michel j

As I said earlier, I feel the vibration only slightly in the shifter, but it is mainly the whole car. When I first got the car in 2008, it had a cone filter with K and N. The vibration was more intense then. I replaced it with a stock airbox and it smoothed it out greatly. I may be nitpicking but I just don't think it is right. I can even sense it in neutral just a bit. I am thinking or removing both belts and running it briefly just to see if that makes a difference.
One more observation is the two vaccum solenoids are pierburg and the connectors to them show a Mercedes three star symbol. I wonder if this is related. is there anything I can do to check the vaccum system and solenoid operation. I have checked that the resonance flag opens and closes when turning ignition on and off (at least I can hear it).

The clutch, DMF, and pressure plate are my last resort because of $ so looking elsewhere for now.

Help

michel j

Well after puting up with the vibration for 2 years, I am going to replace the DMF with a LWF setup. I am hoping those who recommended this are correct in their diagnosis.

The clutch and flywheel were removed yesterday and I am able to share some photos. My car has 109K miles (mostly highway, I am told) and it appears the clutch/flywheel was original.

The clutch disc is basically worn almost to the rivets and the flywheel/PP contact surfaces show many hot spots. It was time to replace them anyway.

My wrench says that my flywheel does not seem too bad(except for the hot spots). It has the normal amount of twist, in fact less than he would have expected considering the mileage.

Hopefully I will know by tomorrow if I have the dreaded stalling issues.

michel j

Well, I drove my car today after the clutch and flywheel replacement and the firsts results are in. The good news is that my car has not staled... yet. It takes a little longer for the idle to stabilize when cold and I did not find a huge difference in noise levels from the transmission. The lighter flywheel certainly makes the car more responsive. I have not gone for a very long ride yet, but, so far I am very pleased.

The vibration, however, is STILL THERE

My wrench will remove the fan belts and have another look around. It could be normal? or maybe a engine harmonic issue.

Any other suggestions appreciated.

michel j

Removed all belts and ran the engine VERY briefly and vibration/resonance is still there. It starts at about 4300 RPM until redline. I can feel it so much more with windows closed. It is like an angry sound, not smooth, maybe resonant with the internal cavity of the car. I am wondering if this is normal for this car?

firesm

I think at this point, with all of the work you've had done to the car, you need to get some serious driving time in other cars to see if what you are hearing is normal. You should make sure that the other cars are similar in set up to yours - year, exhaust, LWF etc.. And have the owners of the other cars drive yours and give their opinions. It's pretty hard to diagnose sound problems on the internet - even with sound clips. In the end, if there is still no cure, you can always put a set of Fabspeed Supercups on and you'll never hear anything from your car but exhaust (and resonance and droning at 3k rpm). Good luck!

michel j

Attended cars and coffee this AM in Irvine. The car is so much more responsive and fun with the LWF The first to 2nd gear shift is not near as bad. No stalling issues at all. Like everyone says you need to adjust your driving style a bit, but, not bad.
The main drawback is the gear noise in neutral, clutch out and at start up until 2500 RPM.

I still have the resonant vibration between 4300 and 4700 RPM. I could really hear is with windows closed. Almost like something is a bit loose and vibrating at those frequencies. Then again, it could be normal engine vibration.

MarkD

sorry if you have already answered this but what engine mounts do you have?

michel j

I replaced engine mounts with stock ones

Next steps;

- plug holes that were drilled in air box
- remove pipe that sucks clutch dust from transmission housing( is there a down side to this)
- check again for anything loose that may be vibrating at those frequencies
- replace fuel pump that is whinning just a bit
- clean injectors
- muffler replacement with Fister II

NC TRACKRAT

Have re-read all your posts but can't find that you've got the vibration while at rest, i.e., just revving the engine above 4300 rpm. Are you sure it's not a suspension-related problem? Wheel imbalance, out-of-round rim, fault in tire, wheel bearing, mis-alignment. etc.? Even uneven torque on wheels can cause wierd stuff.

mongrelcat

Try Callas in Torrance?
http://www.callasrennsport.com/

or Hergesheimer in Lake Forrest;
http://www.hergesheimer.com/

Mike J

A resonance problem like this one is tough to find for sure. Obviously, all the exhaust has been gone over and checked, right? It can be a subtle as worn baffles in the mufflers, and they vibrate at certain RPM's because of the wave pulses in the exhaust. If it occurs in gears 1-2-3 at the same RPM, then its not the running gear (suspension, hubs, wheels), and local to the engine. If you tired it with all the belts off, then its not alternator/A/C/Fan, and with a new flywheel/clutch, there is not much else other than power steering pump and the internals of the engine.

A quick check to see if its the mufflers (and I have encountered this) is to take them off, and run the car...nice and loud but at least you can see if it still exists.

Does it do it with the clutch in and revved up while not moving, or does it need load?

Cheers,

Mike

michel j

Vibration can be felt at rest especially with windows up, in neutral/clutch out,and out of gear/clutch in. This happens with load and without at any speed. I cannot detect it in first gear because engine speed goes through the RPMs too quickly.

Mufflers installation checks have been done and done again a second time when valve cover gaskets were replaced.

"A quick check to see if its the mufflers (and I have encountered this)"

WOW, The mufflers idea is a good one. Actually I was thinking about that last night, that is why I brought up the Fister II on my list. I personally feel my mufflers are a tad quiet
I am not sure running without mufflers would isolate the problem, but, maybe.

Wonder is there is a difference in sound between the two types of OE muffers Bischoff and Gillette?

Mike J

There is not too much difference between the two stock mufflers. If you do Fister's, the sound may overpower the resonance, and you will be home free.. :-)

Definitely sounds isolated to the engine side, so there are only a few options without tearing the engine apart. Can you record or describe the resonance better? Have you had someone or you stand by the engine while someone resonates the engine so you can locate it (you can use a mechanics stethoscope).

Cheers,

Mike

TCallas

Have your technician perform a cylinder balance test and an exhaust gas analysis to try and isolate whether it is a combustion misfire or not. Make sure the crankshaft pulley isn't bent.

Tony Callas

willc

Any updates on this, I know it's been a long time? I have the same EXACT situation happening and would love to know if your issue was ever resolved.