Chat my A2 tdi sounds like a sewing machine after cambelt change any ideas?

Frank0

Member
Has anyone experienced this? I had my a2 tdi 75bhp cambelt changed in 2019 and as soon as started it it sounded ticking like a sewing machine under load, bit quieter lifting off throttle reminded me of my old di 2.5D smiley transit. I took it back and they checked and said its fine. I've asked two or 3 mechanics since and they all say it sounds like it should or what a pd should sound like. Although few know what it should sound like they say as rare cars. We had it since 16k and first up till 50K and second up to 90K cambelts were fine on this third it sounds wrong, doesn't quite fire up as easily used to be quick turn now turns over once maybe. I'm not imagining it but no-one seems to be able to hear it. Thought if anyone knew or had an idea it'd be on here. cheers Frank.
 

Howey

Member
Has anyone experienced this? I had my a2 tdi 75bhp cambelt changed in 2019 and as soon as started it it sounded ticking like a sewing machine under load, bit quieter lifting off throttle reminded me of my old di 2.5D smiley transit. I took it back and they checked and said its fine. I've asked two or 3 mechanics since and they all say it sounds like it should or what a pd should sound like. Although few know what it should sound like they say as rare cars. We had it since 16k and first up till 50K and second up to 90K cambelts were fine on this third it sounds wrong, doesn't quite fire up as easily used to be quick turn now turns over once maybe. I'm not imagining it but no-one seems to be able to hear it. Thought if anyone knew or had an idea it'd be on here. cheers Frank.
Good place to start would be to check the torsion value, this is the cam to crank timing in effect and lets you know if the fine tuning of the timing is where it needs to be, its been spoke about on the forum and internet in general as same as the 1.9PD. The 1.4 tdi pd is very common accross the vag range.
It might be worth spraying maintenance spray on to the back of the drive belt whilst engine is running to rule out any drivebelt issues
 
I reckon that there is the tiniest whiff if it not being fitted correctly, a tooth out of synch? Sorry for being a bit of a doom monger.

Best of luck

VAS in Bath really do know their stuff and they are actually used by Audi UK.
 

dj_efk

A2OC Donor
To play devils advocate here - how sure are you that the previous belt was correctly fitted? Could it be that the new belt is now correctly fitted / timed in a way that the previous one wasn’t?

I ask as my A2 also ticks under load audibly from the injectors (I assume) - as do many other diesels of the same age or older (Fords are particularly prevalent in my mind so not surprised you name a transit as a comparison) - I’ve just accepted it as part of the character of the car.
 

Frank0

Member
I reckon that there is the tiniest whiff if it not being fitted correctly, a tooth out of synch? Sorry for being a bit of a doom monger.

Best of luck

VAS in Bath really do know their stuff and they are actually used by Audi UK.
cheers, been on since 2019.would it run ok a tooth out? I thought more like an over run pulley or something along those lines.
 

Frank0

Member
To play devils advocate here - how sure are you that the previous belt was correctly fitted? Could it be that the new belt is now correctly fitted / timed in a way that the previous one wasn’t?

I ask as my A2 also ticks under load audibly from the injectors (I assume) - as do many other diesels of the same age or older (Fords are particularly prevalent in my mind so not surprised you name a transit as a comparison) - I’ve just accepted it as part of the character of the car.
we had car from 16k which would be factory belt and second was fine too. always was smoother than now. it's like a tappet rattle but faster like a sewing machine hard to explain. is there a over run pulley tensioner or something on it ?
 

audifan

A2OC Donor
That is the issue trying to decide if it is cam belt or aux belt. In either case a failing or worn idler bearing over tensioned or alternator over run clutch can produce regular noise. The belt itself may be of poor quality or composition and is causing noise. Possible it is water pump noise.
 

Frank0

Member
Good place to start would be to check the torsion value, this is the cam to crank timing in effect and lets you know if the fine tuning of the timing is where it needs to be, its been spoke about on the forum and internet in general as same as the 1.9PD. The 1.4 tdi pd is very common accross the vag range.
It might be worth spraying maintenance spray on to the back of the drive belt whilst engine is running to rule out any drivebelt issues
Hi Thanks, too technical for me unfortunately. lol. it runs ok just thought might be a pulley tension adjustment or something common. but seems not. cheers.
 

Frank0

Member
That is the issue trying to decide if it is cam belt or aux belt. In either case a failing or worn idler bearing over tensioned or alternator over run clutch can produce regular noise. The belt itself may be of poor quality or composition and is causing noise. Possible it is water pump noise.
cheers, yeah all of these spring to mind as can imagine the sound coming from any. it did have an idler pulley a while before the new belt, perhaps the tension is wrong for the new belt, as instantly showed up after belt change.
 

audifan

A2OC Donor
Another possibility is the aux belt was refitted the wrong way round. The belt must run the same direction from fitment so if removed for access there is a possibility it was put back the wrong way round.
 

Howey

Member
Spray some maintenance fluid on the Aux belt whilst engines running if noise goes for a brief time you know your issue and could be the aux tensioner has taken well to being played with
 
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