UNSUB2K

2000 A8

codes: p1340 p0300 p0301 p0302 p0303 p0304

symptoms: rattling for a second aruond 1000rpm,
mil flashes on deceleration and will go off after about 20 seconds or when i accelerate.

I've replaced camshaft sensor and ordered a crankshaft sensor. I've searched online for info on flashing mil, misfires, during deceleration and found little. any ideas.

silverd2

Could be a valve timing problem on bank #1 (ONE possibility). Although chain rattle on cold start up is not unusual with a 40V engine, due to variable chain tensioner design...it might point to a problem there(?). If the chain tensioner pad on that side is broken (gone?) which is common failure at higher mileage, the chain could have jumped time.
To be sure, you'd first have to check proper belt timing (TDC on crank pulley mark) matching with cam belt pulleys set exactly at cylinder #5 (holes on pulleys at exact proper point).

Belt jumps are possible, but rare, so....

If all is well with the belt, under the valve cover the marks on the cams have to line up properly or timing has jumped...which could easily cause misfires on that side.

Just one theory...links have a similar problem, when chain pad broke complete:

https://www.audiworld.com/forums/sho....php?t=2757525

http://forums.quattroworld.com/a8/msgs/49862.phtml

Pchelka01

i had the same exact problem beginning of this year, silverd2 sent you a few links, that is exactly what ended up happening to me,
all four of the cilinders of one bank were misfiring so i rechecked the timing belt line-up (as i have recently changed it and thought that might be the problem)
but when i opened the valve cover i found that the plastic piece that the camshaft timing chain runs along was broken,

if its not that, its def. in the camshaft area.

sonata54

Had the same problem last year, my timing chain tensioner snapped and the chain became loose, is the rattling coming from the right side of the engine near the front? thats where that chain is located and would cause the noise

silverd2

On his 40V "AKB" motor (facelift D2 A8/S8), bank #1 tensioner and chain are at the rear of the engine (passengers side, cylinders 1-4)...and on the front of the engine on bank #2 (driver's side, cylinders 5-8).

nicaudi

Silverd or others - how did you eventually get this fixed?
did you have to pull the engine and then work on the tensioners?
(and chains etc)

I have a 4.2 (02 A8)
I just threw a P1340, (also P0300) and am wondering if there is some sequence to check to see if I can get this fixed w/o pulling the engine, and then doing the entire (and very expensive) timing chain fix - is there some sequence of things to try to fix first first?

thanks,

JoePGT5S

Despite what the Bentley manual says, it's possible to change the bank 1 tensioner/chain without removing the engine.

silverd2

???
There is no mention in Bentley (or anywhere I've seen) of pulling the engine to change anything in a head...either side...only removing the head itself, and that can be done without pulling the engine, too...it's been done.

Bentley (and Audi dealers) do pull the timing belt and both cams to change the tensioner (cam adjuster)....same on both banks.
I changed bank #1 adjuster (passenger's side) without even detensioning the belt or removing the exhaust cam...tight, but very doable >>

quattroworld.com Forums: Replacing cam chain tensioner and/or pads on bank #1 of 40V motor (shorter cut)...

^^ Please read EVERY word of this before attempting ^^

Bank #2 "should" be more difficult because of the placement of the belt sprocket in relation to the adjuster (opposite end from bank #1) and I've been told, by someone who's done it, that the belt and both cams MUST come out...I'll take their word for it, until I attempt it in the coming months...I have a new adjuster on the shelf waiting for that side...I'll let everyone know if the same shortcuts can be taken on that side...we'll see.

CAUTION: I did not do any of this work without the Bentley manual (as always)...I'm not a "complete" reckless idiot. There are too many steps in Bentley for removal and replacement which MUST be strickly adhered to. I did not (and will not) list all of these in that link. I only take short cuts when I realize that they are NOT at all needed for success.

Cheers

nicaudi

Thanks, this is great info, i will try to source the parts from Blau, and work with my mechanic- i dont have the guts to try this myself - especially as i dont have a covered garage at this time, thanks!

silverd2

What's a "covered garage"? ...one of those car houses I hear about?