Hi Guys,

2nd time MB owner (first was an E420 Sport). Just picked up a 2010 GLK 350 4Matic w/ 160k from my neighbor. I was not aware the M272 could be such a pain but I think I'm up for the challenge.

Error codes below:

P0175: System too rich (bank 2) current
P0172: System too rich (bank 1) pending
P0172: System too rich (bank 1) historical fault

Powertrain codes:

P0746: Pressure control solenoid "A" performance or stuck off
P0750: Shift solenoid "A"
P0292: A camshaft position actuator control circuit low bank bank 2b
P2096: Post catalyst fuel trim system too lean bank 1

There is some significant chain rattle or valvetrain noise coming from the passenger side (is this bank 2?). I'm really hoping this is a function of the cam position sensor for the VVT not functioning correctly. IF its the chain, I'm going to dump the car. The oil isn't due for a change and is 5/40 syn but I'll be changing it tomorrow in the hopes that clean oil clears it up at least a little.

I've read some historical posts and believe the codes are the result of:

Bad intake manifold variable length runner actuators (should I buy a rebuilt manifold? the Uro replacement parts?)
Bad/dirty MAP or MAF sensor
Possibly bad cat(s)
Faulty harness to CPS sensor from oil penetration

I'm totally unsure of the trans related codes. I'll be doing a trans fluid/filter change (seems to shift fine now). Any thoughts here?

I'll do plugs and possibly coils while I have the manifold off.

Additionally, the car HVAC isn't working. I've taken out the blower motor and tested the positive/negative wire and am not seeming to get any amperage though I am getting a fractional voltage reading. I don't want to start throwing money at this car and replacing things that might not be bad as its A. a winter/cold weather daily. B. I've done this before with my other cars (XFR, 911 Turbo, etc) and it gets expensive, fast. Any thoughts on what else could be wrong here as well?

Is there an affordable MB specific diagnostic tool that would better fitting for diagnosing some of these error codes? I have VCDS for my VW R32 (what this GLK is supposed to replace) and its been great.

MANY THANKS in advance!

 

Why duplicate posts ??

 

Fixed.

 

Why did you buy it, was it super cheap, I think new oil will make the noise worse, it’s thinner. My 13 has the high pressure fuel pump on passenger side near firewall. Mine makes noise. I don’t know if your model has this system. Mine has made noise forever. Sounds like you bought yourself a problem

 

What was the problem? I think the m272 is the more reliable of the bunch to be here honest. So easy to work with

 

It sounds like you have done your due diligence, and are well on the way to getting that pretty "new" car sorted.

First, on any automatic transmission, a fluid and filter change is going to be the best thing you could possibly do (particularly if the transmission hasn't been serviced before!). That's likely to fix the error code, as a shift solenoid is just an electromagnet, which can attract "gunk" that's in the fluid. Changing to new, fresh, clean fluid can make a big difference.

I suspect the new (cleaned?) intake will take care of your other issues. I'm not up to speed on that one (happily) as my 15X,000 mile 2011 GLK doesn't have any symptoms of a dirty intake. I've looked at the issue, and at this point am not sure if I'd try to just remove and clean the old one, or replace it (and whether or not I'd replace the plastic flap linkages with metal). Either way, it's not an insurmountable issue.

In the end, when you buy a "new" car with over 150,000 miles, you have to expect some deferred maintenance issues. Most owners just don't have the attention to detail that many of us DIY wrench-twisters do.

FWIW, I picked my 2011 (one owner, highly maintained, nearly spotless) GLK up for chump change because it had munched the front driveshaft, taking out the infamous front output shaft (internal) U-joint. That, and bad (noisy) motor mounts resulted in a fair amount of work, but I'm still miles ahead of where I'd be if I'd bought the same car without issues on the open market.

 

I'm shocked your variable-length runner actuators haven't failed with that many miles as they're poorly designed and manufactured from the factory out of plastic. Proper oil changes (and not some bs 10k interval) keeps the flaps from getting carbon build up though. I found a replacement on eBay for $100, where they regularly got for 160.

Trans fluid/filter/gasket will all be addressed. Agreed on your points. I took the front bumper off today (for repaint) and in turn, found ~100 walnuts in my intake tubes. I changed the oil w/ Mobile 1 5/40 and I no longer (at least on the first start-up) have the valvetrain/chain rattle that was highly evident before (contrary to the post from above oil is often thinner as it degrades as the lubricating molecules break down, this is oil 101).

I will be replacing the front 4 control arms and sway bar links, the strut assembly/mounts, as well as brakes. I'm trying to keep this mechanical refresh under $1000 with literally the cheapest parts I can find. This is a "beater" for me so I'm absolutely not doing things like replacing the sway bar for fresh bushings (I'll happily splice eBay bushings on). I'll probably also do the cheapest coil packs ($65) which I consider the highest risk of all the cheap parts I will be using. I will, however, use quality plugs.

Yes, this car was cheap ($3500). Goal is to be able to put hot chicks in this car during winter and not have them question what they're riding in.

Perhaps I'm in the wrong group for M272 mechanical.

Picture of the walnuts for humor at my expense.

 

I can save you some money on your beater... don't bother replacing coil packs that are currently working. They'll most likely still be working 50 years from now... not much to go wrong with them, and I'd MUCH (!) rather have six 12 year old Mercedes coil packs than six brand new no-name Chinese coil packs. The exploits of those who've caused a host of new issues with cheap coil packs are everywhere.

I'd be careful about replacing the intake with TOO cheap an alternative. I've read some scary things about some of them (seems that the casting is weak and can break). Not really a job you want to repeat, so I'd look for an intake from a quality source - or perhaps just pull your old one and clean it up (being careful to use products that won't embrittle the plastic bits).