2009 ML350 with DTC 1200 & 1208
 

Okay, so the fact that my ML350 4MATIC is throwing these codes confuses me since the engine is WAY over the serial number (starts with 31 instead of 30), but CEL came on with P0016. Got an iCarsoft MBII and found DTC Codes 1200 and 1208 which is typically linked to balance shaft failure. Car is just under 100k. Gets regular service and 5W-30 Mobil 1 per MB specs annually (plus whatever else it says to do). Bought it in 2012, so have had service done annually since then. Before I got the MBII I replaced the camshaft position sensor and camshaft solenoid for the passenger-side intake (the one that's higher) hoping that would take care of it, but now seeing 1200 and 1208 and knowing the engine is definitely outside the range, I'm wondering if even the new balance shaft sprocket wore out? Wondering if it's a stretched timing chain, which was stated in the TSB to be rare, but possible. I know what the balancer replacement runs, not sure of the timing chain replacement cost. Anyone have any thoughts on what this could be? Haven't been able to really find anything online about engines outside the serial range throwing these codes.

VIN: 4JGBB86E99A477680

https://cimg3.ibsrv.net/gimg/www.mbw...c008a64176.jpg
Mr. Bob, this is a common problem with 164.156 engines and it is not an easy job.

This is a 164.186 vehicle with a 272.967 with a serial number of 31 078469, so I'm not sure if the above still applies. I know that the serial is above the range for the camshaft balance adjuster (which requires removing the engine), but the documents you uploaded don't seem to indicate that problem. I was hoping against hope it wasn't the balance shaft adjuster since it's a multiple thousands of dollars for repair, but it seems like even if it isn't that then it is the issues you pointed to which also is not even close to an easy fix. Maybe it's time for a new(er) vehicle... We just got it inspected, so we're good for another year. While I recognize your formal opinion is that it should be repaired quickly, how long do I have?

The procedure is for all 272 & 3 engines.

Major,

If I'm reading your post correctly, you're saying it's not the balance shaft, but instead the camshaft adjusters? What do you estimate the cost would be on that job? The codes don't come right back on after they are cleared, and my indy suggested replacing the 4 camshaft solenoids, which they did, and they drove it around and the lights didn't come back on but then when they were driving the car back to drop it off to me the CEL came back on. I checked the DTCs and of course they both 1200 and 1208 were stored. Thanks!

Bob, I provided you with the code number descriptions for the right cylinder bank and the procedures for doing so. You and your mechanic decided to repair something else.

Now you want to know the cost of this repair. How am I supposed to know? Your mechanic is doing the job, so he has to determine the cost of the parts and how many hours it would take. Why am I supposed to do this work?

Easy Major, I just figured since you knew a lot about the procedure you already had that information in a ballpark sort of way. I know we decided to repair something else and that's on me. I'd just not heard of this procedure and could only find information on the balance shaft replacement, but since you said it's a common problem but not easy to do you might have an idea of what it takes to do it. Apologies if I wrongly assumed you already had the information to respond to my inquiry.

https://cimg3.ibsrv.net/gimg/www.mbw...927feed7e0.jpg


This repair is not easy and very expensive. The adjuster wheel for the right side is approx. $600. These adjusters were replaced with new numbers because of manufacturer problems. It would be in your interest to replace both sides at the same time instead of doing the procedure again in the near future.

Open one of the PDFs I supplied and you will see RED numbers and letters on the right side. Each one is a procedure within that PDF. Then when you go to that procedure they have RED num. and letters, and so on.

You must decide if you trust your mechanic or decide if you should have M/B do the job.$$$$$$$

Major,
Thanks for the info. In talking with my mechanic, we're thinking it might be best not to put any more funds into the car. Also, I did see the red numbers and letters but couldn't do anything to the file to get to those procedures. He offered $8k for the vehicle which is $1k less than they go for at auction (without the 1200/1208 codes), so weighing my options. We have three vehicles, so if the above isn't something that requires pulling the engine it could be something for me to work on in my spare time. But even then I'll have spent all the money on those parts and all my time and I'll still have a vehicle that's 9 years old with almost 100k miles on it.

$8k must be really close to wholesale bluebook. I'd get a second opinion, and if it agrees with the 1st one take the $8k and put into the kitty for the other cars. But if it doesn't, well, then you have another decision to make. :)

If you were going to do the repair or have your mech. do it, then I would have to print out each one of them. So please don't make me do this if you aren'e going to do the repair.

What is the nature of the failure? Seems like a serious engine problem if it is common and on engines without too many miles. Is there any way to reduce the risk of occurrence? What does MB say regarding this issue?

An update: In thinking it's the timing chain, I'm in the midst of replacing that (stupid timing chain guide rail pins...) but took some pictures with my scope of the balance shaft. I think it looks fine (based on what I've seen of worn ones, but maybe mine is only worn a little bit), but wanted to get opinions from others in the forum. Thoughts?
https://cimg1.ibsrv.net/gimg/www.mbw...067d8fc033.jpg
https://cimg3.ibsrv.net/gimg/www.mbw...5b8b5beaab.jpg
https://cimg5.ibsrv.net/gimg/www.mbw...c1afcbdd2e.jpg