I recently bought a 2014 GL550 and the threads on the M278 and M157 engines are depressing and concerning. Mine runs well at 89k but I'm nervous. My question is (not trying to jinx anyone) who are the members who've had solid reliability from their GLs?

 

2013 GL450 with 130K miles - no problems with the engine (knock on wood)

The only problems I've had are soft close doors locks going out one by one

edit: I did have the check valves/tensioners recall done early on

 

not me. 3 months and $5400 in. Having serious second thoughts

 

Do you know the fix for the soft close door locks?

 

When I had them done the car was still under warranty and the dealer's fix was to replace the soft close mechanism.

 

2013 GL450 bought new in Dec 2012 just turned 145k. Only engine issues were a leaky valve cover gasket (minor) around 60k, one bad coil around 95k, re-sealed the oil pan at 140k. Other notable spend was basically the entire air suspension between 130 and 140k. I replaced one rear air spring around 110k, and when the other started leaking around 130k, ended up replacing the front air struts (Arnot Reman), both rear shocks (Billstein), and the other rear air spring. I then replaced the air compressor and distribution block as it was running constantly and getting noisy from overuse. The ride improved significantly. I recently replaced the driver seat cushion with an OEM cover ($300) and added the Road Top carplay unit. The car looks and drives like new.

I've read much about bore scoring and tranny failure around 150k. I'll let you now in another year...

 

Have not heard of such transmission failures...

 

2013 GL450, bought with around 85k, now with around 110k, had various coolant lines leak, oil in the harness (caught early and fixed by replacing all four sensors and repeated cleaning), steering column master switch go out ($500 part). Otherwise lots of maintenance (brakes, tires, batteries, fluids). Upgrades have only been winter wheels/tires and second row headrest thing. A great vehicle when it's running properly. I've done almost everything myself, it would be too expensive to own if I was paying a shop. Recently developed a random once-a-week hard start where it cranks for 5 seconds before firing, no codes. Had to replace a $500 rear tailight that was busted out during a hit-and-run parking lot incident. I will say that it's really easy to work on, I bought one of those iCarsoft diagnostic tools ($150) that's worked great.
Overall I can tell it's a quality vehicle. I bought it when it was 7 years old, and it was in better shape that the other vehicles that I've owned when they were 7 years old. I know the maintenance and repairs are going to be very expensive going forward, but it's the nicest 7-passenger vehicle with a 7500 towing capacity that I can afford and fit in my garage.

 

Also have the cranking issue for over a year now. No codes... New batteries. Dealer is clueless. I just ignore it now.

 

I'm sorry but I'm not really answering the question the OP asked. Sharing a tale of caution.

When I posted a day or two ago I was pretty busy and didn't have time to delve into this whole scenario. Here it is though now that I have a few minutes.

I have a 2015 GL550 which I acquired with 61,250 miles and which now has 67,001 miles. V8 is awesome when it's running correctly, but in 3 months of ownership have had a few major (in my view) problems. I was warned by a family member that works for MB dealer that I should stay away from the twin turbo 8 and I didn't listen. The allure of the AMG body kit, the extra growl and HP sucked me in. The options including softclose doors, heated cupholders, cooled seats, and B&O sound didn't hurt either. In the three months of ownership I was stranded twice. Once by a battery that wouldn't take a charge and required a flatbed (while my wife and 2 kids were in the car and it was 0 degrees out) and once when the car started to misfire violently on the highway en route to an appointment over an hour from home. The battery was $550. The misfire on the highway was $3850 to fix 3 fouled fuel injectors. I also spent $800 replacing spark plugs and the number 3 coil and another few hundred on an oil change and suspension inspection (for peace of mind). The car was also burning oil. At first 1 quart every 1,000 miles. Today, 1 quart every 300 miles. Big puff of blue smoke out of the tail pipe on cold start.

After these things happened, I spoke with my cousin who first said "I told you so" and then said to never again buy a GL/GLS without a warranty. He is a service supervisor and sees the following issues as commonplace and costly: repeated engine coil failure, repeated spark plug failure, repeated fuel injector failure, significant oil burn. Also, blue/white smoke on cold start due to leaky valve seals, piston ring failure, or bore score, and failure of the air ride suspension. He has seen most issues start around 50-80k and continue for the life of the vehicle which is typically diminished unless it was CPO and major engine components were replaced under warranty. The naturally aspirated V8 had better long term reliability but is still susceptible to bore scoring over time and some cam shaft issues. He scared me enough to take a huge bath on what I paid in October vs. what the market will bear now. I traded for a 2018 GLS450 with CPO and extended warranty. I'm told the V6 is more reliable overall as it is the workhorse of a large part of the lineup. There are still air suspension issues but that is what the warranty is for. All in all, I'm out about $19,000 in lost value if you include all the service I did. Seriously painful...but could have been much worse if the car continues to have problems.

When I picked up the car after the fuel injector repair the 'check oil at next refueling' came on yet again and I had topped it off 300 miles earlier. So I guess my tale is just one of caution. If you start having major issues, I have it on good authority from someone who works for one of the largest MB dealer repair centers in New England that you should move on before it bites you harder next time. I chose to do that. I hope no one else here has the issues I did.

I take delivery on Friday.

 

Solid post. Sorry to hear about your experience but it is entirely consistent with many similar posts on this site. I'll summarize by saying MB is junk.

Congratulations on the new GLS. Please post a photo when it arrives. The 3.0L TT V6 is far more reliable than most MB engines.

 

It does seem that these start having major issues around the 50-80ish area (From what others have posted here). It is also shocking to hear about a 2015 having similar issues as the very early production MYs with this engine.

Not sure if it consistent with the W/X166, as I do not recall hearing or reading such similar issues on the W221 and W222 M278 S550s.

 

Can we get production numbers for the platform with the M278, then can we also estimate how many were serviced ahead of the ridiculous schedule, how many don’t use top tier fuel and how many get driven hard, how many get driven off hard after a cold start, how many live in cold climates and do short drives? Once you compile all this data we can draw a correlation to the amount of failures outside of the design. I bet you can’t pin point but the bad always get attention vs the ones that run in tip top shape, you won’t see post from those people they tend to have busy lives. Point is Porche, Jaguar Land Rovers have had their share of blocks and pistons issues when we go away from steel liners but doesn’t mean they are all junk.

I’m not going to lie, it crosses my mind my car has any of the so called common problems. But I’m at 117,000, bough it at 100,000 coming up on the year. No weird engine noises, no puff of smokes, no check engine lights. I do my own work and only done a couple of oil changes at around 5k full synthetic. The truck Mostly works as it should. No air ride leaks yet. I do have a front strut that likes to clunk over big bumps, never challenged the dealer as it’s intermittent. System holds air and will wait till it gets worse or it leaks. Worn tires has been the other bigger issue but I should have been more diligent when buying. Dealer took care of the drivers motor mount after complaining it was a safety item. I have an erratic harsh 1-2 2-1 shift that happens in 1-100 chances when conditions are met, Like changing direction quickly. It used to do it more often but a filter and oil change helped tremendously, it’s likely a dirty valve body solenoid. I read up on fixes and seems to be common thing, then there is the adaptive programming service procedure. It doesn’t do it enough to bother me. It shifts flawlessly the other 99 times so not gonna worry.

I’m not taking a bath on this car, I took a bath on an Escalade I traded against and need a few more years of service before even considering. I will not live in fear either, If it fails big time I’ll just deal with it. The older they get the more salvage parts will be available and will just change it with used if it happens. But so far so good, I will also ignore the bad soft close on the passenger side haha. The truck is fast, handsome (550) smooth and fits my family, designio leather leather and I’m mostly happy.

A better question is, how many ppl have reached 200k and what have you done to get there.

 

So, it seems that MOST M278 (after 2789xx 30 128000) could have the valve guide issues? I took a vin from a 2017 S550 W222, for example, and it would still fall in this. meaning the majority of M278s are risk, even later MYs? But again this seems most prevalent in the X166...

I understand the timing chain issues were early on, along with the camshaft sensors (which MB updated the PN on these to correct the issue).

 

How do I provide the production number? Is it the VIN? I’m not familiar with this. Happy to share though.

 

Any of the vin decoders will tell you

 

Have you considered an extended warranty? A 3 year / 50k mile Drive policy from Freedom Warranty, repairs accepted by all Mercedes Benz dealers in North America, covered for $110 in labor an hour, only $100 deductible, $4,840. 0% financing is available, contact me with any questions or to see an example contract at (602) 909-9216 or tgibson@highline-autos.com

 

Trent- I haven't seen too many aftermarket warranty companies that are universally loved. Googling "Freedom Warranty" seems to be the same case. As this is going to be just a fair weather vehicle and not a daily driver, AND considering how much I overpaid for the vehicle as it is in the crazy market, I think I'm going to roll the dice on this one.

 

I personally have more happy customers than the few poor reviews online, with 100% claims acceptance on all of my policies, I'm not some dealership promising the moon just to get a vehicle sold, just helping other forum members with something I know and trust on my personal vehicles. I was just offering you information for something to consider, not many can say their GL is still under warranty after 11 years and almost 140k miles.

 

Well I would definitely consider a warranty if I was putting serious miles on this truck, there's a lot to go wrong and none of it is cheap. Thanks for your insight!

 

FYI.
Order number:0 5 715 62389
Delivery date:08 12 2014
Market: NA,North America
Production order:N
Engine no.: 278928 30 243918

To the extent this provides any value.

 

My GL is from around the same timeframe as you. I do think the M157 and M278 engines are decent, but there's just SO much more going on compared to the older engines. I believe that it's harder to make a "bulletproof" twin turbo direct injected VVT engine. I have M119 and M113 Mercedes V8s and they are considered bulletproof but they are so simple. Naturally aspirated, no bells and whistles. It's still disappointing to hear about the bad luck some people have had though because Mercedes is generally the most reliable of the european luxury cars compared to BMW, Land Rover etc. It's not even so much the issue that things go wrong, it's that the repairs are so expensive. Even if I was a shade tree mechanic and was going to throw a replacement junkyard engine into a 2014 Mercedes GL, a USED M278 is $8000!! So you can't even shrug and say "Well, no warranty, that sucks but I can grab a low mileage replacement motor from LKQ for $3000 and slap it together." The other thing that drives me nuts is why Mercedes has so many wiring harness issues. From 93 to 95, they had the biodegradable engine harnesses that were falling apart, which they refused to recall. Then they got that resolved and almost immediately here's the transmission modules getting fluid in them due to capillary action. And here we are with the X166 chassis, it's STILL a thing! I've never heard of any other automaker having problems with oil going through wiring harnesses. I'm saying all this as a diehard Mercedes nut. And you search for answers but it's all speculation online in the forums.

 

Mercedes has almost never stood behind their numerous and costly defects. Mercedes is JOKE now, I won't buy another. They just aren't worth it anymore....

 

I think almost all of the automakers have serious reliability issues because we are in this inbetween phase of gas engines and electric. Gas ICE engines have been pushed to their absolute limit of efficiency and complexity, so there's problems there. Let's get an EQS - well, all electric is complicated and relatively new and has a lot of issues to resolve. So I get when people are frustrated, or we long for the days of an old W140 where you can change your plugs and it doesn't have crazy plastic thermostats mounted under an intercooler and intake and take 15 hours to change etc. It'll be interesting to see where this all goes. But yep I share your frustration when automakers are gaslighting consumers and refusing to acknowledge problems or make good on them. All of them love to trot out that "1 quart of oil consumption per 1000 miles is normal!" etc etc

 

So true. My wife had a 2015 Q7 and we traded it with 91k on the ticker. When we bought it never burned oil. After 65k it started burning a quart every 3k and that kept getting worse. I urged her to get out prior to having to do head gasket or other similar repair which she did. She now has an ‘18 GLE 43 and so far it runs great and has only needed brakes and spark plugs at 53k. Got it with 25k.

I previously had a 7 series and while I had it, zero issues. However while under factory warranty the previous owner had the “Customer Care Package” done on the M62TU2 engine and it was literally a complete rebuild that took 3 weeks. They replaced all high pressure oil lines with braided hoses, all gaskets, plugs and injectors. So I essentially got a brand new engine that had 50k on it. I never had a problem before selling it. I felt like that rebuild was above and beyond and a sign of BMW finally acknowledging that stuffing turbos in the V was a bad idea and they bore some repspnsibility for the issues Inherent in their engine design. That rebuild was my sole reason for buying that car and i wouldn’t buy one that didn’t have it done or wasn’t under factory warranty. I sold it 1 month before my CPO warranty expired.

My experience with Mercedes is they probably would have bandaided that situation as long as possible until the car was out of warranty but maybe I’m wrong. They seem less capable of admission of responsibility.

My long way of saying I agree with you guys.