My E55 AMG has been running progressively worse over a 2 month span. The power has decreased steadily so it now feels like less than 50% of what it should be. I had stopped driving it altogether because of how bad it was running so I took it to a local Mercedes mechanic last week and had a great chat with the salesperson(?) who seemed a nice guy and competent. He wrote down all that I had been experiencing then said he was going to have a meeting with the mechanics the following day to discuss what the issue could be, then run diagnostics to see if the results correspond to what they had discussed so they could then determine the best solution. He explained 2 of the mechanics had 25 years each experience with solely Benz and the 3rd mechanic had 10 years experience. I was confident the car was in the right hands.

The following day the head mechanic phoned and said the car was running great, had impressive performance, drove well and the diagnostics hadn't shown any errors. I wondered if I had missed something or was just being pedantic - surely not - I tell you what, they almost fooled me! I picked the car up and put my foot down a little considering their enthusiasm and within a day or two the car was running so poorly and hot that I couldn't possibly drive it any further. I thought the motor was on the verge of catastrophic failure. Eventually a mechanic mate and myself finally worked out the supercharger was totally shot and appears not to be even working now - decreasing the power a huge amount. And this "reputable" Merc shop reckons it was "impressive" and "running well". It feels like s%&t - I don't know what they normally drive?

Prior to the deterioration of the supercharger I had removed the undersized sc pulley, replacing it with a stock pulley as I installed a 180mm crank pulley instead. I also replaced the bearing in the sc pulley for good measure and flushed the jet oil twice within 3 weeks. In addition to this work I installed a 5 piece billet alum pulley kit from Shardul plus a Belt Wrap Kit. Initially the car pulled insane with what felt like lots of boost but very gradually declined in HP and response. People who only got in the car every week or 2 noticed it more. I have posted in this forum seeking answers but no-one picked it and none of my "knowledgeable" friends or mechanics were able to pick it either. The car has travelled about 7000 km since the work was done.

So my questions:

1. Armed with this limited information has anyone experienced similar and if so were you able to repair the supercharger or did it require replacement? (as I assume it does).

2. Could further damage have been done to the motor driving it in this condition?

3. Does anyone have a supercharger in good condition that they would be prepared to let me have at the right price? I have really had a lot of bad luck with this E55 with it costing me over AU$30,000 over the past 18 months aside from the AU$45,000 buy price. I know this ain't no bleeding hearts forum but aside from that I have just left the town where I was living in dismay and frustration with almost $100,000 owing me that I probably wont see and the vultures stealing most of my valuable belongings before I left. Again I'm not complaining but it would be nice to have a win for a change lol.

 

What boost did you have before and what do you have now?
Are there any misfires?
Mileage on the car?
This is where logging comes in very handy

 

I lived in a mining town so no performance shops or Mercedes specialists. The only logging was using DashDaq on the iPad so couldnt tell you what the boost was except it felt like the car wanted to tear itself apart when launching it pulled so hard. It already ran exceptionally well prior to the last round of mods - very tight and quick.

There are no misfires - the motor itself seems to be running smooth enough although it has developed a throaty note through the exhaust and definitely rougher.

She has clocked up just over 200,000 km (about 130,000 miles).

I'm no mechanic but my thoughts were to take it to someone who knows AMG's and get them to test timing and boost etc also check compression in individual cylinders plus look more closely at the supercharger of course.

 

Intercooler pump?

 

That was my thoughts only last week actually. When my mechanic mate said supercharger though it all sorta fell into place. Although maybe the ic pump preempted the supercharger issue?

Using DashDaq on the iPad temps reported during normal driving have been between 82C - 92C and 39C for the intake. It feels hot under the hood.

 

Could the SC clutch be worn and slipping when engaged?

 

130k the supercharger is fine, since you have a dashdaq you should have known what your boost was initially and what it is now and then prolly analysis can be done.

Could be the clutch, magnet, check your boost now

 

I would check your cooling and intercooler pump first.

Sc failure is rare, unless you had rotor failure from alien material going through it and then the whole motor would be gone. I know your MB dealer is proud of thier tech`s combined 35 years but they may not have had much time with your AMG SC engine. Check the simple things first and you can always do a leakdown test to check cylinder compression. Start with the intercooler pump, as it is a cheap fix.

 

I wouldn't have thought so but others more knowledgeable than me might think different. Keep in mind the power and responsiveness and tightness of the motor have all very gradually deteriorated since the crank pulley and other items were installed. I recall the difference being pointed out to me about 2 weeks after the work was done when someone came for a second ride - it wasnt immediately obvious to me as the difference was gradual and continued to get worse and worse until I could no longer drive it - but that was probably over the space of 2 1/2 - 3 months.

 

Did you get it tuned? Reputable shop? OEM Parts? Did you flush the SC oil or did a shop? Can you confirm they used the proper fluid?

 

The car was originally tuned by Eurocharged. I did not tune it straight away when the smaller sc pulley came out and the larger crank pulley went in. I did notice as the power was gradually decreasing and responsiveness dropping off it also seemed to rev a bit higher and was running hotter. Eventually Jerry sent me a new tune about 3 weeks back - lack of funds stopped me arranging it sooner. The new tune seemed to make it run a little better for a few days but the gradual deterioration continued.

The new 180mm crank pulley is an oem which was engineered by MKB who are a super expensive German performance shop. I picked it up at the right price as the last of their stock. It seems to wobble a little when installed but most people assure me this is within spec. I did post a video in the forum and again everyone said it was fine and I was worrying for nothing.

I did the sc flush myself and actually created a thread in this forum at the time. Everything was done correctly with Mobil Jet Oil ll used:

https://mbworld.org/forums/w211-amg/...fill-tips.html

 

Being in the summer heat, it makes sense that you're experiencing heat soak. Double check your intercooler pump as stated above.
Also, you should be able to detect something awry with the supercharger itself by removing the supercharger belt and spinning it by hand.

 

39* celcius which is 102* Fahrenheit is not heat soak

 

Bummer to hear mate. Hope it all works out for you. Not a good run into the holidays!

 

Hi

Without seeing your car in person I bet you have one of 2 issues.

1) Supercharger clutch mechanism is playing up OR

2) Intercooler coolant pump is faulty or coolant issue, or maybe like my car was last week, the intercooler pump fuse blew and my car ran so slow it wasn't funny...replaced the fuse and now it is a rocket again.

If it were me I would start the car up at 4am when it is hopefully as cold as possible outside, let the engine warm up for about a minute or so and take it for a 5 minute run. Give it some wide open throttle and tell me if the car has got all its power back. If it does get its power back on the first few runs I would say you need to replace your intercooler pump. Does the tune you have turn the intercooler coolant pump on?

Can you go for a drive and post a video up?

Regards,

OZZYAMG

 

His iats aren't high enough to say he's heat soaking unless he's not reading it right

 

Did you check your fuel pump and filter, specifically the connectors on the fuel pump side? If they are burnt/melted the resulting low fuel pressure will cause exactly what you describe, and intermittently at that. I have yet to see one of these superchargers go "bad" unless some foreign object entered it.

 

^^^^^+1

 

+2 come to think of it.

 

What are your AFRs on your pulls, that should tell us about his fueling

 

I spoke with the Mercedes dealership just before I bought my E55, I asked about the pumps and filters and since it has been mentioned, I recall them saying that they are replaced around the 200-250km mark. The lads above sound pretty spot it.

 

The throaty note in your exhaust makes me think burnt exhaust valve. I hope I'm wrong, but you really should do a compression check. Start with #8 as it's most susceptible to fuel pump lean issues.

 

The drop in power is far worse than you are thinking. Considering the ambient temps where I lived normally the difference of a night is profound and on hot days I didn't go WOT until the cool of evening - well at the moment she's so low on horses that you cant even tell the difference. Nor can any difference be detected at 1650 revs when the supercharger should be kicking in - she just runs sluggish at any revs or any temp.

You're right, I've read a lot in this forum and cant recall seeing anyone with issues directly attributed to the supercharger. I will check the fuel pump as I have no idea when if ever it was changed. It looked ok when I last had a look a few months ago though I have smelt petrol on a few occasions but only ever when filled right up and this occurred well before the problem at hand. (yeah that same old fuel issue, that most on this forum have experience with, that mercedes doesn't want to acknowledge).

102 Fahrenheit IAT and 198 Fahrenheit motor is cruising not on pulls...

The way she feels right now I wouldn't risk any pulls...

I'm leaning towards this also. I will obtain a pressure tester as soon as possible and see what the results are.

Thanks Sean, hope you're having fun with your new beast?
__

Thanks everyone for the replies and suggestions. I just answered the last few but appreciate all the great advice.

Also thanks must also go to to one of the all time great people in the E55 scene who helps an immense amount of forum members and contacted me via PM offering help - cheers Shardul.

I will post an update after checking the items above...

 

I think start off with a compression test.

 

For sure - that's the first thing I'll be doing.