Looking at a 550 or 450. What are the major issues that are common with these vehicles? Best and worst years?
I have a GLK350, nice vehicle. Little small. No major issues so far, and its at 80k , 2015 2wd model.
I can do most maintenance like brakes, oil changes etc, with exception of major, ie transmission, engines etc. Just getting too old.

 

A simple search on this forum would yield many results. But since I'm here and NOT one of "those" guys that would leave you hanging, I'll give you a breakdown of my issues on my 2010 GL550.

1) Airmatic suspension. It fails on almost every GL. Arnott is the best replacement as the strut assembly comes with a lifetime warranty and they have excellent costumer service.

However.

If you want your best bang for your buck AND want to have a factory new ride feeling, go to www.FCPEURO.com. Whatever you purchase, excluding fluids, are 100% lifetime warranty. Meaning if you order an Mercedes branded air filter, 15k miles later it needs replacement, fcpeuro will replace that filter for free.

2) Sway Bar end links. You'll eventually hear a random squeaking or knocking sound in the front suspension. Someone posts once a week about this. Indy shops will make recommendations on what it could be etc. Its your sway bar end links. Use FCPEURO. They have an easy way of figuring out what is OE and what is OEM.

3) If random things start acting off or odd. Its most of the time battery replacement. The GL will start doing odd things like, turning your GL off and the left rear taillight will stay on. The COMMAND system will randomly shut off. Battery replacement and everything once again works correctly.

4) This should go without saying, routine maintenance. Its a must. That goes with any vehicle. Don't cut corner's and by cheap parts either. Obviously you bought a Mercedes because they're beautiful vehicles and most of the time you get what you pay for. Same with parts. I personally by OE or OEM parts. Same with fluids. I personally stick with factory used fluids that were used at the time the vehicle was built, unless MB themselves say not to use it anymore.

5) Tires. I've personally had to purchase new tires every 10-15k miles for my GL550. Tires are a little pricey for the 550. At a size of 295-40-21, not many manufacturers make them. I've always used Continental all season WS6 cross contacts. With purchase from Tirerack and installation (balanced and mounted), looking at roughly $1300.

6) If you're not good with doing your own wrenching or work, this could costly for you. I personally do my own. I've saved thousands I'm sure. Not ALL things will be DIY though. Some will need a STAR tool to make adjustments needed after replacing a certain part.

In closing, MBWORLD has saved me thousands of dollars by the help of members post entries. There's a wealth of knowledge on here and a lot of good forum posters. Search and search.

 

I have read of the air suspension. Seems like something I can do. I have done suspension swaps, just getting a little old, and takes more time.
STAR tool?
My wifes GLK battery gave her issues.. Amazing, as most cars arent very sensitive to loss of juice. But, a tight battery ground and positive can be a wonderful fix.
Tires are about the same I pay for my Corvette, every 5 years.
Thnx for FCPERUO, I may need to use that for the GLK350. And this forum has helped allot..

 

Star tool - aka MB Star / DAS
if you want one look up user shardul

or you can get some kind of harbor freight code reader that is compatible with mb - won’t be able to change much wrt settings and such but it’ll tell you what’s going on.

bottom line is you need some way to read and talk to the car.

 

I have a code reader with torqu pro

 

I'm on a 2010 GL550 myself, about 146k miles so far (30k by me). The struts had been replaced at 90k if my memory of the service record was correct, but other than warranty maintenance, that was the only major undertakings prior to purchase. I had to replace the thermostat after purchase - it was working but not regulating properly and throwing a code. 20k later, a new alternator, and battery, and I just put a new set of tires on it - I had winter wheels to get through the snow. I've been using the Lexani's from Amazon, since I get about the same wear as Contis, have no balance or noise issues, and they're relatively cheap. Mounted and balanced for under $200 per wheel. I figure as much as fast as they wear (AWD + weight), I'd safe a few bucks each time. IY on it hasn't been difficult, though the Alternator was a little more time consuming than others I've done. Other than that though, it still handles great, goes fine, no creeks or rattles, and everything still works on it, even at this mileage. I've had few cars with that number that haven't had major issues either come up already, or developing. That said, the 450, you'd save more on tires being smaller sizes, you'd have more winter tires to choose from in the smaller sizes also if that's needed, and maybe safe a mpg or two with the smaller engine, by giving up the more aggressive styling. I have no doubt I'll get another 100k out of mine, with as solid as it is still today.

 

2007 GL450 250k+ miles. Best car I've ever owned.

 

I guess I have been over thinking reliability on vehicles. When you buy a Benz, you expect certain things. German engineering, reliability.

 

Just don't get the diesel. They are a nightmare.

 

I have two GL450s - one with 200k and one with 125k on them

Not counting oils and filters, tires or brakes -

both have required new suspension airbags all four corners at around 100k

one required a new compressor because the leaky rear airbags had been left in place for too long

that also destroyed both rear shocks as it was riding too low for too long

Both have required a trans service every 40k (this is one thing best done at the dealer with a coupon)

both have required new batteries every 100k

one required sway bar end links at 175k

both required power steering reservoir o-rings

this is a pretty complicated car but perfectly diy’able

preventive maintenance of the above is key

just make sure you do not have or create water leaks into the cabin or trunk area, which will destroy the car’s electric modules in short order

 

The prior posters have all given great recommendations and suggestions. As far as year, if you're looking at a x164, stick with a 2011 or 2012. These were the last years before the model change and had all the bugs worked out. The engines are solid for those years. I own a 2012 GL550 with 98k, no mechanical issues, just routine macitence and the occasional air suspension issues, which Arnott air suspension will take care of as mentioned above. Make sure you have service records and check to see if all the schedule maintenance was performed. Best of luck!

 

With the 450, stay 2009 or newer since the early 2007 and some of the early 2008 models had balance shaft issues. I think there was the same issue on the 550. No need to buy a 2012; in my opinion, you should not buy a 2012 and instead go for the X166 since there were so many upgrades to the GL. I have both and the 166 seems light years ahead of the 164.