speedybenz

I have had this problem that I just can't get a handle on right now. Since I broke a motor mount in two pieces on the driver side of the car and then replaced the mounts and also the right side engine support wing that holds the right motor mount, I have this this really load sound.

The engine when given a full throttle punch sounds like the crank is supported by a can of rocks. This is not a valve train tick, this is a much louder, more destructive type sound. I don't get any engine codes on my scanner that show any of the two knock sensors are picking up detonation, but you would swear that the motor was going to detonate it self apart.

The other thought I had was that the Kleemann header and custom exhaust was pulled off the one side when the mount broke and the motor wasn't supported properly. I did spend some time moving the exhaust pipes around a little to try and make sure that the pipes weren't hitting on the engine while the motor was moving on the mounts under full throttle.

While driving under light loads you don't get the noise , unless you pull away from a stop a little sharply. I have had a few engine codes of PO170 and PO173 which I have had before and never came with this kind of noise and usaully show up at near idle speeds.

Anyone have any thoughts on this? Carl, Rich, PTE, it is driving me nuts.

Jeff

silence

i had this briefly after my supercharger install. I thought it was the supercharger hitting the inner fender or perhaps the guts of the supercharger flying around- but later ruled that out. After a little bit it just went away...

it was worst when wheels were turned to the right.

sounded absolutely awful...

ProjectC55

Jeff I don't know what those engine codes are.
If the mount is broken it's possible that you could have cracked the header somewhere on the drivers side. It could have hit anything from the steering pump etc. You know how tight and complex the drivers side setup is as it goes to the downpipe(while trying to avoid the steering pump) and then to the crosspipe as well. I'd recheck the header and see if it has a crack. AMG_Rider has a similar problem with his E55K with the noise and a CEL. It looks like he cracked his Kleemann header somewhere (hence his CEL and noise)after hitting an enormous pothole.

However,it's hard for me to say without you providing a sound clip of the noise. Perhaps Rich or Patty could chime in, but I would advise you to pm them. That I find is the best way to get in contact with them.

Good luck and I hope you find the problem.

PTE

Hi Jeff: Mann Thats one bad N/A . You got to find a way to chain the monster down You replaced the Left & Right Mounts & a Right mount wing plate!! I think the new mounts may be a little stiffer , (Being new) , Than the old worn mounts. >They get softer and more complyint with use. On my engines right mount , wing plate .A heat shield is mounted on top the the wing plate & uses the upper mount bolt to hold it in place. I had to refit mine so it would not rattle or contact the headers. A 20 oz Dead blow hammer works well here. If your heat sheild is between the mount & underneath the wing plate. This might be your noise issue. Sounds like some sort of heat sheild is touching somewhere. I have doubled my mount life by swapping them back and forth. One side is getting stretched , while the other side is getting compressed. Kinda of a pain in the Ars. but now the compressed one is getting stretched & visa versa for the stretch one , But effective Cheers ___PTEngineering

speedybenz

Pat, thanks for the reply. I do think it is something in those areas along with a malfitting header that is causing the rattle. Plus I think I may have a small crack in the header somewhere.

I think I am pulling the whole exhaust off this weekend.

I will let you know what I find.

My worst thoughts are that it also sounds very similar to a worn out upper rod bearing. Except on my Superbike motors where we had this issue with some bad rods it would make this sound even when in neutral and the engine was rev'ed. But I do not here this on this motor.

Jeff

ProjectC55

That would be odd. If it sounds like that or that it's coming from that area ,I would not be surprised if the damage is somewhere near the flange of the drivers side header or something.

silence

did you find it?

my car exhibited a bit of this noise (or something similar) again this weekend for a bit.

only does it under heavy load and only when pulling away from a stop or low speed. Will not do it if i'm already moving quickly even if i floor it. will not do it if i don't get into the throttle fairly hard. it is worse when turning left and i belive that turning right hard actually prevents it from happening.

my initial thought was something wrong with supercharger or that it was hitting inner fender but was able to determine that was not the case.

can it be sagging motor mount allows something low on the motor to hit somewhere? it's a bit confusing.