2,5 tdi AKE running rough when warm.

[Crasher]

If everything is mechanical perfect the only thing it points to is the pump. I have had a lot of bad experiences with rebuilt VP44's and now I will only fit a genuine Bosch exchange unit as the VAG exchange unit is just too expensive.

I agree with Chris (adams24) that the head gasket issue is odd but due to people messing around I always check the piston height against the spec to make sure the gasket is correct in the first place, you never know!

[ametlib]

Mechanics/ compression/ oil pressure is all fine. Will do the Pump first, then the left head gasket and if that didn't do it I will sell it as a boat anchor .
Glad you didn't mention the ECU, thanks for answering!

[Crasher]

I can see the ECU causing the loss of power issue but not a rough idle, well not the main ECU anyway, the one in the pump however...

[adamss24]

Yes everything is done " by the book " Have changed the dynamic timing from -2 to +0,5 degrees as this seems to take some of the "bark" out of the old lady.
Cam timing done with camplates, crank- and pump pins, checked twice after cam-replacement, is ok.

I still think there's something odd with your engine having different head gaskets, before throwing any more money at it i would just wipe the heads off and check the piston protrusion on the one with the thickest head gasket... I would ALWAYS fit thicker head gaskets as it's better to decrease CR than risk piston to valve contact. Out of curiosity, how long since you pulled the head ?
VP44 either work or don't ! If the pump cannot get enough advance it would complain and trigger a fault code, i suggest u look at the mechanical issues first ! Don't worry about the main ECU, only time i found a faulty one is when looking at a chap's from N. London allroad which was a Non Starter, taking the ECU cover to check suses and power supply relays revealed this !




Still not clued up of what was that for, some sort of immo delete i suppose as the EDC15 is flashable trough OBD with a £15 Galetto lead... Car belonged to a forum member from N. London, i got a pair of heads rebuilt for him but never got the chance to fix his engine due to work commitments , he had them fitted by someone else and never got the car running again. Personally i am glad i did not took on the job as that car proved to be a load of trouble ! Old fella and his mechanic drained the gearbox oil instead of the engine oil then burned the starter trying to start the car with engine full of over 10L of oil, the allroad sold on ebay a couple of weeks ago still as "spares or repair" after spending twice what was worth !

[Crasher]

When will old school mechanics "get it" that modern cars cannot be "fixed up" like a 72 Tina!

[adamss24]

When will old school mechanics "get it" that modern cars cannot be "fixed up" like a 72 Tina!

I know exactly what you mean, bought a b6 avant tdi quattro 2 weeks ago, was advertised as spares or repair off ebay, got it for a decent price.
Got the car home, plugged my laptop in, checked voltage to the pump- ok, checked pump belt- ok, checked cambelt- ok, engine cranked well with plenty compression- code stored in the ECU pointing to pump EDC failure so i was just about to strip the front off to check timing when i remembered to check if the tank was filled with diesel or not, guess what the tank smelled off ? Finest BP unleaded !
I remembered the advert said AA/RAC old skool mechanic came and checked all fluids and deemed the car as beyond economical repair ! Quite a tidy motor as well...drained 40L of diesel/petrol mix and filled with diesel + a few squirts of 2 stroke oil and it fired first turn of the key ! Gets really good mileage as well after being run on petrol mixture as well...

[ametlib]

adamss,
Been around 4 months since I rebuild the heads.
I bought this car (cheap) , knowing it had a blown turbo and bad camshafts, also suspect MAF was out( was right)

Driwing it home, it was so damn noisy so I woudn't possibly have noticed this little bark. So I have absolutely no
idea if this issue is new or old.
Its not like a mechanical noise, more like diesel burning, fast,
Can easy take away this noise by giving it some throttle or let of the pedal.
Agree with you about the I.P.
The ones I have seen faulty, have all been STONE dead.
But what ELSE could it be ? The different in thickness of theese headgaskets its only 0.05mm. If I have a too thin gasket
,simple mathematics shows that it only changes compression ratio from 18,5/1 to 18,62/1 !?

[ametlib]

Forgot to tell that changing the injectors made it soo much better, but still some bark left.

BTW. Nice ECU pic, great solution to drain out water!

[adamss24]

Were the cams good quality ones ? Reason i ask is i've rebuilt a mate's a4 tdi a few years ago, he bought some cheap cams from germany and the lifters and rockers were stamped with e in a circle similar to @, the lifters were rubbish and made the engine sound like valves were kissing the pistons. Took the heads off 2 or 3 times till i realized there was issues. The exhaust valves were indeed touching the pistons and i used 3 holes head gaskets after that- previously used replacement 2 hole HG- then the problem went away ! Did not live long that engine though, it bent rods as some idiot drilled holes into the breather/ oil separator instead of fitting a new one ! I still have the engine in my shed somewhere but i used the heads on different engines/projects. I would also check the cams again, when under the oil pressure the lifters can move the exhaust cam one tooth on the cog so the valves kiss the pistons- you don't hear it at iddle but it's there as you increase the revs to 1500-2000 rpm's. Usually i take the exhaust cam and turn one notch then noise goes- no need to disturb the cambelt! Hope it's a cheap fix as it's seems like you spend enough money and time troubleshooting it, you have any hair left ?

[ametlib]

Were the cams good quality ones ? Reason i ask is i've rebuilt a mate's a4 tdi a few years ago, he bought some cheap cams from germany and the lifters and rockers were stamped with e in a circle similar to @, the lifters were rubbish and made the engine sound like valves were kissing the pistons. Took the heads off 2 or 3 times till i realized there was issues. The exhaust valves were indeed touching the pistons and i used 3 holes head gaskets after that- previously used replacement 2 hole HG- then the problem went away ! Did not live long that engine though, it bent rods as some idiot drilled holes into the breather/ oil separator instead of fitting a new one ! I still have the engine in my shed somewhere but i used the heads on different engines/projects. I would also check the cams again, when under the oil pressure the lifters can move the exhaust cam one tooth on the cog so the valves kiss the pistons- you don't hear it at iddle but it's there as you increase the revs to 1500-2000 rpm's. Usually i take the exhaust cam and turn one notch then noise goes- no need to disturb the cambelt! Hope it's a cheap fix as it's seems like you spend enough money and time troubleshooting it, you have any hair left ?

Great post! LOVE it.
Have been there. Couple of years ago, another A6. Bought a nice camshaft kit from ebay Germany.
Replaced the cams, bleed the pump, started and sounded great.
Test drive, got around 100m and then R-R-R-R-R, another 100 and the noise doubled!
Long story short, just by luck I noticed something odd about the rockers. Looking at them from the valve end, the contact surface at the cam had a total different angel
than the contact surface at the valve brick.
Replaced them with INA rockers, all fine.( The ad. stated " superior quality", compared to wooden cams, I guess)
Since then I have avoided quality products from the great country of China