My MB dealership said I have to change the following parts:
1. Serpentine belt 011-997-97-92
2. Belt tensioner 112-200-06-70

My car is a 2004 CLK320 with 160k miles. To save on the labor charges, what else in the "vicinity" should I change?

I never changed the engine mounts and transmission mounts. I checked and I did not see any excessive vibration on the engine.

 

I'd also replace the idler pulley. The belt, tension and idler pulleys are an easy DIY on that engine.

 

Is idler pulley the same as tensioner pulley?

In the quote, it also mentions this tensioner 000-202-09-19. When I asked the tech, he said "just in case". I would just go ahead to replace it as well.

After I changed these parts, would I feel any difference in the ride or performance of the car?

 

Look at this diagram (the one on the bottom, assuming you have A/C):

http://benzbits.com/M112/BeltRouting.pdf

The tensioner pulley is #7, the idler or "guide pulley" is #4.

 

I myself did not know about this "worn" serpertine belt. This was discovered during a visual check by a MB tech, along with the bad right front wheel bearing. Based to the advise of this forum, I have since replaced both front wheel bearings.

With the age and mileage of my w209, it is probably wise to change these parts.

What are the symptons of a worn seprentine belt, idler pulley and belt tensioner? I myself did not feel or hear any irregularity, maybe I am used to the car.

 

If you have 160K miles on the original belt, it's time to get a new one! As for the pulleys, they are common failures. You don't have to replace them, but when they fail, they usually shred the belt (making a huge mess on the other pulleys) and leave you stranded.

 

My appointment is Jan-19 with the dealership. The plan now is to replace the belt and the 2 pulleys.

I do have to find a knowledgeable indie locally. Upon recommendation of a friend, I went to his indie 2 weeks ago to replace my front wheel bearings. The guy installed the seal (ring) the wrong way and I had 3 malfunctions; ABS, BASED and ESP. I did my search in this forum and told the indie to correct it. I did save money but it was a lot of stress.

 

Just went to the dealership to replace the serpentine belt. In the same time, they also replaced the idler pulley, belt tension pulley, crankshaft pulley, seal ring.

Cost was $1,144 CAN, including parts, labor, tax and my usual 15% discount.

 

Nice overhaul there . Sounds a bit pricey though.

Any noticeable change in engine performance, noise, idling vibrations?

 

I did not notice much, only a short ride from the dealership . Also, the car was fully warm up when I picked it up. I will update later.

My car is well maintained and drives very well. This was just a preventive maintenance because of the high mileage (160k miles).

What should I be looking for after these changes?

As for the price, it was certainly pricey but I do not know of a knowledgeable indie locally. I do have a guy for regular maintenance like oil change, ATF change, brakes, etc. Not sure if I will go to him for engine or other internal works.

 

If it were just the idler and tensioner pulley and a belt, that price would be highway robbery, but factoring in the crank pulley and seal, that's not too bad. Dealer price on parts is around US$700, and ASRA lists the time at 2.5 hours, so I would expect this to be around US$1,000.

 

To itemize, these are the prices:
1. Belt $75
2. Tightener pulley. $52
3. Tensioner. $314
4. Absorber (craftshaft pulley). $462
5. Seal ring. $15

These are Canadian prices. Good that they gave me the 15% discount. I checked the prices from an US dealership, prices were almost the same.

Labor was 2 hours.

 

Where I come from that is a reasonable price.

 

After changing these parts, am I supposed to feel any improvements to my car?

 

No not really. Engine can sometimes be a little quieter due to less noise from worn idlers & tensioners.

 

OK. Thanks. I will try to notice tomorrow.

 

The good news is that you can now drive without worries of breaking down due to a seized pulley or broken belt.

 

+1^

 

I drove this morning and the car felt great. However, my car drove well before the belt change anyway. BTW. They also did an oil change as well.

I went into the Dyno mode when I started the car this morning. While driving, I could see the voltage fluctuated between 14.3-14.4 V. After I stopped for coffee, the voltage statyed on 14.2 V.

The oil level concerns me. When the car started, it showed 8.6L. Then it dropped to 6.0-6.5L while driving. Is 8.6L too high? The previous oil change was done by an indie, the oil level used to be 7.8 L (at startup).

 

That sounds about right. My oil changes usually take 9 quarts, and that's right at 8.6l. BTW, checking the level while the engine is running should be less as the oil is running through the head and other channels within the engine. Full level is when the engine is off and cold.

 

I saw the 8.6L fugure this morning when the engine was cold, right after I started the engine. The garage temperature was around -5C at the time.

So, it seems that I was running a bit low for the past few months. It was 7.8L (measured cold) before this oil change.

This is a bit confusing. I read that the oil capacity of my car was 8L so 7.8L seemed to be right. I will watch for malfunction in the next few days.

 

Oil capacity is 8 liters, or just over 8.5 quarts. I think I end up buying 9 quarts, then fill 8.5 quarts, check, and maybe I have to add a little between changes.

 

I was stuck in traffic today and I was literally going at 10 KMH for 1.5 hours. Because of the change of serpentine belt and the various pulleys, I enabled the dyno mode when I started the car this morning.

During the slow traffic, I observed the voltage and oil level. The oil level fluctuated between 7.0 to 7.5L and the voltage stayed around 13.8V. When the traffic got better, the voltage went back to 14.2-14.3V.

Hope this is all in specs.