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I have a significant noise coming from the engine of my S600 V12 - sounds like a diesel tractor. It had also been leaking A/C gas for a while and I had it topped up a couple of times. Now I can't operate the A/C at all in the car. When I try and enable it through the console, the check mark just gets cleared from the box immediately and it only blows warm air.
I took it to my local indie mechanic and he's sure it is the A/C compressor making the noise. It is coming from a fan or wheel attached to the front, but he said it would likely have to be replaced as a whole unit. The main problem is he thinks the access is really tight and trying to get to it without removing the front of the car and half the engine will be impossible. Has anyone done this job? Is there an easier way to get access and replace the unit or can the wheel/fan be replaced instead of the whole thing. He's worried that there might be other damage caused and the whole job could run to a couple thousand.
when low on gas you hear a noise that sounds like trans fluid sloshing / or rushing around and whining a bit inside the torque converter...
the bearing on the cush-drive of the AC pump also self destructs
in my experience mega gas leaks come from the bacofoil quality used for the condenser on modern cars - a few winters and the gas weeps out of small pin holes
I read elsewhere that the compressor can be removed, passed out to the side and over the top once the radiator and fans are out of the way. This was on the S600, does anyone know if the same applies for the V12 variant, looks too tight.
if you want to go this deep - you should join the BenzNinja club - one of the elements is the idiot guide of what’s possible for every model they make - plus you can use to check everything to sort the mess you'll have trying to get the next compressor to work again
german manu like to trip up non franchised garages - adding unnecessary complexity to stop things working
A/C compressor will come out the top once radiator fan and radiator are pulled. The rest of ‘the stack’ of heat exchangers comes off of the radiator and stays in the car. Good time to clean up all the years of crud that has accumulated between the heat exchangers. You’ll see. Reassembling the stack is ornery to do the first few times you do it.
Has the alternator ever been done? It is another radiator out task. Easy to do now.
Do new bearings and idlers for the SERP belt now too. How is that belt? May as well install a new one.
How old is the water pump? Pull the crank pulley (one more fastener with rad and fan out) and the water pump is easy to do. Coolant is already drained.
Look closely at the radiator while it is out. The seam in the plastic where intake air goes through will turn into a crack. It is already out...
This is a LOT more pleasant to do on a hoist.
I have done all of the above in my 221 S-65. With the benefit of hindsight I’d do it all once rather than over the course of three years.
Thanks JohnLane for the info. I spoke with my mechanic again today and he said he can get just the front part of the compressor (the wheel/pulley) from Mercedes for a lot cheaper than a new compressor and thinks that way the whole thing doesn't need to come out. Apparently there is a pry tool you can buy reasonably cheaply to pry the compressor belt pulley from the compressor housing. We'll see how it goes. Hopefully, it works as it will be a lot cheaper fix than whole thing out option.
nope the thing unscrews.... remove the large cir-clip around the outer diameter of the AC pulley - leave the belt on then "do it up" via the 7mm headed nut on the end of the compressor shaft - that really undoes it and the belt acts as a great way to hold things still
the blue bit is dust seal of the deliberately undersized chocolate bearing Mercedes choose to use - you can buy the silly size bearing - but the phenolic plastic pulley will self destruct trying to remove / refit - Audi for the same type of fitment use a bearing 2 mm wider
it is also NOT a clutch - this "cush-drive" has no means to decouple the drive - which is what a clutch does when engaged
OP if the bearing on the front of the compressor is dead the compressor won’t live much longer. They fail.
Are you saving money doing it twice?
It was more about access and the mechanic's time to do it. We replaced the bits in the attached picture (genuine OEM versions) and a couple of belts and 1KG of aircon gas, but it was still £750 parts and labour. We'll see if the compressor lasts
Like like JohnLane's approach--just do everything while you're in there including a whole new compressor. I bought a Four Seasons compressor for only like $200, currently on my shelf. While my part cannon approach may not be for everyone, I don't understand doing a big labor intensive job and not replacing small $30 bits along the way that are bound to fail, because everything on an 18 year old car is headed for failure. Even if the part is $100 like a new Graf water pump, that is still cheap and will never again be as easy to replace with everything off the front of the engine, for example.
if he only swapped the pulley and re-gassed its way less than 60 mins work and $150 in parts and labour
many seem to be using incorrect terminology - there's been no clutch on pretty much any car AC compressor for 20 years
what you have to absorb noise and vibration is a cush drive. This is a feature that is designed to reduce stress on drivetrain components during use. A common design typically consists of rubber blocks that damp the transfer of force between components and effectively reduces shock loading, cutting noise, vibration, wear and fatigue of the components.
the old world noisy clutches were to (electromagnetically) switch on or off the drive to a fixed rate compressor - for more than twenty years they switched over to a variable rate always on compressor - that uses a swash plate - this is usually linked to the engine management and improves emissions, economy, idle stability, and for low power application winds back the AC compressor under heavy loads (acceleration or hills etc.)
I hear you guys and in an ideal world, I would have done the compressor. Challenges are, I don't have the skills, tools or room at home to work on the car myself or another vehicle to use, if it all goes awry and I need additional parts. My local indie, I think charges a reasonable £70 +VAT per hour, that's a lot cheaper than the main dealer. Also this is a V12 and the engine bay is packed tight with stuff, a lot of it has to come out to get the compressor out. I've seen a guy on YouTube doing it with an S63 AMG and it took him the best part of a week. Middle ground with my Indie was do the compressor pulley kit and other bits and spend around 3.5 hours on it plus test drive and troubleshoot any additional problems. His concern was if he went for the compressor and had to remove all that other stuff, things might also get broke that would then need to be put on order and replaced. He only has one ramp, so couldn't put everything back together and move the car somewhere until the bits turned up. The cost of downtime and not being able to use the ramp while my car was sat on it would be passed to me - not a great alternative. So whilst it would have been beneficial to do all the work that you guys recommended, when faced with these real world challenges, sometimes you have to compromise, which is not always optimal.
I've been going to this indie for years and I have no reason to doubt his honesty or his prices. It actually ended up taking him less time than he estimated, but as with all Mercedes genuine OEM parts, they're expensive and that accounted for around £400 of the total spend.
ah v12 might not have room... its a lot easier on the v8 that one might think
50% more cylinders means a longer engine. As mentioned above.... it all comes out just fine once the radiator fan and radiator are out of the way. But they don’t just up and jump out of there either.
Best wishes OP. You may consider assembling a kit of parts over time. I listed them previously for you. When something happens do it all and you’re good for a long time.
50% more cylinders means a longer engine. As mentioned above.... it all comes out just fine once the radiator fan and radiator are out of the way. But they don’t just up and jump out of there either.
Best wishes OP. You may consider assembling a kit of parts over time. I listed them previously for you. When something happens do it all and you’re good for a long time.
For those in the US, keep a regular eye on Rock Auto closeout parts. I do this regularly. When Rock Auto decides to clear out parts, they mark them down by up to 90%. I've accumulated many parts this way, my own 'kit' ready to go when I do a project. It is a garage sale type thing...takes time and patience to wait for things to go on clearance, but many major parts come up for sale over time.
Hmm... .So, everything appeared to be working. A/C very cold and efficient. I didn't actually try the heater until today and that's freezing cold now too. I don't generally believe in coincidences. Any idea whether mucking around with the A/C compressor and pulley would cause the heating to fail? Any plugs or bits needed to be removed that didn't go back right and might be causing the issue?
heat is coolant going round and routed to a rad (heater matrix) in the dash if you ask for heat
AC is another system full of gas that is squashed into a liquid - and works like spilling petrol on your hand - as the liquid steals heat from your hand and changes state to a gas it gets cold
double check its got coolant - then scratch your head coz the car is playing silly buggers - one guy has been on his for two years......
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