T. Harrington
Visitor, 2006 Mercedes-Benz ML350, 67,000 mi
Check engine light at 66K miles, transmission shifting hesitation in 1st and 2nd gears, failed electronic test for emissions at DMV with "Camshaft is out of alignment with crankshaft." Mercedes confirmed and gave an estimate of $5000. I asked them if they could cover it under the 60K mile warranty and they came back and said they'd cover 2/3rds of it. I then contacted them with information from this site and mentioned a class action suit from New Jersey, and this time they came back and said they would cover it under warranty. The camshaft had only 2 teeth remaining on the sprocket at the time of repair. As they were fixing this issue they also encountered broken seals and worn parts in the automatic transmission (also estimated as $5000 to repair.) Since the camshaft was covered, they decided to cover the transmission repairs as well. Appreciate the fact that they covered the repairs (the parts were called 'faulty' by the service tech), but it required much negotiation on my part, with them first trying to get me to pay for the whole thing, but eventually they gave in when they realized I knew they were trying to get me to pay for repairs to faulty parts.
Visitor, 2006 Mercedes-Benz ML350, 125,211 mi
Check Engine light on for 3 months, Have been told by 2 different MB shops that problem is Counter Shaft Gear Wear (Known Problem) and the Other Shop says it needs an intake manifold. Both Repairs in the Thousands of dollars.
Visitor, 2007 Mercedes-Benz ML350, 78,000 mi
Check engine light comes on and when check indicates cam sensor problem. I was told that Mercedes knows about this problem and has a silent recall on this. When I checked with them one dealer indicated it knew nothing about it and another did. The one that did wanted receipts showing regular oil changes which I did most of the time by myself and could not produce. Now an estimate to repair on my own is close to $5000.
Visitor, 2006 Mercedes-Benz ML350
Check engine light came on at 70356miles. Was told thermostat camshaft adjuster magnet and oring need to be replaced. Engine was running colder than it needed... maybe the camshaft was stuck open. Cost $550. I am tired of this ML 350 and will be looking to unload it very soon.
Visitor, 2008 Mercedes-Benz ML350, 51,000 mi
Check engine light came one and I was told a sensor in the camshaft had gone bad. If this is an issue, why aren't they covering these issues?
Visitor, 2007 Mercedes-Benz ML350, 94,000 mi
CEL while traveling out of state with young son. Went to the local MB dealership, always serviced at our home state MB dealership and had copy of all service records in car. I was told that the repair would be $5800! Zero offer of MB assisting with cost of this known problem (unknown to consumer at time of purchase) This was our first and last MB. Thankfully I was visiting my home state and was able to trade it in (at a wholesale price) on a new(non MB) vehicle. We will NEVER buy another MB and 3 of my family members just sold or traded in their MB for another brand. We are just thankful we were not hurt. Cant imagine that MB could know about problems with the balance wheel, crankshaft and not feel the need to inform their customers. Never once while having our vehicle serviced at a MB dealership was this mentioned.
The Check Engine light comes on randomly and I'm tired of having it checked. The ML350 transmission is a piece of crap and I've neer been so disappointed in a vehicle in all my life (BMW, Nissan, Isuzu, GMC, Mitsubishi, Mercedes). Mercedes should be ashamed of themselves - this car should have been recalled years ago.
I refuse to put one more penny into this poorly designed transmission. If anyone has this problem (and I'm sure there will be several) threaten to write a letter to the regional manager and that should get you somewhere. Once I'd did that my $2000+ bill disappeared magically. With that said, they know this is a systematic problem and worse yet, only Mercedes is "authorized" to fix the problem.
Visitor, 2006 Mercedes-Benz ML350, 84,000 mi
P0016 an P0017 error codes.