amf tdi self destuct

hi I have an amf tdi engine with a massive vibration problem. Bad enough to fracture the front pipe of the exhaust and vibration felt thruout whole vehicle.scanned with vcds no reported errors or codes . Car has a solid flywheel I have replaced the injector harness whitch has made no diifference.replaced fuel filter and fresh fuel no difference scanned again with vcds and no errors found all injectors working well within tolerances anyone out there experienced similar problems as I am out of ideas with this
 

Robin_Cox

Member
Oil pump chain / counterbalance shaft positioning slipped? This is essential to resolve the dynamics of the 3 cylinder engine, so if this has gone out of position and is resonating with / enhancing the natural imbalance it would be pretty horrific. I'm no expert, but the Tdi balance shaft / oil chain debate has been discussed a few times over the past couple of years so this is what your situation sounds like to me.


parts 25/26 - driven by the chain (part 20).
 
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depronman

Member
Plus one for Robins diagnosis
This would be my starting point
What miles / service history ? Although this appears to not be a great factor in chain/guide wear. As the car been used for lots of short journeys ?


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Menno

A2OC Donor
Can you give additional information? Which Rev range, while driving, stationary, when is it most present, etc.

For instance:
If one of the inner CV joints are knackered it gives vibration to the whole car too, especially in higher gear and/or uphill driving.
 

kp 115

Member
Have you checked all of the engine/gearbox mounts for movement?
hi I have an amf tdi engine with a massive vibration problem. Bad enough to fracture the front pipe of the exhaust and vibration felt thruout whole vehicle.scanned with vcds no reported errors or codes . Car has a solid flywheel I have replaced the injector harness whitch has made no diifference.replaced fuel filter and fresh fuel no difference scanned again with vcds and no errors found all injectors working well within tolerances anyone out there experienced similar problems as I am out of ideas with this
Hi Michael,
When you say fractured the front pipe is that the actual tube or the flexible coupling as the later is a common failure point, my first port of call would be the dog bone mount on the bottom of the gearbox as this stops the engine swinging alarmingly on the top two mounts & is a simple fix by checking condition of rubber bushings & ensuring correct torque settings applied to the bolts, Febi make a replacement part for the polo which fits once a bracket is swapped over (I have part numbers at home if that helps)
Hth
Keith.
 
hi thankyou for your input all mounts in good order, drive shafts ok vibations present throughout rev range, new cambelt and clutch fitted vcds says engine timing ok in fact no faults shown vehicle stationary worst vibration at 1200 to 1800 rpm
 

depronman

Member
Almost certainly the chain as jump a tooth or two or the guide is very badly worn and the chain stretched so badly that the balance shaft timing is now out
I would imagine it is not doing the engine any good running in this out of balance state so one to resolve soonest
It’s a sump off job to check the timing of the chain but if miles are over 100k then get the parts and change the chain, sprockets and guides
If the belt as not been changes recently then worthy also doing the belt and water pump whilst your in there as the belt as to come off anyway
Paul


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dj_efk

A2OC Donor
Agree it sounds like the balance / oil pump drive chain has jumped out of alignment - my strong advice is don’t run the engine again until you’ve done the work described above; and count yourself lucky the chain didn’t jam when it jumped - that has been known to render the crank scrap!
 
Thankyou for everyone help .I removed the sump to find that the balance was 180 degrees from the position on the chain from where it should have been, All sprockets look in good order I will replace oil pump as l have a used spare one and also new chain and tensiner guide assy.Fingers crossed should cure the problem still waiting for new parts to arrive (febi)
 

depronman

Member
180 degrees exactly?
If so then that sounds like someone as removes the chain and put it back together incorrectly timed
It seems unlikely that the balance shaft would jump a number of teeth and end up exactly 180deg out of position
Do you have history of the engine?
What is the state of the guides?

Sorry for so many questions just trying to piece the puzzle back together

Paul


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