2.0TDi Oil Pump / Balancer shaft problems - the definitive guide! Audi VW Skoda SEAT

[Gazzza]

THanks again for the help and quick reply.

OK so you are saying if they are just changing the hex, then you wouldn't need to do all cambelt change prep work, as they are not removing the module, which explains why they have told me no saving across the two jobs. I'll call and check but Im sure he said he was just changing the hex (and this mention of circuits, which I confess I didn't understand either).

Isn't the jist of this thread that the issue (with the gear driven hex key version) is the originally fitted hex key is only circa 77m and turns out is too short and therefore prone to the rounding poblem. So why woud simply replacing it with a longer 100mm not be an acceptable solution ?

Didn't vag solve the problem on the newer (post 2010 engines) by simpy usign the longer hex key ?

Sorry if these are idiotic questions!

 

[Mario]

Isn't the jist of this thread that the issue (with the gear driven hex key version) is the originally fitted hex key is only circa 77m and turns out is too short and therefore prone to the rounding poblem. So why woud simply replacing it with a longer 100mm not be an acceptable solution ?

Didn't vag solve the problem on the newer (post 2010 engines) by simpy usign the longer hex key ?

Sorry if these are idiotic questions!

Right, the problem is 2-fold. The original 77mm hex key is made of a softer material and the balance shaft is also made of a soft-ish material. The fault can occur in 2 ways, either the hex key rounds and you lose oil pressure or the hex recepticle in the balance shaft rounds and you lose oil pressure.

You also cannot fit a 100mm hex key into an unmodified balance shaft, it simply will not fit, the shaft has not been machined to accept a longer hex key. So if they are just replacing the hex it will be with a normal 77mm one.

VAG did indeed fix the issue with a 100mm hex key, but they made the keyway in the shaft deeper to accomodate the longer hex key and they made the hex key out of harder material.

If he is not removing the module and simply replacing the kex key it will be with a 77mm key which will likely result in the hex within the original shaft rounding off later on causing the same problem with no oil pressure. A 100mm hex key cannot and will not fit into an unmodified shaft, and you cannot replace the shafts without locking the engine at TDC....well technically you can, but that's also a bodge as you can never guarantee it is correctly timed up with the engine again when re-fitting unless the engine is at TDC and you use proper locking tools to keep the engine there and to line up the balance shaft module....all of which require access in and around the timing belt area.

 

[Gazzza]

Thanks Mario. Great info.

Spoke to my local specialist again. I misheard his colleague earlier, it was a bad line - Circlip not circuit :-D

Anyway this particular specialist will only work with audi parts. So it's the newer VAG 100m hex, trimmed to fit. The full 100mm length obviosuly won't fit, but he said there is space to accomodate more than the original 77mm part, though still leaving room for heat expansion etc. He said it was definately worth doing as the one's he's seen failed had rounded and it will eventually happen. He's done this fix on a few that have failed, but if it goes you have no warning and within seconds you can damage the engine. It's a specialist I've been using for a while so I do trust, but it seems like I'll only be getting some extra length over and above the 77mm not a full 100mm hardened replacement.

It's so damn annoying Audi wont even sell a replacement shaft and hex key as a supported fix. Their own warrantable fix is to replace the entire oil pump. Thousands. Only other option is to find another specialist who will work with third party parts.

 

[Mario]

Circlip makes much more sense! However their "fix" is a BODGE!! I would walk away! The KMB Parts Kit is a Genuine OEM Audi balance shaft which has been modified to accept the longer 100mm key and the keyway hardened, so I don't see why they won't use it.

Also, an OEM 100mm balance shaft will not fit into your balance shaft module, so even if Audi would sell you just the shaft, it would not work as the entire module was re-designed, but the biggest change people mention is the longer hex key used.

Personally I would get your "specialist" (I use that term loosely going by what I have heard) to use a KMB Kit or find someone who will. Fitting cut down hex key into the shaft will only mean that the hex key will not round...however the hex receptacle the key sits in CAN still round off, and probably will if you fit a harder hex key into the original, unmodified, balance shaft.

Cutting a new part to make it fit has "BODGE" written all over it, and at most will give you an extra 1-2 mm of length! Basically a waste of time and money.

Oh, and £550 for that is not worth it either, as they are doing half the job and realistically it could be done the way they describe in 3 hours or so...then the 100mm hex key is a £2.50 part, so £550 for that job is a rip off also!

Where are you located? If you are near the NE Scotland I am happy to help doing it DIY, or someone near you can maybe recommend someone they have used to fit a KMB Kit.

Oh, and doing it the proper way will require additional bolts, etc as all the bolts that hold the module to the engine and the subframe, etc are all torqued to yield (torque spec + angle) which means they stretch when fitted and should not be re-used, however some people do re-use them and simply torque them without the extra 90* or 180* turn, as they can risk snapping the bolt when doing the final angle part if it's not been renewed.

I can supply a list of all bolts / parts you need to replace inc the Audi part numbers if needed. Cost of bolts + genuine Audi sealant for the sump is approx £100....the sealant is £20 alone.

 

[Gazwould]

Wow , a 'trusted specialist' trims the 100mm key to get a few mm over the 77mm , wow !

A 77mm would be OK if the materials were hard enough and the keyway actually hexagonal , but to be 100% bullet proof , over engineer it !

77mm Polish style .

 

[Retroman]

The Polish picture (right) shows the hollow hex drive. Didn't VAG harden it and make it solid around 2007?

 

[Mario]

The Polish picture (right) shows the hollow hex drive. Didn't VAG harden it and make it solid around 2007?

I believe so, just as the 100mm key is solid and hardened, but all it did was make the balance shaft itself round off instead of the hex key...simply moving the point of failure to the next weak link in the chain. By the "specialist" recommending what they have said above, it will do the same and just move the failure point to the shaft instead of the hex key.

 

[Retroman]

Only ever seen evidence of worn hex drives online - pre and post 2007

 

[Mario]

If you go an read the monster (60 page I think) thread on here there are a couple of guys who have changed just the hex key and then later came back to say they have had the key way in the shaft round off. It is definitely less common, but it does happen, usually after fitting a hardened hex key to a normal 77mm shaft.

Seeing as the majority don't go down that route after the first failure they experience, it makes sense that you don't see it mentioned often.

 

[Gazzza]

Thanks again Mario, and others, for your help and info. Sadly I'm nowhere near NE Scotland.

To be fair he did say this wasn't really a true fix, more an adaptation of an Audi component (the official supported Audi fix being the entire pump replacement). I won't mention names but I've seen them recommended on Audi forums in the past. He didn't pull the wool over my eyes or anything, but also said from prior experience their policy was not to work with 3rd party products, only Audi components. He made the point that my existing hex has lasted 10 years 100k miles, so this fix should last a similar time by which time the car will be nearing end of life. I could ask again specifically about using that kit though as an overnengineered solution might give me more peace of mind. I've not had much love for this car alas with it's string of problems. Every year to 18 months theres seems to be a boost issue it rarely feels like it got full power and range, and I'd like to relax with the car a bit more.

I'm in the area of Woking, Guildford, Dorking, Leatherhead. I don't mind driving a bit so anywhere say in the circle of Epsom, Crawley, Horsham, Haslemere, Farnham/Farnborough, Brackell, Slough, Croydon. So SW London/NE Surrey. If anyone has had this specific replacement to the KMB part done in this area I'd be interested in reccomendations.

Cheers

 

[tut_gareth]

Thanks again Mario, and others, for your help and info. Sadly I'm nowhere near NE Scotland.

To be fair he did say this wasn't really a true fix, more an adaptation of an Audi component (the official supported Audi fix being the entire pump replacement). I won't mention names but I've seen them recommended on Audi forums in the past. He didn't pull the wool over my eyes or anything, but also said from prior experience their policy was not to work with 3rd party products, only Audi components. He made the point that my existing hex has lasted 10 years 100k miles, so this fix should last a similar time by which time the car will be nearing end of life. I could ask again specifically about using that kit though as an overnengineered solution might give me more peace of mind. I've not had much love for this car alas with it's string of problems. Every year to 18 months theres seems to be a boost issue it rarely feels like it got full power and range, and I'd like to relax with the car a bit more.

I'm in the area of Woking, Guildford, Dorking, Leatherhead. I don't mind driving a bit so anywhere say in the circle of Epsom, Crawley, Horsham, Haslemere, Farnham/Farnborough, Brackell, Slough, Croydon. So SW London/NE Surrey. If anyone has had this specific replacement to the KMB part done in this area I'd be interested in reccomendations.

Cheers

I junked my balance shaft setup at 107k in favour of an ALH oil pump set up. So no future issues. My hex key wasn't badly worn but the amount of play to the oil pump drive was! Your welcome to come have a look at the unit if you want... I'm near Woking.

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[Retroman]

Most people changing their systems seem to be doing so for the fear of the failure and not because of the failure itself.

 

[Gazwould]

Which is a very good idea as some damage occurs before failure as the oil pressure drops with partial failure through the slipping of the rounding key .

Turbo will suffer first .

The low oil pressure monertering is very poor .

 

[tut_gareth]

Most people changing their systems seem to be doing so for the fear of the failure and not because of the failure itself.

Because failure is likely to be a new engine due to oil starvation. And that's probably why many A4 2.0 tdis are being broken..
I junked mine as the I had the front end of the car off for timing belt and dmf/clutch replacement. Glad i did.

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[owais2k1]

Circlip makes much more sense! However their "fix" is a BODGE!! I would walk away! The KMB Parts Kit is a Genuine OEM Audi balance shaft which has been modified to accept the longer 100mm key and the keyway hardened, so I don't see why they won't use it.

Also, an OEM 100mm balance shaft will not fit into your balance shaft module, so even if Audi would sell you just the shaft, it would not work as the entire module was re-designed, but the biggest change people mention is the longer hex key used.

Personally I would get your "specialist" (I use that term loosely going by what I have heard) to use a KMB Kit or find someone who will. Fitting cut down hex key into the shaft will only mean that the hex key will not round...however the hex receptacle the key sits in CAN still round off, and probably will if you fit a harder hex key into the original, unmodified, balance shaft.

Cutting a new part to make it fit has "BODGE" written all over it, and at most will give you an extra 1-2 mm of length! Basically a waste of time and money.

Oh, and £550 for that is not worth it either, as they are doing half the job and realistically it could be done the way they describe in 3 hours or so...then the 100mm hex key is a £2.50 part, so £550 for that job is a rip off also!

Where are you located? If you are near the NE Scotland I am happy to help doing it DIY, or someone near you can maybe recommend someone they have used to fit a KMB Kit.

Oh, and doing it the proper way will require additional bolts, etc as all the bolts that hold the module to the engine and the subframe, etc are all torqued to yield (torque spec + angle) which means they stretch when fitted and should not be re-used, however some people do re-use them and simply torque them without the extra 90* or 180* turn, as they can risk snapping the bolt when doing the final angle part if it's not been renewed.

I can supply a list of all bolts / parts you need to replace inc the Audi part numbers if needed. Cost of bolts + genuine Audi sealant for the sump is approx £100....the sealant is £20 alone.

Hi,

I have an Audi A6 2006 BRE Engine. 88k mileage.

I am about to get the KMB kit changed in the oil pump. Timing belt will be done at the same time.

Is there a guide, how long will it take once the Oil sump is off.?

Can you provide the list of Parts you mentioned above.

Any help so I can give to the mechanic.

Thanks in advance guys.

 

[Mario]

Hi,

I have an Audi A6 2006 BRE Engine. 88k mileage.

I am about to get the KMB kit changed in the oil pump. Timing belt will be done at the same time.

Is there a guide, how long will it take once the Oil sump is off.?

Can you provide the list of Parts you mentioned above.

Any help so I can give to the mechanic.

Thanks in advance guys.

Going by ElsaWin and the official list of parts Audi say are single use, all of these should be replaced.....

N 90183802 Front Anti-Roll Bar Self locking nuts x4

N 90663002 Bolts for engine console mounts x4

N 90956803 Front sub-frame bolts x4

N 91048802 Vibration Damper Bolts x4

N 10601402 Balance shaft Module to engine bolts x5

N 91123401 Balance shaft Module to engine bolt x1

N 90977502 Balance shaft Module to engine bolt x1

N 91051201 Balance shaft Module to engine bolt x1

N 90951301 Oil Pick-up O-ring seal x1

N 0122942 Oil Pump Follower Key Retaining Clip x1

D 176404A2 - Silicon Sealant for Sump


It's a fair list, however I'm sure you can re-use the ARB nuts and possibly the vibration damper (crank pulley) bolts. Not so sure about re-using the rest. All in all you are looking at about £100 for all the bits mentioned above. I got all mine from Crewe Audi using the parts request form at the top of the page. Just copy and paste the list above and they will give you a price inc delivery.

Once the sump is off, it's only 1 hour or so to remove the balance shaft, open up, swap out and refit. The biggest pain is removing the sump itself anf is what involves 90% of the work.

I have LOADS of pictures and video footage I was planning to make into a guide, but I have not had time.

Also, I've attached a screenshot of the tightening sequence from ElsaWin for re-attaching the assembly to the block. I uses the same torques for the bolts that hold the 2-halves of the balance shaft together, but DO NOT add the extra 90* turn at the end because they are torqued to yield and might snap! Audi do not sell these bolts as replacements.

From what I remember, bolts 5 & 7 are lower torque because they are smaller diameter bolts. So use the torque rating that matches the bolts size (M8, M10, etc) that the 2 halves use, if that makes sense?

 

[Ryan M]

Hello guys, I've recently bought a '2005 170k A6 2.0L TDI - Engine Code (BLB)'. Unfortunately it's got no history of the oil pump ever being changed which has got me a little worried as why it hasn't failed yet or if it's been changed by a previous owner. After searching online around this forum I'm unsure what my current options are due to the vast amount of them, but I have stumbled across this on eBay and I'm wondering should I drop the sump and see if the pump has the stronger key, or should I just purchase the pump below and get it changed before the inevitable happens.

Link:
https://www.ebay.co.uk/itm/2005-2009-Audi-A4-2-0-TDI-Uprated-Gear-Driven-Oil-pump-Balance-Shaft/182870275401?_trkparms=aid=111001&algo=REC.SEED&ao=1&asc=20160908131621&meid=149d5390dcfe402f86ec2e01ea235ec1&pid=100678&rk=3&rkt=7&sd=281212284105&_trksid=p2481888.c100678.m3607&_trkparms=pageci%3Ac7e63596-c8dd-11e7-9539-74dbd1806572%7Cparentrq%3Ab835c4a515f0a86676be680cfffe3479%7Ciid%3A1

 

[Sturat]

If it's a BLB it would have had the chain drive oil pump originally so you definitely need to take a look by dropping the subframe and removing the sump and replacing it.
If you stick an inspection camera through the oil drainage hole it will show you whether the chain drive has been replaced previously with gears but not whether it's had the much needed updated hex shaft.

 

[Gazzza]

Most people changing their systems seem to be doing so for the fear of the failure and not because of the failure itself.

Because failure is likely to be a new engine due to oil starvation. And that's probably why many A4 2.0 tdis are being broken..
I junked mine as the I had the front end of the car off for timing belt and dmf/clutch replacement. Glad i did.

OK so I took the plunge, after finding another local specialist who was happy to fit the KMB part. Glad I did too.
Gareth - thanks for the offer of letting me look at your alternative setup, but I decided to stick with the pump and swap out the balance shaft instead.

Graham at KMB parts couldn't have been more helpful when I enquired on the replacement shaft itself, nor could Dave at VW Audi Specailist in Leatherhead who swapped it for me. Absolute pleasure to deal with, I'm very happy.

Anyway here are photo's of the old balance shaft and key. So this is from my 57 plate, BRD engine. One of the last B7's before they moved to the B8. 108k miles. The key is the 77mm one and is hollow. The rouding is visible on the zoomed out photo even before I took close ups. It was just waiting to fail by the looks of it ! I can't help but feel the engine has just dodged a potential bullet! Very relieved I took the plunge to swap.

Thanks all who took the time posting on this issue and for responding to my questions. Really appreciatted.

Cheers

G

 

[tut_gareth]

Crumbs that's a lot more rounded than mine was for similar mileage. How worn was the oil pump keyway?

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[Gazzza]

I didn't see it and the mechanic didn't comment on it, so I'm assuming the pump slot was fine.
I'm guessing as this is one of the original hollow shorter softer keys that almost all the wear is on the key.

 

[owais2k1]

Going by ElsaWin and the official list of parts Audi say are single use, all of these should be replaced.....

N 90183802 Front Anti-Roll Bar Self locking nuts x4

N 90663002 Bolts for engine console mounts x4

N 90956803 Front sub-frame bolts x4

N 91048802 Vibration Damper Bolts x4

N 10601402 Balance shaft Module to engine bolts x5

N 91123401 Balance shaft Module to engine bolt x1

N 90977502 Balance shaft Module to engine bolt x1

N 91051201 Balance shaft Module to engine bolt x1

N 90951301 Oil Pick-up O-ring seal x1

N 0122942 Oil Pump Follower Key Retaining Clip x1

D 176404A2 - Silicon Sealant for Sump


It's a fair list, however I'm sure you can re-use the ARB nuts and possibly the vibration damper (crank pulley) bolts. Not so sure about re-using the rest. All in all you are looking at about £100 for all the bits mentioned above. I got all mine from Crewe Audi using the parts request form at the top of the page. Just copy and paste the list above and they will give you a price inc delivery.

Once the sump is off, it's only 1 hour or so to remove the balance shaft, open up, swap out and refit. The biggest pain is removing the sump itself anf is what involves 90% of the work.

I have LOADS of pictures and video footage I was planning to make into a guide, but I have not had time.

Also, I've attached a screenshot of the tightening sequence from ElsaWin for re-attaching the assembly to the block. I uses the same torques for the bolts that hold the 2-halves of the balance shaft together, but DO NOT add the extra 90* turn at the end because they are torqued to yield and might snap! Audi do not sell these bolts as replacements.

From what I remember, bolts 5 & 7 are lower torque because they are smaller diameter bolts. So use the torque rating that matches the bolts size (M8, M10, etc) that the 2 halves use, if that makes sense?

View attachment 141127

Thanks for your help Mario.

I'll be passing this on to the Garage. I would rather they have more info to make sure it goes through smoothly.

Owais Hassan.

 

[Robertkent]

Hi, I have had 2006 a3 8p1 with engine code BKD for a year and done cylinder head, flywheel, clutch, and so on and i feel like this is some sort of problem that is gonna come up with this car but cannot find any stories about BKD and this issue. Do i have to take it open again at take a look at this balancer shaft?

 

[Ryan M]

Hi, I have had 2006 a3 8p1 with engine code BKD for a year and done cylinder head, flywheel, clutch, and so on and i feel like this is some sort of problem that is gonna come up with this car but cannot find any stories about BKD and this issue. Do i have to take it open again at take a look at this balancer shaft?

No, you don't need to worry, the 'BKD' engine did not get a balance shaft unit and the oil pump is driven in the same manner as the 1.9 PD engines with a chain and a tensioner and no balance shaft unit. The chain tensioner on the PD engines (your 'BKD') should last around 300k before needing changed if effected.

The reason the 'posher' 2.0 engines (A6, Passat) fail is because of the whole balance shaft design to reduce vibrations affecting reliability (because of a design flaw with the hex key rounding or the hex key shaft rounding which stops the oil pump being driven) and a hefty bill if not turned off when the oil pressure light shows.

If my oil pressure light does come on I'll probably switch to the 'BKD' engine or do a balance shaft delete which then switches the drive to be the same as the 'BKD' (pump driven by chain, no balance shafts).

Hope this clears things up Robert!

 

[andrei.dinu1985]

Why chain drive when you have gear drive mode that you can choose and you forget of any kind of problem. I changed on gear drive pump and the engine sounds more quiet and is more safe and reliable , with a cost of 600 euro, items plus garage service. See pictures for reference.

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[Rdonaghy123]

Can anyone tell me if my Jan 2010 CAGA 2.0tdi engine will have the 77mm?

I have a whine coming from the engine when I rev it which may just be turbo whine but I am concerned it could be something to do with this as the car has done 127k.

Any info appreciated

 

[Mario]

Can anyone tell me if my Jan 2010 CAGA 2.0tdi engine will have the 77mm?

Yes it does have the 77mm hex shaft.

 

[Gazwould]

It could have either 77mm or 100mm .

 

[Rdonaghy123]

Any way to tell for sure?

What are early symptoms of failure?

 

[Gazwould]

Take the sump off and withdraw the key.

 

[Mario]

It could have either 77mm or 100mm .

A Jan 2010 car wont have a 100mm hex shaft. Audi only started to put them into engines built from Feb 2010 onwards. A Jan 2010 registered car likely has a Nov / Dec 2009 engine in it, if not older.

 

[Rdonaghy123]

So is it a case of change it all asap?

I have a constant low pitch whine at idle which really could be anything, and a slight whine on revving.

 

[Mario]

At that milage I would change it, regardless of the whine (could be a million things), for peace of mind I would just change the balance shaft / hex shaft.

 

[Gazwould]

A Jan 2010 car wont have a 100mm hex shaft. Audi only started to put them into engines built from Feb 2010 onwards. A Jan 2010 registered car likely has a Nov / Dec 2009 engine in it, if not older.

Maybe...

OEM 100mm came out of a 2008 58 plate Passat with a common rail CBAB so the bloke wasted hundreds and fitting a 100mm KMB kit just before Christmas .

 

[Rdonaghy123]

What is the approximate cost of parts of you are to do the work yourself?

 

[Rdonaghy123]

According to oemepc.com CAGA could have either depending on manufacturing date, pre and post 19.10.2009

 

[leerees]

Lot of misinformation here. My 57 plate 2.0 170bhp failed, engine code BRD. Oil pressure failure, engine written off. Friends 2.0 was the same spec but BKD engine code, same thing happened to him. All Audi cars with a 2.0TDI engine have this problem and there is no way to tell if you've won the hex key lottery.

Audi are unable to give you a straight answer on the effected engines, they simply don't know. These cars are too old now and because of their age are no longer good value for money because of the amount you are going to have to spend correcting this issue. Save yourself the headache, even if you get a stronger hex key machined, it still can fail.

If you really want one of these b7 cars, then get the 115bhp 1.9tdi avant and don't even think about trying to remap it ;-)

 

[Retroman]

Interesting snippets coming in, was this "77mm balance shaft issue" restricted to pre-common rails 2.0 TDIs?

 

[Rdonaghy123]

Just to update this, I have contacted Audi and using my VIN to check they are confident it has the 100mm hex key fitted as it is manufactured on or after 10/09. So if I get an opportunity I will check but for now puts the mind at rest slightly

 

[tesh22]

Hi All,

If I want remove the Hex key to just inspect for now, do I still need to lock the engine into TDC.

Can i just drop the sump, first inspect if my key is hollow or solid, then remove circlip and slide it out with a magnet?

While im at it ill fit a new oil pickup pipe an clean out sump etc but generally concerned and want to inspect my key.

Thanks