Hello,

So I am on a bit of a bad luck streak with my 07 Mercedes s550 with 182k miles. As most of you know I have done recent cosmetic upgrades to it but about 3 weeks ago my mechanic noticed an oil leak coming from the oil filter housing. He replaced the engine oil cooler gasket as well the oil filter housing gasket. These leaks caused the serpentine belt to slowly weaken and eventually snap ruining the idler pulley as pieces of the belt got caught in the idler pulley as well as the crankshaft seal becoming compromised. With all that said I believed that there would be no issues for alittle bit but that’s not what happened lol unfortunately. Last Saturday I was driving home from work and noticed that the check engine light was on and the car seemed to be in limp mode as the car was very sluggish. While on the highway I heard a loud bang which caused me to pull over to the shoulder of the highway. When I opened up the hood I noticed that the brand new serpentine belt was once again shredded. When I look much closer in the engine bay I noticed that there was another pulley that had broken. Well this time it was not a pulley but the clutch to the ac compressor. The ac compressor is somewhat below the oil filter housing and of course the engine oil cooler. So the past oil leak definitely caused the plastic compressor clutch to become weak and caused it to break over time. Sadly my mechanic didn’t mention replacing it at the time of the last pulley/serpentine belt replacement. This is what lead me to post. I have recently purchased an ac compressor kit but wanted to share this story with everyone so they may address the above oil leaks so that they don’t go down the same path as me. As you can see oil leaks can lead to break downs on rubber and plastic parts in a short period of time.

 

OP.... an oil leak didn’t kill your A/C compressor.... 182,000 miles of enjoyment killed it. Any time I do a SERP belt I take a hard look at all the idlers and listen to bearings for the alternator, water pump, A/C ect. It is all suspect. With 182K on the car expect to be dealing with this kind of stuff.

 

Probably true but all the major parts you listed have been replaced with the exception of the ac compressor. The leaks 100% had to do with the previous repair as the belt was replaced at 175k miles. Regardless I fixed it and the car is back on the road.

 

You didn't by chance recently upgrade your NAV to include the "bird's eye" view? If you did, there is a known issue of the update resetting the magnetic clutch to "ON". If this is the case, you need to use DAS and change the compressor electronic magnetic clutch setting to "NO" or "OFF". The 2007 does not have a magnetic clutch!!

I know it sounds crazy. I have a 2007 S600.

 

Thank you for the information but I believe the demise of my ac compressor was age and the oil leak.

 

The compressor exploded or the clutch/pulley? I don't think an oil leak can make a compressor explode but it could in theory cause damage to the pulley I suppose.

I think what really kills these compressors is that oil slowly leaks out and eventually the thing just grenades.

 

the w221 has a variable rate compressor and there is No AC Clutch - there is a cush drive inside the plastic drive pulley - and it runs a bearing that is far too small gets noisy and could fail - as the phenolic pulley won't survive pressing out the hard to come by bearing size - you need to go to specialist AC places

https://en.euro-klima.pl/?___store=EN&___from_store=PL

bearing waste of time https://www.ebay.co.uk/p/28003690707?iid=282025774710

 

hello,

so it was the clutch pulley that was weakened by the constant oil leaking on it. I actually ended up buying a rebuilt ac compressor kit with all the o rings and new dryer along with the expansion valves. The car has been towed to my
mechanic and will be ready by Friday. The orginal compressor did for sure last 182k miles so really can’t complain.



QUOTE=kevm14;8661225]The compressor exploded or the clutch/pulley? I don't think an oil leak can make a compressor explode but it could in theory cause damage to the pulley I suppose.

I think what really kills these compressors is that oil slowly leaks out and eventually the thing just grenades.[/QUOTE]

 

its not a clutch and the rubber element of the "cush drive" I guess could wear, but the bearing normally fails first

the cush drive is to take up shock loading, vibration and generally give life a helping hand - its almost identical to the cush drive on the rear sprocket of a motorcycle - no one ever called that a clutch - the issue is on the variable AC compressor it looks quite similar to the electromagnet clutch that clunks in and out on pre 2003 AC systems - but a swash plate (see pic on the link I had above) allows the compressor pistons to travel at varying rates to save fuel and on small engined car's can be programmed to wind back the AC load when accelerating hard or going up hill - these better compressors started to be common on many brands circa 2005

 

Well I think his story is that oil somehow caused the phenolic pulley to come apart. Which I guess is plausible. I don't know how oil reacts with that material but it swells in brake fluid, I know that...

 

NOTE clutchless -

 

I thought of one good thing for the clutchless design (aside from fewer parts to fail): the input shaft always turns so that particular seal system shouldn't suffer from issues pertaining to lack of rotation

 

well you can certainly leave it on as its so much more efficient you'd a complete fool to ever tun it off - and I guess your point is valid