2005 A6 3.2l FSI - Belt tensioner changed now running lumpy.

[Bertros]

As per title. Changed the left bank tensioner (hydronic piston had shot) sounded horrendous, but not lumpy.New one went in and went back together "too well" started her up and it's lumpy as hell but no hitting noises! Just like a bank is not firing.

so next steps 1) vag com for misfire / coil pack check
2) compression check
3) re check timing / re time (if above holds no issues)

I am stuck if none of the above finds anything. Any other ideas welcome. Will report back

cheers

[Crasher]

Do you mean chain tensioner? AUK engine? Did you use the correct locking tools and set the sprocket/chain pre-load as per the manual?

[Bertros]

Hi Crasher,

Yes Chain not Belt - I will edit subject thanks!

I used the correct Tools, tensioned up to 65lbs and then added another 90deg turn.

I have a sick feeling re the pre-load you talk about, I do not suppose you can forward the Manuel / instructions so I can see what I missed ?

If I need to pop the valves I do not want to go making the same mistake.

Many thanks in advance

Robert

[Crasher]

Email me and I will send it to you. As you only have four posts I have send you a PM with my email.

[54A4Avant]

How do you know if your engine needs cam chain tensioner replacements? Is a rattle sound on startup (3.2 FSI) sufficient reason to suspect a problem, or is it a much more obvious noise?

[Crasher]

It is an experience based judgement and you can get the best feel for what the condition is when starting after an oil change, if the mechanic cringes, ducks or runs for cover, you know the chains are getting a tad sloppy.

[54A4Avant]

Thanks. Soon going to do a DIY oil change so the only cringing will be my own, although I suppose if the diagnosis is that I need to get shot of car ASAP perhaps I should pay a dealer for a stamp in the book. Plan was to keep the car 5+ years and service it myself, thinking that at 15 years of age any loss of value due to DIY servicing is minimal and offset by the money saved.

Maybe I should record an audio sample and post it up as others have done. I've read that with VCDS the measuring block 93 values can give an indication of the state of the chain and that if they're below 8 degrees per bank then it's all good. Will check that out at next opportunity.

[Crasher]

Remember that EU4> petrol engined cars are suddenly going to become very sought after and consequently in very short supply in the next year or so when people wake up to the FACT that dirty diesel is going to be hammered, Nottingham, Sheffield, Leeds and three other counties are introducing punitive non EU6 diesel/ non EU4 petrol emissions zones from 2020 and Nottingham has just moved theirs forward to 2019, the cameras are being installed on the A610 Nuthall roundabout at the moment.

[54A4Avant]

Interesting stuff. I haven't been following the debate around low emissions zones but for sure it's going to have an impact on used values. Imagine all those commuters suddenly dumping their diesels, prices will be rock bottom.

Can you expand on your comment about judging condition of timing chain tension on first startup after an oil change? I guess all the oil will have drained from the tensioner's piston so the chain will be at its slackest, so the rattle will tell you how stretched the chain might be?

[Crasher]

A jurno in Autocar was speculating that the values of non compliant cars was going to be virtually nil, even late 2014 big expensive cars if they are not EU6 diesel, their values will be destroyed when people wake up to what is coming.

The tensioning system drains so the chains go slack, the noises they make can be so bad I feel the blood drain from my face in horror.