Chops Posted April 15, 2017 Share Posted April 15, 2017 Just purchased this 2005 audi a4 avant 2ltr tdi last week and im having a few teething issues! The car has covered 81k with fsh and has had the head and oil pump replaced at some point but not at a dealership (guy who i bought car from owned a garage and done it themselves) when driving in any gear,but only in low revs,upto 2000rpm, there is a vibration/rattle/knocking. Its hard to describe the noise but its only in the low revs when driving. It doesnt make the noise on idle or past 2000rpm!! If your very gentle on the throttle it doesnt make the noise either! I work at a vw dealership and have had the mastertech take a drive in it and he cant decide what the noise is but says its a "pinking sound"and it could be from being badly timed back up when the cam belt was done or it could be the flywheel (or something completly different!!) Now with myself not being mechancally minded at all,im at a loss at what to do first, so wondered if anyone has had a similar issue or could help with any sort of diagnosis. Thanks Quote Link to comment Share on other sites More sharing options...
Chops Posted April 15, 2017 Author Share Posted April 15, 2017 Out of curiosity.... would the flywheel even still make this kind of noise when driving? seems strange that it is only upto 2000rpm in every gear then it goes and sounds normal! Quote Link to comment Share on other sites More sharing options...
Chops Posted April 16, 2017 Author Share Posted April 16, 2017 One thing i noticed today was that the noise didnt happen in any gear or rpm within the first 2 minutes of start up (maybe 1 mile thru town) i did notice on start up tho that there was bit of white/grey smoke on ignition but nothing while driving. Quote Link to comment Share on other sites More sharing options...
Dan3222 Posted April 17, 2017 Share Posted April 17, 2017 Does it make the noise in neutral, when reving the engine? Or is it just when actually driving? Quote Link to comment Share on other sites More sharing options...
Chops Posted April 17, 2017 Author Share Posted April 17, 2017 1 hour ago, Dan3222 said: Does it make the noise in neutral, when reving the engine? Or is it just when actually driving? No noise on idle or reving its Just when actually driving. Quote Link to comment Share on other sites More sharing options...
Dan3222 Posted April 17, 2017 Share Posted April 17, 2017 ok, so the mastertech guy could well be right. When u start the car cold, (other readers Please correct me if I wrong here) the timing is slightly advanced until the engine warms up. Then it goes to a normal timing. This could explain why it's not doing it when cold. Maybe the timing belt is out by a tooth? other is DMF (assuming that's what's fitted) it can give similar symptoms. Quote Link to comment Share on other sites More sharing options...
Chops Posted April 17, 2017 Author Share Posted April 17, 2017 23 minutes ago, Dan3222 said: ok, so the mastertech guy could well be right. When u start the car cold, (other readers Please correct me if I wrong here) the timing is slightly advanced until the engine warms up. Then it goes to a normal timing. This could explain why it's not doing it when cold. Maybe the timing belt is out by a tooth? other is DMF (assuming that's what's fitted) it can give similar symptoms. Thanks. I guess ill start with changing the timing belt again as it the cheaper option. The dmf does have a very slight rattle on idle but this is a totally different sound to the engine noise so not sure it could be related or not. Just to throw a few other option out there, could it be an injector? Or the oil pump chain? remember im not mechanically minded so dont know if these options would make this noise or not. Its just what ive read on other forums Quote Link to comment Share on other sites More sharing options...
Dan3222 Posted April 17, 2017 Share Posted April 17, 2017 It's just you say there is 3 things, 1,judder and 2, vibration could be fueling issues for sure, though injector wise I would guess the vibration would be more obvious, particularly at lower revs. Its thing 3, the noise. That's what's throwing me, unless there are actually two issues?? If the noise is caused by a pump chain I don't see how that would cause the physical symptoms. Head scratcher. If it is two separate issues, then the judder could also be coming from a drive shaft. Typically if the inner joint has wear you will get vibrations that are more speed specific but they are exaggerated on acceleration till a certain speed and then it goes away. They wear at a specific point on the shaft when at temperature. So, when cold the bearings are not in their usual place. When warm they reach said place and can wear the shaft. So the bearings lock into the wear marks and that creates a judder at certain speeds. what does it behave like on harder acceleration? In each gear? Quote Link to comment Share on other sites More sharing options...
Chops Posted April 17, 2017 Author Share Posted April 17, 2017 Just found out that when the head was replaced on my car, they also changed the oil pump from the chain driven type to the geared pump. So can that now be eliminated? Quote Link to comment Share on other sites More sharing options...
Chops Posted April 17, 2017 Author Share Posted April 17, 2017 19 minutes ago, Dan3222 said: It's just you say there is 3 things, 1,judder and 2, vibration could be fueling issues for sure, though injector wise I would guess the vibration would be more obvious, particularly at lower revs. Its thing 3, the noise. That's what's throwing me, unless there are actually two issues?? If the noise is caused by a pump chain I don't see how that would cause the physical symptoms. Head scratcher. If it is two separate issues, then the judder could also be coming from a drive shaft. Typically if the inner joint has wear you will get vibrations that are more speed specific but they are exaggerated on acceleration till a certain speed and then it goes away. They wear at a specific point on the shaft when at temperature. So, when cold the bearings are not in their usual place. When warm they reach said place and can wear the shaft. So the bearings lock into the wear marks and that creates a judder at certain speeds. what does it behave like on harder acceleration? In each gear? When Driving harder the noise doesnt happen because the revs never drop below 2000rpm. Even at higher speeds in 6th gear when cruising at 2000rpm the noise isnt there. Likewise,if your light footed on the throttle and dont floor it then the noise doesnt happen either. I will try to get a sound clip of the noise and post it up on here. Quote Link to comment Share on other sites More sharing options...
Chops Posted April 17, 2017 Author Share Posted April 17, 2017 This is a sound clip/video of the noise while driving. Rough upto 2000rpm then sounds normal IMG_1655.MOV Quote Link to comment Share on other sites More sharing options...
Chops Posted April 18, 2017 Author Share Posted April 18, 2017 Try again! This is the video of the noise from 1000rpm upto 2000rpm Quote Link to comment Share on other sites More sharing options...
Dan3222 Posted April 18, 2017 Share Posted April 18, 2017 It's really difficult to make it out. Actually sounds quite good lol. Pick up is quite good though. Let's hope it's something simple. Quote Link to comment Share on other sites More sharing options...
Dan3222 Posted April 18, 2017 Share Posted April 18, 2017 My pal has listened to, he said check timing too! Quote Link to comment Share on other sites More sharing options...
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