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Old 05-08-2021, 12:40 AM   #1
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Engine vibrations

My box was in the workshop.

Got new DMF, clutch and IMS bearing.

Since than i have engine vibrations starting at around 2 to 2.5 rpm upwards. And they are getting worse.

Yesterday when cold starting the car i've got a rattle noise for 2 to 3 seconds. Sound like a timing chain was banging against the engine housing. At first sight to me that means a problem with the chain tensioners.

Is it possible that that damn workshop has interchanged the 3 chain tensioners (so they are not in there original position) and that is causing the engine to vibrate at higher rpms?

Thanks, Markus

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Old 05-08-2021, 04:22 AM   #2
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Originally Posted by Smallblock454 View Post
My box was in the workshop.



Got new DMF, clutch and IMS bearing.



Since than i have engine vibrations starting at around 2 to 2.5 rpm upwards. And they are getting worse.



Yesterday when cold starting the car i've got a rattle noise for 2 to 3 seconds. Sound like a timing chain was banging against the engine housing. At first sight to me that means a problem with the chain tensioners.



Is it possible that that damn workshop has interchanged the 3 chain tensioners (so they are not in there original position) and that is causing the engine to vibrate at higher rpms?



Thanks, Markus
What's a dmf?

The cams have to be locked down when the ims is replaced - if they didn't do this then the timing could be all off. I'm not sure if that would cause a vibration but it would definitely run rough (and you wouldn't have much power from the motor either)

Does the vibration happen with the clutch pressed in and revving the motor? If it doesn't, Could the clutch be off balance and that's causing the vibration?


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Old 05-08-2021, 06:00 AM   #3
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DMF = Dual Mass Flywheel

Smallblock, I’d get that thing back to the shop that did the work ASAFP.

ASAFP = As Soon As Fricken Possible

Last edited by paulofto; 05-08-2021 at 06:02 AM.
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Old 05-08-2021, 06:01 AM   #4
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Quote:
Originally Posted by Smallblock454 View Post
My box was in the workshop.



Got new DMF, clutch and IMS bearing.



Since than i have engine vibrations starting at around 2 to 2.5 rpm upwards. And they are getting worse.



Yesterday when cold starting the car i've got a rattle noise for 2 to 3 seconds. Sound like a timing chain was banging against the engine housing. At first sight to me that means a problem with the chain tensioners.



Is it possible that that damn workshop has interchanged the 3 chain tensioners (so they are not in there original position) and that is causing the engine to vibrate at higher rpms?



Thanks, Markus
You ask if the shop interchanged the tensioners, but replacing tensioners isn't on your list of work performed. I'm somewhat confused by that. Did they replace tensioners?

I'd focus on what they changed/ touched.

Why did you replace the dmf? What were you trying to solve? Was it replaced with an oem unit? Was it new or used?

Ike asks a very good question: clutch pedal in or out, any change?

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Old 05-08-2021, 06:20 AM   #5
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Originally Posted by paulofto View Post
DMF = Dual Mass Flywheel

Smallblock, I’d get that thing back to the shop that did the work ASAFP.

ASAFP = As Soon As Fricken Possible
Ahhh, I've never seen it abbreviated like that.

Definitely back to the shop. My bet is on the flywheel or clutch

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Old 05-08-2021, 07:02 AM   #6
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Originally Posted by paulofto View Post
DMF = Dual Mass Flywheel

Smallblock, I’d get that thing back to the shop that did the work ASAFP.

ASAFP = As Soon As Fricken Possible
I would, but i have no more trust in that workshop. My car was there 3 times now and after the 1 and 2 workshop visit there were a lot of other things wrong with the car that were not wrong before.

They have already changed DMF, clutch, clutch basket and so on 2 times.

Vibration is still there and getting worse.

And the best is that they say there is no vibration.

Quote:
Originally Posted by maytag View Post
You ask if the shop interchanged the tensioners, but replacing tensioners isn't on your list of work performed. I'm somewhat confused by that. Did they replace tensioners?

I'd focus on what they changed/ touched.

Why did you replace the dmf? What were you trying to solve? Was it replaced with an oem unit? Was it new or used?

Ike asks a very good question: clutch pedal in or out, any change?

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Clutch and DMF were worn.

Tensioners weren't on the list. They talked me into changing the IMSB, so in the end i agreed. The've used an open roller bearing. To change the ISMB they needed to lock the chains and remove the tensioners.

Because the engine was running absolutely smooth an without any vibrations before, there must be something wrong. And i never ha a chain rattle before.

So i wonder if they might "intermixed" (put the 3 tensioner in the wrong place) the chain tensioners. I don't know if it's technically possible, but to my knowlegde the length and tension is a little bit different. And i don't know if that can cause the vibrations at 2 to 2.5k up.

And i never had a noise from the chains before, when starting the car.

Regards, Markus
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Last edited by Smallblock454; 05-08-2021 at 07:05 AM.
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Old 05-09-2021, 07:11 AM   #7
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I would, but i have no more trust in that workshop. My car was there 3 times now and after the 1 and 2 workshop visit there were a lot of other things wrong with the car that were not wrong before.



They have already changed DMF, clutch, clutch basket and so on 2 times.



Vibration is still there and getting worse.



And the best is that they say there is no vibration.







Clutch and DMF were worn.



Tensioners weren't on the list. They talked me into changing the IMSB, so in the end i agreed. The've used an open roller bearing. To change the ISMB they needed to lock the chains and remove the tensioners.



Because the engine was running absolutely smooth an without any vibrations before, there must be something wrong. And i never ha a chain rattle before.



So i wonder if they might "intermixed" (put the 3 tensioner in the wrong place) the chain tensioners. I don't know if it's technically possible, but to my knowlegde the length and tension is a little bit different. And i don't know if that can cause the vibrations at 2 to 2.5k up.



And i never had a noise from the chains before, when starting the car.



Regards, Markus
I've not changed an ims personally, but from the instructions I have seen it isn't necessary to (or really even understandable why someone would) remove the chain tensioners during that procedure.

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Old 05-09-2021, 07:32 AM   #8
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Their removal releases the chains so that the IMS shaft centers in the case opening rather than being pulled to one side by the chains.
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Old 05-09-2021, 09:32 AM   #9
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Their removal releases the chains so that the IMS shaft centers in the case opening rather than being pulled to one side by the chains.
That's interesting. One thing I have read about IMS bearing failure is that some shafts (and hence the bearing) seem to be off centered and that this eccentricity leads to bearing failure. Do you think that removing the chain tensioners before IMSB install and then reinstalling at the end eliminates this problem?

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Old 05-09-2021, 10:20 AM   #10
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The tensioners as well as the engine case are marked for which goes to which location. If in double lift it up and take a look at both. Burner has some good videos on the subject on youtube.
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Old 05-09-2021, 10:49 AM   #11
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Originally Posted by ike84 View Post
That's interesting. One thing I have read about IMS bearing failure is that some shafts (and hence the bearing) seem to be off centered and that this eccentricity leads to bearing failure. Do you think that removing the chain tensioners before IMSB install and then reinstalling at the end eliminates this problem?

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Absolutely not. Once everything is reassembled, off center shafts, or engine cases, will still force side loads on the bearing as the real problem has not been addressed.

Removal of the hydraulic tensioners is essential during an IMS retrofit because not removing them, as many have discovered the hard way, forces the shaft to one side and prevents removal of the bearing, and can also lead to one or more chain jumping time, which leads to no end of problems. We have had more than one totally failed retrofits flat bedded to the shop because the owner’s never bothered to read the instructions for doing a retrofit, and then ended up paying us thousands of completely unecessary dollars to put the car back together.
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Old 05-09-2021, 07:02 PM   #12
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Just outside the box... Could it be caused by motor mounts?

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