Locating a vibration

David Owner/Technician Bradenton, Florida Posted   Latest   Edited  
Unsolved
Drivetrain
2008 Mercedes-Benz E350 4Matic 3.5L (272.972) 5-spd (722.6)
Vibration

Hello all, I'm at a point where i feel i need some input in this particular situation. I have a 2008 mercedes benz E350 4 matic.. Vehicle has approximately 88k miles. The vehicle has a vibration in gear at idle, reverse and drive. You feel the vibration in the steering wheel and in the seat, your feat floor board area and reaching over to feel passenger seat as well you can also hear at times the vibration in the interior if that makes sense. 

So the vehicle which is a regular of mine for starters. Customer contacted me with a concern that he was driving home and a pig ran out from the median in front of his drivers side tire and he ran over it.. He was driving at 35 mph he thinks as he wasn't to far from his development. The car he thought was or as he explained slightly airborne..unfortunately the pig died.. Now he claims that for a day or two before taking the car to the body shop that the car drove fine and had no vibration. Now vehicle was taken to local body shop and also happens to be one i recommend and have known the owner for a number of years.. Basiclly cosmetic damage.. He was supposed to get the vehicle back by certain day and they called him and told him that they were having a hard time getting the drivers side axle off of the vehicle as it was stuck. When he received the vehicle back is when the problem started according to him. They informed him that they weren't 100% sure they got the drivers side axle shaft back onto the intermediate shaft all the way but thought it was on. So customer noticed that when putting the vehicle into drive and then noticed as well when put into reverse that the vehicle felt rough but didn't think to much at the time and thought that he was maybe just due for a tune up his words. He goes back and fourth to another state and his daughter occasionally uses the vehicle and said dad whats going on with your car its rough. 

So he brought vehicle to me and gave me the run down and just assumed it needed a tune up. He stated multple times that the vehicle was fine before and right after he hit the pig, only after he got it back from the body shop did he notice the roughness ( vibration). We drove it around the parking lot along with down the street as i listened to his information so i could start my analysis of the situation.. I informed him that the car has a vibration. Now the car drives straight and seems to brake ok. Vibration is only at idle with vehicle in gear, reverse and drive.. So i inspected the vehicle found some discrepancies regarding parts not put back properly from the bodyshop.. I called and spoke with the bodyshop manager and then the owner and informed him of the items i had found.. Then i asked him what was done to the vehicle ( what was replaced and or repaired). Basically some minor cosmetics but they noticed the drivers side inner axle boot was damaged and they removed drivers side C.V.. Axle and disassembled to replace inner axle boot. I said to the owner i would have replaced the axle assembly based pn the miles on the vehicle ( preference) but later found out mercedes does not sell the axle shaft anymore. 

So i got into the items i found that i wasn't excited about that were installed incorrectly which were the drivers side brake caliper was taken off to remove the drivers side c.v.. Axle and the brake flex hose was twisted not pinched but could have caused a possible issue.. The drivers side lower strut bolt was installed backwards and was pretty close to sway bar. And lastly noticed hammer marks on inner can of c.v.. Axle and that there looked like a gap between plastic dust washer and oil pan where c.v. Axle is attached to intermediate shaft. Was informed to fix the items and let him know of the progress and if it was a concern with adding to the claim or if it wasn't related let him know. So fixed all items..was able to get axle shaft on to intermediate shaft by 2 to 4 milimeters more.. 

Vibration still there. As part of inspection noticed that the engine and transmission mounts were collapsed. Not broken as they also are commonly known for as well.. 4 matics are also sometimes known for broken engine mount arms as they are smaller in there overall size which makes them vulnerable to breaking even on some good size pot holes.. Found no other issues visually.. I replaced engine and transmission mounts with factory mounts. For some reason i have found that i certain instances the aftermarket versions are not up to par and can cause someone to chase this particular problem. Note if this was a rear wheel drive in my experience we would have fixed the problem as typically mounts are the answer and we would have been finished.. Not the case as vibration still there. So i contacted one of my colleagues at the dealer i use to work at to get his feedback as well.. He reminded of an issue we had seen in the past that i forgot that 4matics when using aftermarket shafts caused this actual issue and that they install mercedes benz shafts and that is the fix.. Now there wasn't aftermarket shafts installed but the shaft was taken off the vehicle and a new inner boot was installed along with alot of hammer marks on shaft probably when they were fighting it to get it off and back on.. Again mercedes does not sell this shaft anymore so my colleague says they just install a new boot kit.. What do you do when its wornout?. So my assumption at the time was did they put the inner tulip part of the shaft back in the same location as they took it apart for wear purposes.. Before removing axle shaft loosened all subframe bolts to see if it could be bound up as I've ran into this before, along with exhaust system loosened at manifolds and transmission cross member as have also had this as vibrations in the past as well. Vibration still present. Removed drivers side c.v.. Axle assembly to inspect and possibly see if this would allow for some diagnosis for would this eliminate the vibration which it didn't just allowed front diff to spin.. I found a c.v.. Axle company that specializes in remanufacturing c.v.. Axles along with mercedes benz 4 matic axles with emphasis on this problem along with there so called procedures that make them better than others. replaced both c.v.. Axles in the front.. When i had axles out examined intermediate shaft and found nothing that i thought was needing addressed spun it and didn't look bent nor did it have in and out play.. 

Vibration still there.. So this was long winded my apologies if so just thought i would put it all out there so incase i missed something someone could give me feedback.. Now i do own a pico scope but i do not have the NVH KIT which maybe my next purchase.. Also to add as soon as the vehicle starts to move from standstill vibration goes away and drives smooth down the road just like it should.. I then decided to look at misfires or anything related to engine running concern just to make sure i wasn't going down the wrong path, no issues found.. I'm in florida so we are some what always needing air conditioning and noticed its sometimes worse with AC on and a little worse with electric engine fan when it turns on as well.. Removed serpentine belt and didn't seem to help.. Additional notes at times when driving and coming to a stop light or stop sign vibration is not there while in drive or vibration is less. i can then put it into reverse and its back. When power braking it from 700 rpm to 1200 rpm vibration changes as well.. Meaning sometimes its worse at 800-900 rpms goes away at 1000rpm but will come back at 1200rpm and is worse.. 

Not sure this is good for diagnosis but just putting it out there. So if anyone reads all the way through this and can give any advice would greatly appreciate it.. I feel like this site is awesome as there is lots of great and world of info.. So thanks look forward to hearing from anyone. 

Thanks. 

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Michael Mobile Technician
Clinton, Utah
Michael Default
 

David, From your description it sure sounds like something is transferring the normal vibration of the engine to the body. When reading I instantly thought motor mounts, but you got them handled. I wonder about any other mounts on transmission. Also any solid AC hoses or coolant hoses that could be leaning on the body. Damage to the subframe, sway bar or other suspension that could be making…

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David Owner/Technician
Bradenton, Florida
David Default
 

Thanks for the quick response back did not expect at this hour which is why i like this site.. All mounts where replaced with oem. Subframe bolts had no visual appearance that subframe was shifted along with having loosened to see if it would pop or shift back into place. Pig was intact according to the picture i saw of it and found no evidence of body parts stuck in anything. I too feel like…

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Terry Technician
Gillingham, United Kingdom
Terry Default
 

Hi David My immediate thoughts turn to the transmission and its torque converter. i would be tempted to carry out a transmission flush as its possible the airborne shunt may have upset the operation of the lock up clutch and fingers crossed the transmission flush will put it right again. considering this seems to be a non electrical fault as you have read all codes, a mechanical fault seems to…

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Jim Owner/Technician
Charlotte, North Carolina
Jim Default
 

For what it's worth, I had the exact same car come in about a year ago, with very similar vibration- ended up being timing chains and balance shafts, they stretched enough to upset the balance shafts and create a very unique vibration that felt like a EGR valve was stuck open. Dealer had thrown motor mounts and various other things at it to avail. We actually had to replace the balance shafts…

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David Owner/Technician
Bradenton, Florida
David Default
 

Hello to all.. Thanks again for your responses.. I don't have any codes and when i looked at the actual values i found no evidence through these values that suggest this being a possibility. Now saying that I'm assuming then that this particular car you where involved with also had no faults just symptoms.

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Jim Owner/Technician
Charlotte, North Carolina
Jim Default
 

Correct- no faults, just vibration, and slight engine noise if I remember correctly,

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David Owner/Technician
Bradenton, Florida
David Default
 

Hi mr gordan, do you recall seeing any timing values that where out of spec?. And just for clarification was this happening when vehicle was on gear as only noticeable in reverse or drive. Thanks

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Jim Owner/Technician
Charlotte, North Carolina
Jim Default
 

Definitely more noticeable in gear, D or R, can't quite remember what data we looked at, but upon pulling the valve covers, the problem was obvious. I am just starting to use/ learn about my new in cylinder pressure sensors, not quite up to speed with them yet, but they would probably give conclusive results about the engine timing.

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David Owner/Technician
Bradenton, Florida
David Default
 

Thanks Mr, gorman and to all that gave some needed input. I forgot about pressure transducers.. So i have a pico and will be looking into this concern. Thanks

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Florin Technician
Niagara Falls, Ontario
Florin Default
 

Hi David, I was wondering if you had a chance to have a closer look at the harmonic balancer. I had a few situations on early 2000 E class with vibration at different idle speeds and had replaced harmonic balancers solving the vibration problem. I don't know if on 2008 is the same design but if you look close you might see the rubber within the pulley has shifted. For what it takes it is worth…

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David Owner/Technician
Bradenton, Florida
David Default
 

Hello, thanks 2000 year if memory services right there was recall for that exact problem.. I worked for Mercedes benz at 3 different dealers.. Im am looking at it now as we message and will let you all know what findings are once i do some more investigation form everyones imput.. Thanks.

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