Considering a GL350 Project
 

New to the forum and really to MB. Been an owner of LR, Jag, Volvo and BMW before. I've now spent a few days scouring this forum to gather as much insight on this/these models before taking the plunge. I must say, I've been part of several forums for each of my other cars and this site is one of the better ones. A lot of really great replies and knowledge shared among the community.

I understand these diesel models have their problems but without spending a few more days compiling a list of all the issues, was hoping a few of the "experts" could chime in with a bullet summary of issue's I may face if I pull the trigger on the project. (i.e. common issues that plague these models) I do plan to delete the DPF/EGR/SCR/DEF as I live in a state that does not require emission testing on diesel vehicles which hopefully will address some of the more problematic issues associated with the GL350.

Common/Recurring Issues?
Items of note to look at closely when checking out a perspective vehicle (specific to this model)?
Anything I should be aware of that I might not have already read about on this forum?

Not going to be a daily driver, but if I like the outcome it may become one... I am very mechanically inclined and plan to do most/all work myself (is there anything specific that is a "dealer only" repair)? Is there any reason I should run fast from considering this project? Not looking for an overall money bit, but a solid platform I can start with.

Thx in advance for any feedback/comments...

Also, most the vehicles in the 2010-12 range have just north of 100k miles on them. What are the common issues/maintenance items associated with this mileage range? Traditional thinking would say that is still relatively young for a diesel, but I'll await the MB expert opinions.

Thx again

Looks like the oil cooler seals and timing chain will be the biggest concerns, considering I would be removing all of the exhaust emission related nonsense anyhow.

Thx for the reply

Adblue everything!!!
NOX sensors $700 a piece
Strange electronic issues that come and go.
Air conditioning works perfectly unless it is hot outside.
Oil cooler seals leaking. $2000
Intake runner failure. $2200
Door lock motor burned out. $750
Mass air problem that I cant find an answer for. Engine light has been on for 3 years because of it.
Battery drains through various electrical systems when off and in garage.

I've never owned a diesel, but I've owned my GL450 since new in 2007. My GL worked awesome for about the first 7 yrs without a problem besides normal maintenance items (tires, brakes, etc). I came to the forums trying to work on other things outside of the warranty, but it's clear the American diesel versions of the GL are much more susceptible to other maintenance issues than the gas versions. If you're set on getting a diesel, I don't want to sway you. But having lurked and/or been a member on this board since 2007, I can tell you for certain the American diesel GLs have many more problems compared to the gas versions of the GL. European models of the diesel GL seem to have far fewer problems. These SUVs in any version are awesome. We love our GL. But I just wanted to give you a perspective from a guy who's been an owner and forum searcher for the past 12 yrs.

Best,
James

Deleting the pollution controls theoretically removes most of your problem areas with the engine, but I've not seen any data on whether that's really true or not. It would allow you to run much better (i.e. thicker) oil which would give you better summer protection than the 5W 30 you essentially have to run due to DPF. That then leaves you with all the 'normal' GL problems like Airmatic, poor quality exterior trim, and electronic gremlins. My 2012 has only 69k miles on it, so all the emissions stuff has been covered by MB so far (as well as numerous items that were covered under the original warranty.) The only non-warranty repair of consequence was replacement of the timing chain at 55k miles (I did it myself.)

Before the government required the emissions Mercedes specified 5/40w for winter, and 15/40w for summer/hot climates. These oils protected the engine well and many of the older diesels have the mileage to prove it.

I would be running 15W 50 or maybe even 20W 50 in the summer months. Whatever manufacturer you prefer.

I'm currently running Pentonsin Superperformance 3 since my pollution controls are in place. I'm trying to find a thicker oil for summer use since 5W 30 just doesn't cut it. I'm also looking for ways to get additional cooling air to the turbo, which shouldn't be too difficult since I have tons of cooling hose/ducting laying around from the race car.

Thx all, I appreciate the replies and input.
Let me know your thoughts/opinions on this possible vehicle...

2011 GL350 3.0L - 123K mi. for $12k (originally was asking $16k, negotiated to 12k)
Owner reports many of the common issues have been addressed:

• New rear air suspension
• Oil cooler seals replaced
• Oil filter housing replaced
• DEF heater replaced (plan on removing all exhaust components anyway)
• No present timing chain slap (even though should probably go on the short term list)

Thx again!

I have a 2012 with 125K miles on it. I recently performed the oil cooler seals and timing chain. The oil cooler was leaking and the timing chain was giving the good old "slap" for a few seconds at startup.

The job took me 2 full days (about 20 hours to do both jobs), but was not too complex. You will want to get a good set of diesel fuel line crowsfoot wrenches. I purchased a set containing 14mm,17mm,19mm for $39.99 with free shipping on ebay. Trying to use anything else will be very frustrating and will cause a very good possibility of damaging your injectors. Also, do yourself a favor and get the Mercedes WIS/ASRA&EPC digital manual. I purchased the software on the same site for $15 and it details the entire process and torque specs. I would not do this project without it.

I also recently started getting the Adblue/DPF issues and have mostly resolved the problem as it seems to have been a failed NOX sensor. I purchased a new one online for $200 and it tool about an hour to replace (though had to cut the wires off the old one to get an impact driver over the sensor for removal). All errors are now cleared except a nagging issue that the regen keeps aborting. I am thinking I need to perform an adaptation or online coding to "reset" the system, but am new to Xentry and this level of diagnosis.

Speaking of Xentry, if you plan to own and maintain a Mercedes you will likely want to invest in a Star tool to use Xentry. I purchased a new VXDIAG multiplexer for under $400 and for less than $50 also got Xentry Developer mode running on an old laptop. The $500 invested will pay itself back quickly if you ever need it.

These are great cars and well engineered. Yes, oil cooler seals in the bowels of the engine really suck to change, but once done you are good for 100-120K miles. The AdBlue/DPF issues can be frustrating, but with a little patience you can sort them out or delete the system. I get average 30 MPG with a stock system which is incredible for a huge heavy SUV. If you are not at all handy expect the maintenance on these will be expensive. If you are like me and not afraid to turn a wrench or take some time to learn the vehicle you will be fine. Despite the repair costs and headaches, I am still in love with my GL350 and plan to run it as long as it will go.

Wanna sell some of that emissions stuff if you get one?

Going to be working on the emissions delete next week. Parts will be available if interested...

All of my emissions stuff is already deleted too. And I mean ALL. The only thing I wouldn’t be able to give up is the DPF. It’s clogged to the core lol...

The pollution controls are a Federal requirement. Resale value of your vehicle is now zero.

I dunno. I'd buy it. Big plus if I knew I wouldn't have the expense to repair or delete myself later. Also, you're off topic. I for one would prefer that you save your rants for a thread discussing the ethics of a DPF delete.