expl0rer

Edit: added vehicle info.
2010 GL550, 154000 km

I've started hearing intermittent squaking from the engine when the car is cold started and weather is cold. Sounds to be the accessory belt or a pulley.it goes away after a short while. I can't troubleshoot to pin the culprit because It’s warmer now and have not heard the squeak recently.

So I'm looking to replace the belt and pulleys. I see a few variations out there. One with all MB parts, another is Contitech. My question is, what did you use when you replaced yours, if you have done this?

P.S. the search did not render anything for the X164 on this topic.

I realize that the new belt with proper tension will likely expose or accelerate the wear of other parts/pulleys in the belt loop. I'm tempted to replace the water pump as well, while doing the belt job, but haven't decided yet. Another item to likely go with the new belt will be the steering pump.

eric_in_sd

All depending on the mileage (scuse me kilometerage, u canuck) I would change lots of things while in there. When I changed my belt and pulleys, I had just read that the thermostat ought to be changed beginning at 60k (100 megameters). I bought a thermostat but didn't change it. Wouldn't you know, there goes my tstat a few thousand miles later.

I really would not bother with MB parts on this. Every vehicle on the road uses serpentine belts nowadays; this is hardly a proprietary technology.

I re-seated my power steering pump, sealing the o-ring with Permatex Black (which I also used on the cam housing plugs).

So , it would be the belt, tensioner, two pulleys, and depending on mileage, thermostat, radiator hoses, alternator, water pump ... really don't know what to say about the power steering pump and the AC compressor.

Edit: Whoops you posted the kilometerage. I would maybe change the thermostat. Radiator hoses is a 300 kkm part. Probably the belt simply didn't like your cold winters. You might even get away with only changing the belt, or if it's not cracking inside, just take it off and spray with belt cleaner / stickifying stuff. While it's off, test the pulleys and tensioner to verify the bearings aren't making any grumbling or gritty noises.

Thermostat likes to stick open in early failure mode. That only means the system doesn't warm up. So you typically have warning on that.

expl0rer

Thanks for the details! I got lazy and didn't add the mileage. I've only heard the squeak a handful of times and in the latter part of the winter. The car did spend it's life in the mild NW before I started it's punishment in the NE. The belt looks good, no cracks. I'll try the belt cleaner and test the pulleys. Probably stock up with a Contitech kit and thermostat, just in case.

Yup497

I have a 2010 GL550 with 130xxx miles.

I purchased, Mercedes Drive Belt Kit - INA 272273BELTKT1 from FCP Euro due to lifetime warranty. Price tag was $164.56.

The only thing that was genuine Mercedes was the Serpentine Belt. I kick myself for not purchasing the other parts in the kit with genuine Mercedes parts.

When I start the GL, I too still get the minor squeaking or ticking until the engine warms up. I had the Mercedes dealership perform the work. I've taken it back several times and they're u able to find anything.

I'm wondering if it's a faulty pulley OR the pulley bolts weren't tighten to spec.

I also get the whinning noise at low acceleration (similar to a supercharger whine).

The kit came with the following-

• Drive Belt Idler Pulley

• Drive Belt Idler Pulley

• Belt Tensioner

• Serpentine Belt

expl0rer

One way to pin down the problem pulleys is to spray some water on them when the motor is running. It should temporarily silence them if they are the source of the squeak.

eric_in_sd

Take the belt off the tensioner and try spinning the various slave pulleys. It's possible one of them has developed sufficient drag to make the belt slip. This would imply you are very close to that item seizing up completely and destroying the belt.

It is unlikely any of the dummy pulleys or the tensioner are bad, or mis-installed, but that would be easy to check when the belt is off the tensioner.

A 1/2" ratchet with a 17mm socket and a cheater bar makes it easy to pull the tensioner away, and a wire tie (or a friend) can be used to hold the tension in place while you route the belt.