2008 A4 Avant TDi 2.0 AUTO vibration

[Coop748]

First post so treat me nice!

Above vehicle. I’m second owner. First owner is a very good friend. Car has never been in a collision. Around 156k miles. 

In March 2022 recently fitted timing belt kit tensioner bolt fell out. Engine lunched. 

Top end refurbed. Ran fine. Under load vibrated harshly between 1500 and about 2250 revs at any speed any gear. 
 

Replaced DMF. No change. Replaced clutch box. No change. Replaced drive shafts. No change. 
 

Have now replaced the motor with a pre-owned lump. Bit of a change but still vibrates.

No fault codes on diagnostics. Cruises lovely. Not great under load  

Any suggestions? 

[Stevey Y]

5 minutes ago, Coop748 said:

First post so treat me nice!

Above vehicle. I’m second owner. First owner is a very good friend. Car has never been in a collision. Around 156k miles. 

In March 2022 recently fitted timing belt kit tensioner bolt fell out. Engine lunched. 

Top end refurbed. Ran fine. Under load vibrated harshly between 1500 and about 2250 revs at any speed any gear. 
 

Replaced DMF. No change. Replaced clutch box. No change. Replaced drive shafts. No change. 
 

Have now replaced the motor with a pre-owned lump. Bit of a change but still vibrates.

No fault codes on diagnostics. Cruises lovely. Not great under load  

Any suggestions? 

Hi possible,

engine Hydro mounts especially if they are original check them for oil leakage.

Steve.

 

[Coop748]

1 minute ago, Stevey Y said:

Hi possible,

engine Hydro mounts especially if they are original check them for oil leakage.

Steve.

 

Thanks Steve. 
 

I should have mentioned all mounts have been replaced. 
 

!Removed! mystery. 

[Coop748]

Any suggestions?

Wondered if it could be an injector issue but no fault codes are being thrown up. 

Definitely RPM range related and not speed related as the shudders are in Rev range and not speed range. 

Dead frustrating. 

Edited November 5, 2022 by Coop748

[Steve Q]

Could it be an intermittent issue with the MAF sensor? 

[Coop748]

2 hours ago, Steve Q said:

Could it be an intermittent issue with the MAF sensor? 

Thanks Steve

Not throwing it up on diagnostics but worth a good look.

If I disconnect  the MAF and the car behaves the same would that be a good indication of an issue there?

[Steve Q]

3 hours ago, Coop748 said:

Thanks Steve

Not throwing it up on diagnostics but worth a good look.

If I disconnect  the MAF and the car behaves the same would that be a good indication of an issue there?

I can't say on a more modern, electrical controlled car so to speak. But when I had idling and stalling issues on a old Volvo 940 2.3 petrol a few years ago, when I disconnected the MAF it ran better which proved it was a faulty MAF. Which my diagnosis proved correct. 

[Coop748]

1 hour ago, Steve Q said:

I can't say on a more modern, electrical controlled car so to speak. But when I had idling and stalling issues on a old Volvo 940 2.3 petrol a few years ago, when I disconnected the MAF it ran better which proved it was a faulty MAF. Which my diagnosis proved correct. 

Good enough for me. I’ll give it a go. 
 

many thanks. 

[Steve Q]

13 minutes ago, Coop748 said:

Good enough for me. I’ll give it a go. 
 

many thanks. 

You're welcome 🙂

[Coop748]

Just had the vehicle on a basic OBD tester.

Can anyone help decipher these values?

MAF - Tickover 9.11g/s 2500RPM 33.11g/s

MAP - Tickover 98Kpa 2500RPM 119Kpa

Are those values anywhere near where they should be?

Many thanks