Low Oil Pressure warning - Intermittent

[tmoram86]

Hi all, new to the forum although I have been lurking/browsing for a while. I've recently purchased a 2007 Audi A6 avant 2.0 TDI S-Line (BRE) auto.

I'm getting an intermittent low oil pressure warning alarm. I've read several threads about oil pressure, oil pump, balance shafts etc etc. The reason I've started a new thread here is that my car has had nearly all suggested parts checked, cleaned or replaced under warranty, and the garage are scratching their heads with it now! Looking for some advice or things that I can ask my garage to check. Bear in mind; this car is still under warranty, so anything you suggest to do won't be costing me :o

This is the list of work that the car has had done, some was done just before I purchased the car, and the rest has been done in the last couple of weeks.... All info taken from invoice/service sheets from the past few months



Full service
New front tyres
New rear pads and discs
Replaced front velocity joints
Replace rocker cover gasket
Replaced faulty mass flywheel
Cambelt kit and water pump
Replaced cam seals
Investigate engine knock; Replaced number 1 -4 injectors (Edit: Spoke with garage and I think they only replaced 1 injector - bad English on the service sheet!!)
New fuel filter
Oil & filter change
Replaced lambda sensor
Investigate oil pressure fault; Removed cambelt and oil pump
Removed oil sump, inspect and clean sump and pickup strainer (mechanic advised that he cleaned out some oil related pipes/hoses too)
Fit new oil pump and hex shafts
Rebuild engine and tested
Replaced oil pressure switch
Changed oil and filter
Replace/top up fluids
Re-Gas air con, found ac pump faulty
Supply and fit new air con pump


As you can imagine, after such an extensive list of work, I was fairly confident that all would be good.... But after a 40min drive and I got the oil pressure warning come on three times. I then parked up, came back to the car an hour later and drove it home - no warning lights. I then drove the car for well over an hour & half and the warning light popped up only once!??!

Other things to note (*might be related*?)... Sometimes (only sometimes) the revs bounce when idling and the engine feels very shaky. On the rev counter the needle bounces between 1 and the marker just below 1. It's as if I'm very gently tapping the accelerator in neutral. The other thing to note is that a friend was following me driving it recently and said "it stinks".... not too helpful, but my in-laws were in their camper behind him and they said that the smell reached their cab - two cars back! He noticed that at the bottom of a long downhill when I put my foot down to go back up the other side that it smoked a bit and smelled quite strong, couldn't describe the smell but the smoke was whiteish with a blue tinge... I've tried looking out for it in the mirrors but can't say I've noticed it, I've definitely noticed a strong smell around the back though.

I'm taking it back to the garage today who are very apologetic and said they'll be taking me under their wing with this, assuring me that they'll get to the bottom of it. As I said, it's under warranty so not costing me anything yet. I'm after some information/ideas/suggestions of things to tell the mechanic to check, please fire away! My garage is next door to a diesel specialist, so maybe they could assist?

The car has had so much work done on it, that I'm sure if I can get this oil issue sorted I'd have several years of happy motoring! If I can get it sorted... It's been in the garage for longer than I've owned it now :crying:, been with them so long that I'm thinking of asking for a new MOT once it's finished.

Any help greatly appreciated.

[Gazwould]

Odd one , but the oil pump drive really needs the re-enginnered modification to eliminate the well known issue.

Oil Pumps - KMB Parts Direct (http://www.kmbpartsdirect.co.uk/oil_pumps.html#kit9)

[tmoram86]

Hello, thanks for the response. The well know issue being the balancer shaft issue, yes? They've replaced the oil pump and "hex shafts" already, he said he inspected the balancer shaft assembly and it looks ok... Thought that might protect me from balancer shaft / oil pump failure for a while at least! Doubt that I'd get them to purchase and install what you've linked to under warranty, although something to bear in mind later - thanks.

[Gazwould]

Sound like a bunch of numpties to me .

The keyway in the balancer shaft that receives the 77mm hex key is not hexagonal !!

Furthermore it only has 15mm contact length which adds up to a slack arrangement and not an engineering fit .

Oem CR 100mm increases the contact length by more than double to 35mm .

An aftermarket modified remanufactured 100mm balancer shaft kit to 38-40mm with the balancer shaft keyway actually being hexagonal and 10 times harder chrome vanadium .

[tmoram86]

Just as I was starting to trust them! :\ So you're saying that Kit 9 in that link you sent me; "Kit 9 – KMB9– Audi / VW 2.0tdi Oil Pump Balance Shaft - Gear Driven" - is the right part and should protect me from the known problems related to oil pump/balancer shaft.

I'll send the link to the garage and see what they say, but is that likely to affect the Oil Pressure warning that I keep getting?

[nevo]

Have you had the oil pressure tested mechanically,and don't jump down my throat but are you sure it's not the oil level alarm.

[tmoram86]

Hello.. yes the oil pressure was tested and he put on the service sheet "found oil pressure drops when engine revving". He then replaced the oil pump etc... however, upon talking to him this morning he didn't test the oil pressure again afterwards...Seems like the logical thing to do right?
Definitely oil pressure alarm, not oil level!

[nevo]

Ok just a thought about the level,you wouldn't be the first to get them mixed up,anyway first thing first insist on a oil pressure test that will confirm if its low or your new pressure switch,have they actually changed the balance shaft itself or just the hex drive,if its worn inside then its not going to drive the pump.

[Rob69]

Reading through this it looks like the oil pump and hex key have been changed but only a visual check and 'ok' on the balancer drive bi-hex keyway, it seems like the new key is still slipping in the original bi-hex balancer keyway when the engine is revved and load increases on the oil pump and this worn keyway. As for the poor running and smoke it could be the cam timing needs tweeking since the belt was changed, if they have VCDS they can check the torsion value and idle stabilisation values. that car's had some money spent on it recently.

[nevo]

Well 10 out of ten for doing all that on warranty,hope the auto box doesn't play up or they'll be pulling there hair out not scratching it.

[tmoram86]

Yeah they've definitely been good about throwing new parts at it without question!!

Taking it back on Monday again and will ask for an oil pressure test and show them what you've advised re. balancer drive. Do you think the best thing to do is suggest that they install the kit linked above by Gazwould?

Taken it out today, did 80 miles in it and no oil pressure alarm until I turned into my street! Strange that it comes and goes like that...

[Gazwould]

Every 77mm PD or CR oil pump drive has to be rectified with proper engineering .

You really should NOT be driving that car !

[nevo]

Not used them myself but he does speak highly of them,there's a lot of people out there doing this job so I would go on his recommendation.,if the pressure test is ok I would give the sender and its connector/ wiring a good looking at.

[tmoram86]

Does the alarm only mean I'm not getting oil pressure at that point in time? Like yesterday, after 80 miles (when I got home) the oil pressure alarm came on... does that mean sufficient oil was being delivered into the engine the rest of the time?
Ideally I wouldn't drive it until it's all fixed, but we're a busy family with no other vehicle at the moment.
The car is going back to the garage 1st thing Monday morning, and they're giving me a courtesy car. I'll definitely relay some of the advice I've been give here and see if I can get them to install a new balance shaft module... presumably my car (2007 BRE engine) has the chain driven one that should be replaced with the gear driven one?
The only other thing I've seen that could affect oil pressure that hasn't already been looked at is the oil filter housing.

[nevo]

Best not to drive it,the pressure switch will alarm at a low threshold maybe 15 psi,not sure of the spec,if its a genuine low pressure you risk screwing up the turbo at least,2007 model should have the gear driven set up.

[tmoram86]

Ok thanks for the advice. I thought the gear driven ones were supposed to be OK, or is it the length and contact of the hex shaft that drives the oil pump that is the issue?

[Gazwould]

Gear doesn't have the chain driven chain tensioner plastic part that fails whipping the teeth to extinction , metal bits in the oil and loss of oil pump drive .

So chain is double trouble as it's both tensioner and 77mm hex drive , primarily caused by the balancer shaft keyway fit and soft material .

Gear , just the 77mm but serious issue .

[nevo]

Basically the key drive is a dumb *** design, but once upgraded will be ok.I suspect once your oil is hot and thin its hovering on the pressure switch threshold.

[Gazwould]

The only way to explain it is they designed it to fail well out of warranty .

Planned obsolescence .

[tmoram86]

So, sorry if I'm asking dumb questions... but even if they replace the whole geared balance shaft module it would still have the problematic 77mm hex? So I'd need to buy the kit you linked me to earlier which has a new shaft and 100mm hex? Or does that kit get installed into my existing balance shaft module?

[Gazwould]

Yes , whole oem 77mm module £1200+ still faulty .

Chain driven upgraded chain and tentioner using better quality parts £240+ but better to convert for £625 to aftermarket geared module as includes 100mm .

Chain to 100mm geared aftermarket remanufactured modified whole module £625+ .

Aftermarket remanufactured modified 100mm chain or geared balancer shaft kit £215 + .

+ labour any tools , sealant , oil change etc .

[tmoram86]

Thanks for all your help here, sorry if I'm asking stupid questions... but I'd never heard of a balancer shaft until I Googled "Audi A6 oil pressure" :)

Chances are then... I can get the 100mm kit that you provided a link to earlier and get my garage to install that on my existing gear driven module? Or as I'm having oil pressure issues is it likely to need the whole module replacing?

[nevo]

These balance shafts counter rotate at twice engine speed so the little key shaft has a hard time,you should have the geared set up already installed so its just a matter of a re- engineered shaft(just the one) with a longer key way (if it is no pressure).

[tmoram86]

better to convert for £625 to aftermarket geared module as includes 100mm .
Chain to 100mm geared aftermarket remanufactured modified whole module £625+
@Gazwould (http://www.vwaudiforum.co.uk/forum/member.php?u=185509), do you know where I can purchase the entire thing from? I think I might have my garage in a position where they are prepared to pay to have the whole assembly replaced, but I don't want them to fit the one that will still have the same problem again later!

By the sounds of what you've said, I can purchase (for around £625) a geared balancer shaft module, that will be compatible with my car, and will use the 100mm part...?

[tmoram86]

I've found this... Looks like the right part?
Audi A4 A6 2,0TDI BPW BLB BRE BRD Oil Pump Balance Shaft Module Reconditioned | eBay (http://www.ebay.com/itm/Audi-A4-A6-2-0TDI-BPW-BLB-BRE-BRD-Oil-Pump-Balance-Shaft-Module-Reconditioned-/261289873662)

[Gazwould]

You do not need a whole module and best stick with well known British .

Kit 9 £215 .

[tmoram86]

Ideal, cheers. I'll suggest that kit to my garage then. I saw on that link for the whole article that they should check for damage to the main crankshaft bearing ... necessary you think?

[Gazwould]

Turbo is first to suffer damage .

[tmoram86]

So safe to work on the assumption that if the turbo is OK that it hasn't caused any fatal damage?

[Gazwould]

Probably if switched off early enough .

My father drove a few miles and I don't know how he got away with it , towards the end the turbo was consuming oil and required a new turbo so px'd .

[tmoram86]

Have I purchased your father's car? 😁 ... Thanks for all your help and advice, it's in the garage now, I've sent them all the info from here and hopefully they'll sort this, and the smokiness/lumpy idle too.

I noticed after I got it back from them last time that the radiator fan seemed to always be running flat out, heard it winding down every time I shut off the engine. Wasn't doing it before it went into the garage!?? One thing at a time though. I'll report back and let you know how I get on.

[Gazwould]

Lol , his was BKP .

Have you a dpf ?

[tmoram86]

There's a note on a previous service invoice that says "No CAT/DPF" so I presume not?

[tmoram86]

Quick update.. In an unexpected turn of events, the garage are booking my car into a local Audi main dealer (Marshall Audi Plymouth) to troubleshoot these problems, give the vehicle a general health check and advise what needs to be done to get it fixed. Fingers crossed...

On a side note, I've never experienced a garage/car sales place so committed to getting problems fixed under warranty. There's been no quibbles and no questions asked!

Hopefully theyll be able to get it sorted soon. Will update when I have more info.

[Gazwould]

Interesting , commitment is a consumer obligation , but as Audi deny the engineering issue that could be awkward in resolving as their own replacement parts / module are inferior.

The other interesting part is Audi will be overzealous in other areas to commission work to turn a 10 year old car into a new one .

[tmoram86]

As long as I'm not paying they can do what they want to try and turn my old one into a new one!
I imagine Audi can run their own diagnostic tools on it which may help identify the lumpy idle, smoking and some other little issues like why the radiator fan seems to have started running at full speed all the time.

10 years old but only done 80k, if they can get this sorted I'm hoping for a good few years of hassle free motoring from it.

[Gazwould]

The oil pump drive has to be upgraded with aftermarket re-enginnered to ensure longevity , my dad's failed at 83k .

[tmoram86]

Surely even if they replaced the balancer shaft assembly and oil pump with original Audi parts i can at least expect another 80k or so out of it??

[Gazwould]

It would be cheaper for the aftermarket better engineered parts to be fitted , plus a good re selling point .

[tmoram86]

So it's booked into the local Audi main dealer on Monday 25th September. Been given a courtesy car until then - a Suzuki Swift :Blush2::Blush2::Blush2::Blush2:

Spoke to the mechanic who was doing the last round of work on the car, and he said that he checked the keyway and balance shafts when he replaced the (in his words) "hex shaft alan key thing" and it all looked good, no wear or damage visible... I'm starting to think that maybe its excessive engine wear, or someone ran the engine with low oil or something like that? Possible that it might go down the route of a new/recon engine??

I've asked for a copy of the information that Audi provide after they've done their troubleshooting/diagnostics on it. Will update when i get further info.

[Gazwould]

I don't think an Audi main ******* is the best idea as they are ignorant to the issue through confliction of interest , how can 15mm of hex key not exhibit wear when it's receptacle is not hexagonal , hard enough and has been rotating at twice engine speed for 80K ?

Fitting a new 77mm key to the balancer shaft keyway that already has wear will accelerate the new key wear .

[tmoram86]

Audi main dealer have said that the engine has suffered internal damage, and recommend that in order to resolve the issues reported to them (low oil pressure, poor running, lumpy idle and smoking) that the most cost effective way would be to replace the engine.
My garage have sourced a refurb BRE engine, from a VW/Audi specialist with 20k less miles than mine. It's going to be fitted this week. It's the engine only, so all the parts they've replaced so far will remain.
Hope to get the car back by the end of the week... fingers crossed!

[Gazwould]

The referbished BRE will S T I L L need Kit 9 otherwise it's back to square one .

[tmoram86]

Yeah, I've emailed them and asked if they would still fit the kit 9 balance shaft upgrade, for the sake of a couple hundred quid, while they've got the car in pieces anyway, to stop me having the same problem again and potentially causing severe engine wear and failure again later down the line.
Waiting to hear what they say.

[nevo]

With all the stories of bad customer service this outfit has bent over backwards to sort you out and need to be commended,sounds like they have been shafted by someone

[tmoram86]

Good news!!! The supplier that they are using to get hold of a refurb BRE engine for me are "well aware" of the balance shaft issues with this engine, and the new engine will come with the upgraded 100mm balance shaft module and oil pump. He said that this will all be detailed on the invoice from them and the job sheet. Sounding good

[tmoram86]

With all the stories of bad customer service this outfit has bent over backwards to sort you out and need to be commended,sounds like they have been shafted by someone

Couldn't agree with you more! I've been shafted by plenty of salesmen and garages in my time, and these guys have been excellent the entire way. The lady that works the desk has been so patient with me, and the mechanics have been really helpful.... I'll probably drop them down a couple of cans of ale once everything is sorted! :) Rest assured I'll be going back there again for any future problems.

[Gazwould]

Amazing .

[NiftyNinja]

I wonder would it be possible to change the shaft if the car was on axle stands

Sent from my SM-G950F using Tapatalk

[Fishrider]

Hi, first post on this forum. There seems to be conflicting info on replacement OEM balance shaft modules.
I’ve read that in October 2009 Audi changed the design of the whole balance shaft modules to accommodate a 100mm hex with longer contact points from the 77mm that wear out quickly and fail.
So if i brought a new OEM module from Audi it would be the re-designed module ( 100mm hex) Or they would still sell the compromised 77mm hex key module?
Cheers

[Gazwould]

What year is your car ?

But regardless it won't be as cheap as the even further bullet proof engineering of the remanufactures .

[Fishrider]

Hi, first registered May 2009. Engine CAHA. Pretty sure mine is the 77 hex version.

Totally get your point about the remanufactured options and the better prices better materials etc.

Just wondered if Audi would be supplying a redesigned module late 2009 version or the older 77mm version.

Might be easier if not more expensive to bolt a new OEM unit on.

Mines on 114k now. No problems so far. If i can get that milage again out of it i'd be happy.

[tmoram86]

Got my car back... new engine, and a few other bits and pieces sorted as well!
Unfortunately, I've still got two problems... ☹

When I start it up from cold, if I leave it ticking over for about a minute or so, it starts chucking quite a lot of greyish blue smoke out the back. Garage put a bottle of injector cleaner in it before they gave it back to me, could it be that? As soon as I start driving, the smoke stops. It only seems to do this when idling after its been sat cold for several hours, if I drive it for a bit and then leave it ticking over when it’s warm it doesn’t produce any smoke at all.

The lumpy idling, with the revs bouncing up and down is still there and seems to be getting worse. I think we presumed it was all engine/oil pressure related. But my old man had a drive in it last night and he’s convinced that it’s a torque converter problem.
At idle, with gearbox in Drive, the RPMs will pulse up and down and it shudders, sometimes quite a heavy shake that you can feel right through the car. If you put it in neutral, it calms down a bit.
I also recently noticed that the radiator fans were running at full speed almost all the time. Aren’t automatic transmissions cooled off the radiator and fans? So possibly If there’s a problem with the torque converter then it’s generating additional heat and the fans are kicking in to cool down the transmission?

[tmoram86]

Fair bit of smoke...


https://youtu.be/lhwEt2Hr0yU

[JMR1]

Hi all, I have been thinking about buying another VAG vehicle, but all these posts about the 2.0 Diesel having oil pump problems are putting me off...is there a definite date where these pump problems were solved at the manufacturing stage? 1st time this problem appeared was in or about 2006??? so had it been eliminated by 2009 or 2010? A friend just bought a 2009 2.0 Ltr A6-Sline, with top specs, would it be safe to say that he will not have any balancer shaft / oil pump problems?
Cheers, :beerchug:
Jim.

[Gazwould]

Started with the A4 B7 in 2004 , ended Feb 2010 .

There are a few rare PD engine codes that didn't receive the twin Lancaster balancer shaft module .

[Fishrider]

My hunch is that servicing and driver technique has a part to play. Reving cold engines from start up and the long 20K servicing schedules probably has a part to play.

[Gazwould]

It's a multiple engineering issue , not driving or oil .

The only way to explain it is it's planned obsolescence , it was designed to fail .

The old proverb 'if it ain't broke don't fix it' doesn't apply to this one , it's one you really have to fix as a preventative .

[JMR1]

Thanks Gaswould, Moral of the story is to avoid ALL 2.0 VAG engines 2005-2010. That's bad form, to take 5 years to sort out a known problem. My Friend with the 2009 A6 S-Line was quite sure that this problem had been solved......I hope that it works out OK for him, the car is a dream to drive.. top specs. I was in my local VW/Audi/Mercedes dealership ( I bought my last two cars from them ) during the week, and the sales man was telling me that he is expecting an 2008 A6 2.0 diesel in as a trade ( he knows the car well, having sold it originally, and fully main dealership service history, so he was confident in recommending it to me, and I am tempted, having sat in my friends S-Line) But not now, after reading the comments here and your input. Most likely, by 2010, there have been modifications carried out on the pump......but obviously it cannot be guaranteed 100% that the problem has gone away.......unfortunately.
Thanks again Gazwould,
Cheers, Jim. :beerchug:

[Gazwould]

I wouldn't totally avoid , just fix it , the re-enginnered modified balancer shaft with deeper harder , perfectly centered hexagonal keyway and longer key are just £215 on their own in parts .

Not all 2008 to 2010 common rail are going to be 77mm , some are an ok oem 100mm , sometimes they can tell you which , sometimes you need to drop the sump and withdraw the key to find out .

[JMR1]

I wouldn't totally avoid , just fix it , the re-enginnered modified balancer shaft with deeper harder , perfectly centered hexagonal keyway and longer key are just £215 on their own in parts .

Not all 2008 to 2010 common rail are going to be 77mm , some are an ok oem 100mm , sometimes they can tell you which , sometimes you need to drop the sump and withdraw the key to find out .
That sounds like plan Gazwould....replace both the keyway, and key. I presume that the chain drives have long been consigned to the rubbish bin ??? Would make good sense at the moment to import a good spec A6 from England, so I will wait for a few month's into the new year, and see what is on offer then. To be able to positively identify one which had the 100mm shaft would be the icing on the cake.. LOL
Thanks again Gazwould,
Jim :beerchug: