A8 - hole in cylinder head(!). Advice sought
Discussion
Hello chaps,
I've got an Audi A8 3.0TDI. 2007 plate, 120K Miles.
I'm the 2nd owner having had the car for a little over 12 months. Car has always been serviced in the Audi dealer network.
I dropped it into my local, recommended Indy, for a major service.
I got a phone call 10 minutes later telling me that the car has a hole in the cylinder head.
Mechanic says he has never seen this before - and has no idea what would have caused it. Car runs fine - and there are no warning lights on the dash.
Next step seems to be stripping the engine to find out what's happened - this apparently is an engine out job and he isn't keen to do it and is suggesting I take it to Audi.
So some questions:
1) What the hell is likely to have caused a hole in the cylinder head in the first place? What is the potential bills for what they might find
2) How much of a job is it to remove the engine - I see this being very very expensive if I get Audi to do it?
This is bad timing - I got a £3.5K tax bill last week - and it very much looks like the Mrs has gone into labour a month ahead of schedule
Any advice/guidance/ideas gladly recieved.
Oh and if anyone can recommend a reputable Audi Indy around the Northants area that might be very helpful..
I've got an Audi A8 3.0TDI. 2007 plate, 120K Miles.
I'm the 2nd owner having had the car for a little over 12 months. Car has always been serviced in the Audi dealer network.
I dropped it into my local, recommended Indy, for a major service.
I got a phone call 10 minutes later telling me that the car has a hole in the cylinder head.
Mechanic says he has never seen this before - and has no idea what would have caused it. Car runs fine - and there are no warning lights on the dash.
Next step seems to be stripping the engine to find out what's happened - this apparently is an engine out job and he isn't keen to do it and is suggesting I take it to Audi.
So some questions:
1) What the hell is likely to have caused a hole in the cylinder head in the first place? What is the potential bills for what they might find
2) How much of a job is it to remove the engine - I see this being very very expensive if I get Audi to do it?
This is bad timing - I got a £3.5K tax bill last week - and it very much looks like the Mrs has gone into labour a month ahead of schedule
Any advice/guidance/ideas gladly recieved.
Oh and if anyone can recommend a reputable Audi Indy around the Northants area that might be very helpful..
I think you need to understand where the hole is and what it is affecting, as the engine runs fine it doesn't seem to be causing major problems.
Audi will charge you a fortune to investigate and probably not come to any useful conclusions unless it can be classed as a manufacturing defect.
Audi will charge you a fortune to investigate and probably not come to any useful conclusions unless it can be classed as a manufacturing defect.
Modern Diesels are a mystery to me - but apparently the hole is near the manifold.
I'm a bit stuck as to what to do to be honest. I imagine that it be seeing all sorts of fault codes if it was causing problems - but have no idea when the problem ocurred as it could have happened on the drive down to drop it off.
I really don't want to have to take it to Audi as it's going to be hugely expensive.
I'm a bit stuck as to what to do to be honest. I imagine that it be seeing all sorts of fault codes if it was causing problems - but have no idea when the problem ocurred as it could have happened on the drive down to drop it off.
I really don't want to have to take it to Audi as it's going to be hugely expensive.
Just spoken with my mechanic..
Hole near manifold - about the size of a fingernail.
Diagnositics plugged in - showing nothing untoward.
He reckons that it's probably a knackered exhaust value which has then caused a burn through.
He believes that they can repair the cylinder head - and that I'm looking at a bill of 2-2.5K for the total job - but they won't know more until they can get the engine out and stripped down.
Frankly as much as a routine sevice costing me 2.5K more than anticipated pisses me off I'll live with that. Audi would charge me £2k for a new cylinder head alone - and that's before they charge me 20 odd hours labour for the engine in and out at an extortionate rate plus whatever they find wrong with it...
Hole near manifold - about the size of a fingernail.
Diagnositics plugged in - showing nothing untoward.
He reckons that it's probably a knackered exhaust value which has then caused a burn through.
He believes that they can repair the cylinder head - and that I'm looking at a bill of 2-2.5K for the total job - but they won't know more until they can get the engine out and stripped down.
Frankly as much as a routine sevice costing me 2.5K more than anticipated pisses me off I'll live with that. Audi would charge me £2k for a new cylinder head alone - and that's before they charge me 20 odd hours labour for the engine in and out at an extortionate rate plus whatever they find wrong with it...
He is aiming to have the cylinder head repaired.
I'm being told that because the cam chain is at the rear of the engine it's an engine out job to diagnose the issue which has caused the hole in the cylinder head in the first place.
Engine out then back in is 20 hours labour according to him - at 55PH that's already a grand.
This guy comes recommended to me - and he seems to be honest and trying to limit the costs as far as possible.
I have no reason to disbelieve him - unless someone better informed on here can tell me that they don't need to take the engine out to take the head off and diagnose the problem.
I'm being told that because the cam chain is at the rear of the engine it's an engine out job to diagnose the issue which has caused the hole in the cylinder head in the first place.
Engine out then back in is 20 hours labour according to him - at 55PH that's already a grand.
This guy comes recommended to me - and he seems to be honest and trying to limit the costs as far as possible.
I have no reason to disbelieve him - unless someone better informed on here can tell me that they don't need to take the engine out to take the head off and diagnose the problem.
I would go and find another example and look at engine to confirm that yours definitely has this hole where others dont. Also pictures would help people provide a more informed opinion. If this is an exhaust 'burn through' is the hole black and sooty, if not then no exhaust gases are coming out through it so it may just be a badly cast cylinder head that is not faulty at all.
Personally with those estimated repairs costs and confirmed as faulty is it worth repairing, selling on maybe a better option especially if it is running fine.
Personally with those estimated repairs costs and confirmed as faulty is it worth repairing, selling on maybe a better option especially if it is running fine.
No comment on the diagnosis or the quality of audi cylinder heads (ahem) but I have recently had to replace the cylinder head of an A6 2.0tdi and it cost me about £700 for a 3rd party head and more for fitting and rebuilding. I wouldn't buy a reconditioned or repaired head personally. I have no doubt that the rebuilding and replacement part for a 3.0tdi v6 is substantially more....
You're in Northants, a bit far perhaps from my Indy in Medmenham near Henley but I really rate him...
You're in Northants, a bit far perhaps from my Indy in Medmenham near Henley but I really rate him...
Edited by humpy999 on Thursday 30th January 22:11
Just be certain he knows what he is doing before you go ahead.
There are machined holes in the head that vent combustion gasses if an injector leaks, engine makes a chuff chuff sound like a steam train. You get a tell tail black oily sooting residue at the hole.
I've had head off on A4 and A6's with 3.0TDI with the engine in the car. Cant say for sure if its possible on A8 but I would have thought so. The chains are at the back which is a problem but there are covers to take off to remove the gears and tensioners to lift off the heads.
Depending on where you live, your local Audi center will want £75-£130 per hour but they will know all this.
There are machined holes in the head that vent combustion gasses if an injector leaks, engine makes a chuff chuff sound like a steam train. You get a tell tail black oily sooting residue at the hole.
I've had head off on A4 and A6's with 3.0TDI with the engine in the car. Cant say for sure if its possible on A8 but I would have thought so. The chains are at the back which is a problem but there are covers to take off to remove the gears and tensioners to lift off the heads.
Depending on where you live, your local Audi center will want £75-£130 per hour but they will know all this.
Tame Technician said:
Just be certain he knows what he is doing before you go ahead.
There are machined holes in the head that vent combustion gasses if an injector leaks, engine makes a chuff chuff sound like a steam train. You get a tell tail black oily sooting residue at the hole.
Sorry forgot to update this.There are machined holes in the head that vent combustion gasses if an injector leaks, engine makes a chuff chuff sound like a steam train. You get a tell tail black oily sooting residue at the hole.
But yes, exactly as you describe - the mechanic identified exactly this due a knackered injector gasket which is getting replaced.
Apologies for bumping an old thread, but my 3.0 TDI Phaeton has just been diagnosed by the dealer with a similar "hole in the cylinder head" problem. Although I haven't seen the problem myself, from having spoken to the service technician, it sounds like the leak is coming from one of the small holes just above the exhaust ports in the picture below:
They're advising removal of the engine and replacement of the cylinder head but if that's the exhaust hole for the injector is this a fix that could be done with the engine in situ?
Many thanks!
They're advising removal of the engine and replacement of the cylinder head but if that's the exhaust hole for the injector is this a fix that could be done with the engine in situ?
Many thanks!
Edited by W8aMinute on Thursday 4th September 15:54
Sorry - I should have updated this.
As Tame Tech above suggest there is a blow by hole engineered into the cylinder head which is there to deal with any leaking injector units.
This, as it transpired was the issue with mine - an injector gasket had failed and it was leaking - there was a lot of sooty, scummy residue around the hole which made it look like it had been burned through.
My was dealt with by an Indy who removed and cleaned up the head and fitted a new injector gasket.
The engine still needed to come out - and it cost be a grand to have the whole lot done - but at Audi it would have been twice that in labour plus 2K for a new cylinder head.
As Tame Tech above suggest there is a blow by hole engineered into the cylinder head which is there to deal with any leaking injector units.
This, as it transpired was the issue with mine - an injector gasket had failed and it was leaking - there was a lot of sooty, scummy residue around the hole which made it look like it had been burned through.
My was dealt with by an Indy who removed and cleaned up the head and fitted a new injector gasket.
The engine still needed to come out - and it cost be a grand to have the whole lot done - but at Audi it would have been twice that in labour plus 2K for a new cylinder head.
Thanks for the update. So it's an engine-job either way? I suppose I'll let them yank the engine and then have a poke around. Naturally, I'd rather not replace the whole cylinder head if it can be avoided (or take the engine out for that matter!)
Edit: I'm no expect, but after ogling pictures of the injectors and cylinder head, the only seals appear to be a copper one at the tip of the injector and two rubber o-rings, all of which are accessible with the engine in the car. Am I missing something?
Edit: I'm no expect, but after ogling pictures of the injectors and cylinder head, the only seals appear to be a copper one at the tip of the injector and two rubber o-rings, all of which are accessible with the engine in the car. Am I missing something?
Edited by W8aMinute on Thursday 4th September 15:52
If its just gasses blowing past the injector and coming out the machined hole.......
It Justs need new injector sealing washer and nuts, or replacing the failed injector if one is damaged.
Engine stays in the car heads stay on. couple of hours work.
If there is another hole in the head, then yes its a big deal head off etc.
It Justs need new injector sealing washer and nuts, or replacing the failed injector if one is damaged.
Engine stays in the car heads stay on. couple of hours work.
If there is another hole in the head, then yes its a big deal head off etc.
The dealer technician said that there were oily carbon deposits coming out of two of the vent holes on the offside bank of the engine.
The dealer has been very decent and had offered to replace the cylinder head for £1,600 but I've asked them to refresh the washers & o-rings on those two injectors first to see if it cures the problem.
I had a number of the chocolate injectors replaced a few years ago and have asked them to check the service records to see if the injectors that were replaced correspond with the ones that appear to be causing problems at the moment...
Thanks for the advice Tame Tech. When the injectors are removed, should it be pretty obvious if it's the seals that have failed?
The dealer has been very decent and had offered to replace the cylinder head for £1,600 but I've asked them to refresh the washers & o-rings on those two injectors first to see if it cures the problem.
I had a number of the chocolate injectors replaced a few years ago and have asked them to check the service records to see if the injectors that were replaced correspond with the ones that appear to be causing problems at the moment...
Thanks for the advice Tame Tech. When the injectors are removed, should it be pretty obvious if it's the seals that have failed?
Hi guys I have similar issues , I am getting strong diesel fume smell entering the cab and you can smell burning diesel when you open the bonnet
I also see black gunk on the left side of the engine manifold (diesel coke)
Could this be leaking injectors on my Q7 sline
I also hear a chuffing noise on the same side
So I put a torch in the manifold area and I see little tiny squirts of diesel coming from the manifold area
I also see black gunk on the left side of the engine manifold (diesel coke)
Could this be leaking injectors on my Q7 sline
I also hear a chuffing noise on the same side
So I put a torch in the manifold area and I see little tiny squirts of diesel coming from the manifold area
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