Exhaust vibration after straight piping secondary cat
08-09-2017, 09:34 AM
#26
Member
Thread Starter
My car had an odd vibration in drive inidle.
I had a new maf, trans mount, and engine mounts are still solid.
The car would have a very slight vibration, kind of irregular tempo.
Replaced two 02 sensors that I could get to and its gone but its still there while in park. Kind of odd and not 100% sure thats your issue but its worth looking into.
All 02 sensors are different part numbers on my car(98 c43 amg), its probably the same with yours
I had a new maf, trans mount, and engine mounts are still solid.
The car would have a very slight vibration, kind of irregular tempo.
Replaced two 02 sensors that I could get to and its gone but its still there while in park. Kind of odd and not 100% sure thats your issue but its worth looking into.
All 02 sensors are different part numbers on my car(98 c43 amg), its probably the same with yours
08-23-2017, 10:17 AM
#27
Member
Thread Starter
I had my car checked yesterday with the 1000-1200 rpm vibration/drone. The mechanic used an endoscope to look for the sound source.
He found the drone to be difficult to locate and his two main suspects were the torque converter in the gearbox and the engine oil pump.
He also checked the engine parameters through Star Command saying that everything was perfect.
I also had my engine oil changed to Shell Helix Ultra 5W40 (the previous oil was TITAN Supersyn LONGLIFE 0W40). The drone seemed to have diminshed but then it appeared again.
Anyways the main suspect is the torque converter as i'm getting some shudder from time to time and erratic gear shifts.
The transmission fluid level is ok but the fluid is very dark in color and is in need of replacement.
He found the drone to be difficult to locate and his two main suspects were the torque converter in the gearbox and the engine oil pump.
He also checked the engine parameters through Star Command saying that everything was perfect.
I also had my engine oil changed to Shell Helix Ultra 5W40 (the previous oil was TITAN Supersyn LONGLIFE 0W40). The drone seemed to have diminshed but then it appeared again.
Anyways the main suspect is the torque converter as i'm getting some shudder from time to time and erratic gear shifts.
The transmission fluid level is ok but the fluid is very dark in color and is in need of replacement.
08-30-2017, 04:01 AM
#28
Member
Thread Starter
An update on my problem:
The technician disconnected the torque converter from the flywheel to pinpoint whether it's the gearbox or the engine causing the vibration.
Bad news - the vibration was still there and it was coming from the area where the oil pump is located. This happens mostly when the engine is hot.
Unfortunately the car is not under warranty so I'm paying for the repairs out of my wallet.
I'm ordering a new oil pump, oil mup chain and guides.
I've never thought that I would have to replace the oil pump on a car with only 37000 miles on the odometer.
The technician disconnected the torque converter from the flywheel to pinpoint whether it's the gearbox or the engine causing the vibration.
Bad news - the vibration was still there and it was coming from the area where the oil pump is located. This happens mostly when the engine is hot.
Unfortunately the car is not under warranty so I'm paying for the repairs out of my wallet.
I'm ordering a new oil pump, oil mup chain and guides.
I've never thought that I would have to replace the oil pump on a car with only 37000 miles on the odometer.
08-31-2017, 08:45 AM
#29
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09 C63 AMG
Are you tuned? I had a similar issue when I had my headers installed. Went through a couple cycles of unplugging the battery and it went away. Was only at low rpm (under 2k) and in any gear.
side note - if you need anything, my engine is being parted out due to a cracked block.
side note - if you need anything, my engine is being parted out due to a cracked block.
08-31-2017, 09:19 AM
#31
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09 C63 AMG
08-31-2017, 09:22 AM
#32
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10-01-2017, 12:18 PM
#33
Member
Thread Starter
An update on my problem, guys:
The vibration appears precisely on 2000 RPMs when acceerating in high gear. I can't figure out whether it's the exhaust or something else, but it's definitely coming from the middle/rear side of the car.
The ones of you who have the secondaries straight piped can you please try accelerating in high gear in manual mode going as slow as possible (4th gear for example) and please report whether you feel any sort of drone/vibration at the 2000 RPM point?
Thanks in advance!
I'd also appreciate any advice regarding how to pinpoint the source. This drone happens only under load and I assume there is no use accelerating the car while on a lift to find the source.
The vibration appears precisely on 2000 RPMs when acceerating in high gear. I can't figure out whether it's the exhaust or something else, but it's definitely coming from the middle/rear side of the car.
The ones of you who have the secondaries straight piped can you please try accelerating in high gear in manual mode going as slow as possible (4th gear for example) and please report whether you feel any sort of drone/vibration at the 2000 RPM point?
Thanks in advance!
I'd also appreciate any advice regarding how to pinpoint the source. This drone happens only under load and I assume there is no use accelerating the car while on a lift to find the source.
10-01-2017, 06:02 PM
#34
Member
Why not remove the centre bar and see if the drone/vibration still occurs?
Are your pipes welded in or clamped in?
i had issues with my headers mid pipes connecting to cat back as it kept slipping off on heating up, hence the vibrations.
It needed few points of welding to keep it in place.
Are your pipes welded in or clamped in?
i had issues with my headers mid pipes connecting to cat back as it kept slipping off on heating up, hence the vibrations.
It needed few points of welding to keep it in place.
10-01-2017, 06:16 PM
#35
MBWorld Fanatic!
If the noise just started when you cut the cats out, I highly doubt you need an oil pump...
Why not have cats put back in and see if it goes away? I agree with the general sentiment here that something may be touching.
Also, if your mounts were just replaced, by an outside shop, they probably did not follow the procedures for installing them without tension in the mounts. Might be a resonance being transmitted due to that which wasn't audible in the exhaust before you removed the cats.
Why not have cats put back in and see if it goes away? I agree with the general sentiment here that something may be touching.
Also, if your mounts were just replaced, by an outside shop, they probably did not follow the procedures for installing them without tension in the mounts. Might be a resonance being transmitted due to that which wasn't audible in the exhaust before you removed the cats.
10-02-2017, 03:28 AM
#36
Member
Thread Starter
Speaking of my oil pump - it's a totally different problem I'm experiencing. It gives out a vibration and weird noises at 1200-1300 rpm (light throttle). The mechanic had the torques converter (wet clutch) disconnected from the flywheel and we ran the engine while the car was on the lift. The vibration was still there and strange noises could be heard from the oil pan area. I was told I need to replace the oil pump.
I don't know whether it's a coincidence or not but I think I began experiencing this problem roughly after the engine mounts replacement.
Are there some specific tension requirements when changing the mounts? They removed my exhaust, pushed up the engine and transmission and replaced the mounts without following the Star procedures.
Now the exhaust drone is a totally separate issue. Like I mentioned in my posts above, it appears at 2000 RPM and increased exhaust drone can be heard on overruns.
The backstory to this is that the exhaust shop I chose to straight pipe my seconary cats inititally did an awful job. I ended up with my exhaust tips barely sticking out of the valance and both pipes touching the supporting bar near the resonator connection.
I made them redo this twice fixing the exhaust tips distance and increasing clearance around the midpipe to resonator connection.
It's ok now but it looks nasty and I had an exhuast leak on one of the flanges of the resonator connection. They put some exhaust paste around it to fix the leak.
The problem occurs when the car and exhaust is hot which leads me to think that I have to completely reweld the midside section of the exhaust at another shop.
This is what my straight pipes initially loked like:
This is what they look like now (You can notice the area where the exhaust leak was. I also made them weld in an interconnection when I was trying to find the reason of the 1200 RPM vibration I mentioned in the begining of this post):
I don't know whether it's a coincidence or not but I think I began experiencing this problem roughly after the engine mounts replacement.
Are there some specific tension requirements when changing the mounts? They removed my exhaust, pushed up the engine and transmission and replaced the mounts without following the Star procedures.
Now the exhaust drone is a totally separate issue. Like I mentioned in my posts above, it appears at 2000 RPM and increased exhaust drone can be heard on overruns.
The backstory to this is that the exhaust shop I chose to straight pipe my seconary cats inititally did an awful job. I ended up with my exhaust tips barely sticking out of the valance and both pipes touching the supporting bar near the resonator connection.
I made them redo this twice fixing the exhaust tips distance and increasing clearance around the midpipe to resonator connection.
It's ok now but it looks nasty and I had an exhuast leak on one of the flanges of the resonator connection. They put some exhaust paste around it to fix the leak.
The problem occurs when the car and exhaust is hot which leads me to think that I have to completely reweld the midside section of the exhaust at another shop.
This is what my straight pipes initially loked like:
This is what they look like now (You can notice the area where the exhaust leak was. I also made them weld in an interconnection when I was trying to find the reason of the 1200 RPM vibration I mentioned in the begining of this post):
10-02-2017, 10:10 AM
#37
Member
Welding the interconnecting plate will just cause the vibrations to be more pronounced.
Looks like the exhaust shop used a smaller diameter pipe for the straight pipe and hence causing the leak. The leak will cause the drone when heated up and expand more.
I would just bring it to a more reputable exhaust place to have to all redone. At least you have peace of mind that it will be done once and for all. Then you can concentrate on fuel pump issue.
Looks like the exhaust shop used a smaller diameter pipe for the straight pipe and hence causing the leak. The leak will cause the drone when heated up and expand more.
I would just bring it to a more reputable exhaust place to have to all redone. At least you have peace of mind that it will be done once and for all. Then you can concentrate on fuel pump issue.
10-02-2017, 12:20 PM
#38
Member
Thread Starter
Welding the interconnecting plate will just cause the vibrations to be more pronounced.
Looks like the exhaust shop used a smaller diameter pipe for the straight pipe and hence causing the leak. The leak will cause the drone when heated up and expand more.
I would just bring it to a more reputable exhaust place to have to all redone. At least you have peace of mind that it will be done once and for all. Then you can concentrate on fuel pump issue.
Looks like the exhaust shop used a smaller diameter pipe for the straight pipe and hence causing the leak. The leak will cause the drone when heated up and expand more.
I would just bring it to a more reputable exhaust place to have to all redone. At least you have peace of mind that it will be done once and for all. Then you can concentrate on fuel pump issue.
That’s exactly what I’ll do. Thank you!
Actually it’s an oil pump issue
I got a phone call today informing me that the part had arrived.
