on my 2007 GL450 (114k miles as of July 2023)
maintenance:
engine oil change interval used to be one year/13k, but now 6k miles, mobile 1 0w40
brake fluid reservoir refresh every year
engine air filter every 20k miles,
cabin air filter every 4 years,
new H8 battery every 3 year ($200 ea, costco/sam's club)
windshield wiper blades every 3 year
tire pressure 36 psi, Michelin defender LTX

Repairs I DIY'd
replaced rear air bags two rounds ($150 ea, Arnott),
front airbags (second round, $480 ea, arnott) done by mobile mechanic on driveway ($180 labor)
replaced air suspension compressor and valve control block ($700 kit from FCP)
replaced thermostat, idlers, tensioner and belt (~300 rockauto)
replaced coolant reservoir ($100 MB dealer)
replaced brake pads on all 4 wheels ($120 Arkebono pads, rockauto)
replaced steering fluid reservoir and o ring ($70 FCP)
replaced gasket of oil filter housing and of oil cooler ($30 FCP)
replaced spark plugs ($100 FCP)
replaced pcv covers and oil separators ($120 FCP)
replaced starter motor (bosch starter $180, mobile mechanic labor $140)
transfer case, front & rear differential fluid replacement (all 8 plugs $98, + gear oil & transmission fluid from MB dealer)

to do:
transmission drain & fill
refresh front suspension parts: CAs, ball joints, brake rotors, sway bar links & link bushings (parts: $1400 from RA & FCP)
replace cam position sensors (oil leaking around it, bosch sensor: $30 each x 4)
replace alternator
replace intake manifold (lever broken) - maybe not

before all these, MB dealer performed:
2 front struts $4200
transmission conductor plate $2300
AC compressor $2400
some engine seal $600

 

Don't waste money repairing the intake. It will break again and made zero difference in drivability from what I could tell between broken and fixed.

 

Thanks for the input.
Yes GL450 drives fine and the MB dealer never proposed to fix the intake manifold in annual state inspection.
has been postponing replacement of the intake manifold.

 

I would certainly also not listen to a dealer who says it’s a requisite to get through state inspection. Just disable the functionality in DAS and you’ll never see the light again. It has zero zip nada zilch to do with the emissions cleanliness of this vehicle.

It’s been well-maintained and out of what you have left to do I would focus on the tranny flush and starter motor.

 

Ditto. If you want better part throttle drivability, jam the flaps in closed position. If you want better full throttle performance, jam them in open. I would do the latter.

You also can replace the lever arms.

Check your alternator if you are having to replace the battery more often than every 5-6+ years. Dying starter will accelerate battery consumption too.

The transmission guys I have talked to recommend a simple fluid change instead of a flush, performed every 30-40k miles. You will use more fluid and filters, but there is less chance of shocking the system with fresh oil.

 

thanks for the advice. will focus on the starter motor, alternator, and transmission drain & fill. and also maybe transfer case and/or differential oil change
I change the engine oil every 6k miles using mobile 1 0w-40 Euro formula. also regularly refresh brake fluid in the brake fluid reservoir.

kind of surprised that the radiator and water pump are still working fine after 16 years. but ready to replace them anytime.

 

FYI - and it is information only - MB originally wanted a 15K oil change interval. Mobil 1 is that good. You might consider replacing just the filter instead. Also, folks at BobIsTheOilGuy ran tests on filters and found the Fram Ultra reigns supreme. Mann was not in their test suite. You really can't filter oil well enough; going down to <1 micron would be ideal. Truckers that run million mile motors do super-filtration of their oil.

When the radiator goes, it is because the rubber seals between the side tanks and the aluminum core start to leak. The leakage is very slow, at least at first. I have a water pump sitting on my shelf in anticipation of the original one starting to weep coolant, but at 180k miles have seen nothing. If it ain't broke don't fix it.

If you go to change the transfer case fluid, you might want to change the transfer case chain while you are in there, as that will require at least draining the fluid into a clean container if not changing outright. Eventually, depending on driving style, the chain will stretch to the point it jumps teeth on the gears, and then those will need to be replaced also.

 

I've replaced all the rotating engine accessories on mine except the water pump. Whoever built them for MB did a good job!

Eric

 

Not replacing the intake is a viable approach and I certainly don't fault anyone for wanting to save the money, but I would highly recommend not replacing the broken lever with a metal one. The old lever broke because the flaps were too hard to turn. The next time it breaks it could be inside the intake which means plastic pieces possibly dropping down into the intake tract. For me it was worth it because the cost wasn't obscene and I like when everything works the way it's supposed to. The intake on my '11 E350 is original and still moves as freely as ever. As long as you keep up with maintenance it *should* last a good long time. I think I remember hearing the flaps got gummy because the PCV system wasn't maintained, but who knows.

 

That's a good point.

Why do the flaps stick? I could see the flaps getting loaded up with blowby - but the question is, what is the difference between a functioning and non functioning PCV system? There is an odd-shaped PCV separator on the driver's side front valve cover; this is ducted to the vaccum side of the intake manifold and enters at the top, just inside of the throttle flap. The other separator we all know and love is on the back side of the passenger side valve cover and is ducted to the air filter side of the throttle flap.

So if one of these gets plugged, what changes about the gunk that is let into the intake manifold? The only thing I can see is that the fumes become more concentrated in the duct - but per mile, it is the same fumes.

It can't be fuel varnish; the injectors are right above the valves, downstream of the flaps, right?

Maybe the flaps just become sticky internally as their bearing surfaces wear out and the flap shifts and sticks against the inside of the manifold.

Also, if the mating of the lever to the flaps' axial rod is weak plastic, it could be that weak spot is far weaker than anything internal, and the OMG PLASTIC BREAKING INTO THE ENGINE meme is just fear **** to get you to buy a new manifold.

In my opinion the flaps are hopelessly gimmicky, an example of Germans' fetish for making everything perfect at the cost of reliability. I would jam them in the open position and leave it at that.

 

You forgot to say “Einsaugsklappen nicht eingebaut” three times over your shoulder and then do the chicken dance.

If they move freeishly by hand, it isn’t the gunk resistance that breaks the pivot arm. Brittle plastics under vibration will do that at 1E10^6 cycles (repeating of course) all the time, regardless of how clean or gunked the inside of the manifold is. Also not worries about thin plastic shards breaking off either. They’ll melt before doing much harm.

 

Yah. Heat, too, degrades the plastic. That's a lot of cycles, too.

The problem with plastic chunks getting sucked in is not so much what they do inside the combustion chamber, although carbon chunks can be problematic, but them getting stuck in an intake valve and propping it open, maybe even interferencing with the top of the piston. Conceivably could get stuck in an exhaust valve, which would be worse.

Why put such a dainty assembly in the intake anyway. It's just asking for trouble.

Friend of mine lost a chunk of intake valve guide. It went in the cylinder and he could hear it bouncing inside for a little while until it found its way out the exhaust.

 

was the engine damaged at all? Hopefully not.
thanks for sharing.

 

Nah, valve guides are typically bronze. Harmless.

 

texas008, I bought our '07 GL450 new and it is a 1/2007 build car. My repair list is very similar to yours, although we are at 88K miles. I have done most of the repairs myself.

Last year when the weather turned 0F, the thermostat failed OPEN, so I need to replace the thermostat for the first time before it gets cold again.

I also need to replace all the fluids. The transmission will be done for the 3rd time, but this time by me versus the dealer. Any good DIY for the 7-speed in the GL450? I do know that I need to purchase a transmission pump as there is no top side fill port.

I dropped off the car this morning at the dealership for the brake booster campaign and asked the dealer what a transmission fluid/fill costs; answer: $895!

 

I did the brake booster check at MB dealer in July 2022. No problem found with the brake system.
I'm sure there are youtube videos on replacing transmission fluid on GL/ML, will check the videos before doing the service.
I've already bought the MB transmission fluid at the FCP:

Mercedes Automatic Transmission Fluid MER-001989680315
Price
$22.69
QTY
8

 

I did a filter and fill at the dealer for 395 with the coupon in 2021…

 

Another option is to get a reputable mobile mechanic to replace the transmission fluid on your driveway. labor cost could be ~$120.

 

I recommend using the transmission service upgrade kit from FCP. The difference is it uses the higher quality filter and deeper pan from the next generation of the 722.9 with the blue fluid (but still uses the appropriate red fluid). I used it on my W212 not too long ago. I ordered it by accident but after discovering what it was, I was really happy I ended up with it. It's been driving great!

https://www.fcpeuro.com/products/mer...n-001989680310

 

@atraudes This is very interesting! Do you happen to know how much additional fluid the deeper sump takes? Also, for a 2007 GL450 with the 7spd, what is the correct fluid? The red or the blue? TIA.

 

Mercedes Automatic Transmission Fluid - Genuine Mercedes 001989680315

https://www.fcpeuro.com/products/mercedes-auto-trans-fluid-001989680313

 

I found in the Q&A they said it adds up to half a liter depending on application. The amount of fluid in the kit's supposed to be adequate, FWIW.

The blue fluid started getting used around 2012 for most Mercedes and the fluid in my '10 GL was red, so yours should be red as well. FCP's support is quite good. I'd drop them a line if you have any doubts about fitment.

 

Thank you for the information. Today I drained and replaced the transmission fluid/filter; very easy job frankly. While I was at it I did the T-case, front and rear diff. I am at 89.900mi and this was the 3rd. time on all these fluids. First time was at 36K miles (Dec 2013) and then at 61K miles (Jan 2018). Everything was clear, the T-case was the most aged.