Need help with diagnosis --> grinding noise after 4k RPM
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V12TT
Need help with diagnosis --> grinding noise after 4k RPM
With the new pulley in under WOT after 4k RPM's I start hearing a really loud grinding noise from 4-7k RPMs until it shifts up with a jerk. Checked the transmission fluid, it's up full and it's new. Torque converter starting to give up? 
There is also alot of power loss when it makes the noise.
There is also alot of power loss when it makes the noise.
Last edited by benz_addict; Oct 15, 2010 at 04:30 AM.
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From: London, UK
No longer stock '06 E55, A3 3.2 Quattro, GLE 400d, R107 280SL, Golf Polo
Lets hope its not detonation....
I had something similar recently in a WOT run, but ended up assigning this to a leaking exhaust - has not happened again. I also thought it could be one of the CAT internals getting loose and dislodging (causing too much back pressure and the exhaust leak developing.)
This happened soon after I installed whe W/I system and my theory goes along the line that the W/I cleaned out the intake and cylinders and the gunk blocked the CAT/S, higher back pressure dislodged CAT core and exhaust leak developed. I am not sure how valid this is as I am not sure how much gunk would have got burned up in combustion. Ill be sending a scope into the cylinders when I change the plugs....
I had a small oil leak too on the top of one of the cam covers - but thats been there a little while (just fixed) and think thats not related.
Mine sounded like a rattle/grating sound, and also a loss of power.
I had something similar recently in a WOT run, but ended up assigning this to a leaking exhaust - has not happened again. I also thought it could be one of the CAT internals getting loose and dislodging (causing too much back pressure and the exhaust leak developing.)
This happened soon after I installed whe W/I system and my theory goes along the line that the W/I cleaned out the intake and cylinders and the gunk blocked the CAT/S, higher back pressure dislodged CAT core and exhaust leak developed. I am not sure how valid this is as I am not sure how much gunk would have got burned up in combustion. Ill be sending a scope into the cylinders when I change the plugs....
I had a small oil leak too on the top of one of the cam covers - but thats been there a little while (just fixed) and think thats not related.
Mine sounded like a rattle/grating sound, and also a loss of power.
Thread Starter
MBWorld Fanatic!
Joined: Jan 2007
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From: Toronto
V12TT
Lets hope its not detonation....
I had something similar recently in a WOT run, but ended up assigning this to a leaking exhaust - has not happened again. I also thought it could be one of the CAT internals getting loose and dislodging (causing too much back pressure and the exhaust leak developing.)
This happened soon after I installed whe W/I system and my theory goes along the line that the W/I cleaned out the intake and cylinders and the gunk blocked the CAT/S, higher back pressure dislodged CAT core and exhaust leak developed. I am not sure how valid this is as I am not sure how much gunk would have got burned up in combustion. Ill be sending a scope into the cylinders when I change the plugs....
I had a small oil leak too on the top of one of the cam covers - but thats been there a little while (just fixed) and think thats not related.
Mine sounded like a rattle/grating sound, and also a loss of power.
I had something similar recently in a WOT run, but ended up assigning this to a leaking exhaust - has not happened again. I also thought it could be one of the CAT internals getting loose and dislodging (causing too much back pressure and the exhaust leak developing.)
This happened soon after I installed whe W/I system and my theory goes along the line that the W/I cleaned out the intake and cylinders and the gunk blocked the CAT/S, higher back pressure dislodged CAT core and exhaust leak developed. I am not sure how valid this is as I am not sure how much gunk would have got burned up in combustion. Ill be sending a scope into the cylinders when I change the plugs....
I had a small oil leak too on the top of one of the cam covers - but thats been there a little while (just fixed) and think thats not related.
Mine sounded like a rattle/grating sound, and also a loss of power.
I got new high flow primary cats installed (from eurocharged) I thought they got clogged and creating too much back pressure but I went underneath the car and used a mallet on it and couldn't hear any lose particles. You think too much gunk is trapped in there? I think the cats could be damaged somehow this is weird it's only need 2 weeks since install. I also checked everything else under the hood all fluids, any loose parts, took the air box out and searched for vacuum leaks. All looks good. I'm starting to think it's either the clogged cats creating back pressure or the timing is off? Feels like it's miss firing causing to lose power and making machine gun fires. It drives fine if I keep it under 3k rpms.
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V12TT
bump.
Getting CYL 1 misfire. Replaced all spark plugs. Replaced the CYL1 ignition coil and wires and checked wiring harness. Result: CYL 1 misfire still detected.
Any input appreciated.
Getting CYL 1 misfire. Replaced all spark plugs. Replaced the CYL1 ignition coil and wires and checked wiring harness. Result: CYL 1 misfire still detected.
Any input appreciated.
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From: Ontario, Canada
W204 C63 R171
Do you also repair rolex's with a mallet lol
Wacking your cats with a mallet not the best idea...
W/I is water injection judgeing by his sig line...
Pardon my ignorance but does your supercharger have an electric clutch? Does it happen to turn on above 4000RPM?
Also judgeing by the fact you just put a new pully on you might want to look into that make sure its on tight etc... maybe take it off and put the old one back on and see if the problem exists...
no help on puremb with this
Wacking your cats with a mallet not the best idea...
W/I is water injection judgeing by his sig line...
Pardon my ignorance but does your supercharger have an electric clutch? Does it happen to turn on above 4000RPM?
Also judgeing by the fact you just put a new pully on you might want to look into that make sure its on tight etc... maybe take it off and put the old one back on and see if the problem exists...
no help on puremb with this
Last edited by andrew c230k; Oct 20, 2010 at 07:38 PM.
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Thread Starter
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From: Toronto
V12TT
**UPDATE** Problem found.
So cut out my primaries just now only to find they lodged their internals back into the exhaust piping somewhere, gutted out completely by the backpressure and therefore clogging the exhaust system somewhere. Now the hard part, where are the cat internals honeycomb bits stuck? I still got the resonators in place but no secondaries still have stock mufflers. Car runs and drives FINE straight pipe out from headers, but loud as ****. Pics soon.
I know this same thing happened to exotic-metal55. This is what happens when your beast is too powerful haha.
So cut out my primaries just now only to find they lodged their internals back into the exhaust piping somewhere, gutted out completely by the backpressure and therefore clogging the exhaust system somewhere. Now the hard part, where are the cat internals honeycomb bits stuck? I still got the resonators in place but no secondaries still have stock mufflers. Car runs and drives FINE straight pipe out from headers, but loud as ****. Pics soon.
I know this same thing happened to exotic-metal55. This is what happens when your beast is too powerful haha.
Last edited by benz_addict; Oct 21, 2010 at 07:07 PM.
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MBWorld Fanatic!
Joined: Jul 2005
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From: London, UK
No longer stock '06 E55, A3 3.2 Quattro, GLE 400d, R107 280SL, Golf Polo
Just got my Kleeman headers on and right bank cat looked fine - did not have chance to check left side where exhaust leak developed. but will check tnite. Hopefully (I guess) this was / is my problem too.
Thread Starter
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From: Toronto
V12TT
Fixed
Problem fixed. Cat's removed (what was left anyway). Custom 3" downpipes all the way to 3" dual x muffler to resonators, to stock mufflers.
Results... It just prrrrss SLR.
Results... It just prrrrss SLR.
