S8 d3 v10 2007 engine torque settings

[Lee S]

Originally Posted by Mechcanico Lee

Respect to you for taking a big job on like that ....

My thoughts precisely... Well done !!

[Borys]

Missfire on those engine commonly is caused by carbon deposit build up in manifold. Having all apart get the manifold properly clean, check flaps for damage ... sorted
Decoke service is provided for all fsi engines by some specialists

[Mechcanico Lee]

Originally Posted by Borys

Missfire on those engine commonly is caused by carbon deposit build up in manifold. Having all apart get the manifold properly clean, check flaps for damage ... sorted
Decoke service is provided for all fsi engines by some specialists

Says he already done manifold decoke

[Borys]

Sorry missed that

[audis8tui]

Originally Posted by Mechcanico Lee

Pistonbroke .....yeah been there hehe

Interesting one this , if it's not a bent rod or it's not running close to the crank counter weight in any way , my next best surmise would be an over revving from cold , if the cars been stolen and in a chase this could be likely and yes it could of been a manufacturing defect and it only showed its face on the one piston .....it's hard to say , we could guess at a lot of things ..

You say it misses from cold , and the codes to do with low fuel pressure on that bank ..... would you say it's like one cylinder down or more or a general unevenness to it .

Has anyone had a Diesel engine run away with its self due to say a turbo failure or sump overffull of oil ..... I've had it once on a td6 Range Rover .... it's pretty scary ...... Billowing smoke and screaming it's nuts off till it throws a rod out , makes a reet mess ......... where am I going with this .......

So in some cases with a major over Rev the high pressure diesel pump breaks up ,the case hardening comes off the rotor and metal debris is scattered around the system .....where does the metal end up ....... yes ,in the injectors , so you end up with low pressure codes due to the back spills dumping it out .... high pressure fuel systems will not tolerate metal debris what so ever , the fuel system is as good as finished , contamination in pump , injectors , fuel rails , swirl chamber in tank , metal debris all in bottom of tank due to fuel returning all the debris back there .

Could this be the reason our v10 is giving codes for one bank for low fuel pressure , if a diesel pump breaks up and that is lubricated with oil , I would say for sure a high pressure petrol pump will break up .
Perhaps it's still able to deliver fuel but not up to spec , perhaps after the car has run for 5 mins or so the cylinder balancing and contribution is ramping the pressure and duration on that bank to get it to contribute to get engine smoothness.

On the bank that has low pressure.....the high pressure pump does it have a return pipe that has a banjo bolt with a basket filter in the banjo , or any return line banjo bolts for that matter , take them out and look for metal debris .

If you need the injectors testing I have a man .....he is Martin Wainwright from Wainwright Bros. look him up on YouTube .... proper professional and will inspect the nozzles and pintles under a microscope to look for metal particles

Lots of theory's and maybes , but to do all the work you already have done there , you have got to get it checked out ..... massive waste to put it all back and it not be right .

Respect to you for taking a big job on like that , most garages just don't want this type of work ....just to long winded and if one small thing is over looked you would be pulling it all back out again .

Lee

Well gents the new piston arrived, fitted and put all back in and its exactly the same.
I have today removed the engine and striped it down again, I have removed all the pistons on bank 6 to 10 and found to my horror cylinder bore to number 7 is not round. It looks like the piston has been going up and down un true.
All that work on piston number 8 made no difference at all.
My question now is I am told these blocks cannot be bored out as there is 6mm between the cylinder walls and the dealers tell me they don't supply oversized pistons.
Am I looking at scrapping the engine or even the whole car as a replacement block is way over my budget.
Has anyone had this issue before or even heard of it.
I can only assume that the water cooling has been interrupted and the cylinder wall has almost warped.
With just a piston ring sliding square down the cylinder wall there is a gap of 20 thou where the wall is warped.
Help

[tc4332]

Oh Bugger, enough to make your eyes water.
I feel for you.
Wishing you the best of luck with it from here on, hopefully it will come right. But an off round cylinder, wow

[Mechcanico Lee]

Wow !! did you check that the all the pistons come up to top dead and have clearance between crank weights and piston skirt .

The broken piston was cylinder 8 ? the cylinder out of round is number 7 , so 7 and 8 are on the same bank and next to one another ?
Is number 8 bore out of round aswell

Bad news man , can you see why garages don't want this type of work ..... one missed thing and it all has to come back out .

Any ' breaking cars ' with a full engine s for sale ?

[audis8tui]

Originally Posted by tc4332

Oh Bugger, enough to make your eyes water.
I feel for you.
Wishing you the best of luck with it from here on, hopefully it will come right. But an off round cylinder, wow

Well its Friday and a few bottles of Stells is better than a little cry in a dark corner.
I think a replacement engine is the way forward

[Delboy]

I noticed a s8 engine for sale on gumtree the other day

[audis8tui]

Originally Posted by Mechcanico Lee

Wow !! did you check that the all the pistons come up to top dead and have clearance between crank weights and piston skirt .

The broken piston was cylinder 8 ? the cylinder out of round is number 7 , so 7 and 8 are on the same bank and next to one another ?
Is number 8 bore out of round aswell

Bad news man , can you see why garages don't want this type of work ..... one missed thing and it all has to come back out .

Any ' breaking cars ' with a full engine s for sale ?

Yes I checked and all pistons have a full clear cycle, all come to the top at the same level.
Number 8 is next to 7 and is perfectly round
Its almost as if the damaged piston in 8 has been swapped from 7 as the damage to cylinder and piston match but this engine has never been out. I will tidy the garage today and have a fresh start