bradaudi

Took my A4 in to the service department today to have the check engine light diagnosed (going on and off for the last month along with lacklustre turbo performance).

The service writer indicated that the A4 was due for a recall - 15D6 (Cam Adjuster replacement), so recommended they do that as well.

The other item I wanted them to check was a whistling blower fan when the fan speed is set to '4' and above.

I'm not sure these are common issues, but in case this helps anyone, here are the results.......

The cam adjuster was replaced as per the recall notice, but as soon as I started the car I could tell something was wrong. Engine sounded completely off- very rough (checked codes at home - a P0011 - Bank1: Camshaft A(intake). Retard checkpoint not reached (over advanced).

Unfortunately, it was end of day, so wasn't able to point this out to the service writer (will do that tomorrow).

The CEL was going off due to a '5671' Boost Pressure Regulation: Control Range Not Reached (from VCDS). The mechanic ran all the diagnostics on their equipment and could find nothing wrong. Yet the fault is occuring on a regular basis (in fact it threw the code again on the way home from the dealership) - I'm at a loss as to how to convince them they need to fix this issue.

Fan noise - they were able to fix this one. There's a TSB for a loose screw behind the glovebox. So, they successfully fixed that one.

So I left with one new problem, one problem they were unable to diagnose, and one successful repair. Could be worse I guess. Hoping for better luck with my follow-up tomorrow.

QUA77R0

Good looking out! This should have been cross posted but I think AudiWorld missed out on this one.

Blake P reported this camshaft RVU over at Audizine back in July. It seems that Audi is scrolling VIN's to apply the "update" incrementally to avoid overdamnd/undersupply for this needed repair

http://www.audizine.com/forum/showth...vehicle-update)

bradaudi

Thanks QUA77R0. That's definitely the same RVU I had done today.

Curious to see if anyone else has had a similar issue with an install gone wrong on the Camshaft RVU. Given the engine noise I'm now experiencing, I'm assuming there are some parts rubbing together that shouldn't be. Can't be good for the long term life of the engine........

QUA77R0

Could you please elaborate on the engine noise you are experiencing? Is this prior or post camshaft RVU implementation?

Thanks

bradaudi

The noise started after the RVU implementation.

It's difficult to describe....but it's like the normal tic-a-tic-a-tic idle sound has been replaced with a significantly louder wump-a-wump-a-wump idle.

Previously, I couldn't hear the engine, at idle, from inside the car at all, but now it's very easy to hear.

QUA77R0

Sounds like a description of a motor with a hot cam. All the cars that I have swapped cams on have that distinctive lumpiness to their idle but smooth immediately when accelerating. Does yours also smooth out when accelerating or cruising? I'm not sure what is actually done in the camshaft RVU but what you described applies to the installation of hot cams (I don't think Audi is actually replacing the camshafts) or a stock cam that has been overly clocked.

I just read your post on Audizine and would advise that you take your car back to the dealer immediately and talk with the service manager or director. Don't waste time talking with the service adviser. He may be personable but you are concerned about possible engine damage related to a recent repair. A service adviser has NO sway over any technician. The service manager or director can get results from his/her techs.

Is your car performance modified in any way? Tune, charge pipe, HFC, intercooler, etc.? I'm trying to remove potential variables from the equation. BTW, your 5671 (Boost Pressure) code is unlikely to be related and is more often associated with the failure of the notoriously failure prone 2.0 TFSI diverter/re-circulation valve often mistakenly referred to as a blow-off valve.

Hope it helps

bradaudi

Thanks for the info. I've got a call into the dealership, but still waiting for a callback on the 15D6 problem.

As you mention, the sound does smooth out when accelerating, although since the engine noise normally increases as acceleration occurs it's hard to tell if that's just masking the issue.

If it was only the noise, I'd be skeptical, but since the 2795/P0011 fault code identifies the part that was just modified, it seems like the RVU is definitely at fault.

I agree the turbo boost issue (5671) is unrelated to the camshaft problem. It's only relevent in that this was the reason I took the vehicle in in the first place. Instead of repairing the 5671, they performed the RVU and created an additional problem. Now I've throwing both the 5671 boost and a P011(2795) code for the camshaft - so I'm definitely not moving forward.

You mentioned the diverter/ recirculation valve problem on the 2.0 TFSI engine. Do you know if there's a TSB# or something I could reference for my Service Advisor's benefit?

I'm not getting very far convincing them that this is something they need to repair (which may be because they really don't know how to repair it). If it's a common problem (and I'm throwing the 5671 code regularly) then I would expect they would have seen it before and hopefully performed some type of repair - but so far, I've had no luck with these guys.

Do you know the part number on the diverter/recirculation valve - is it N249 or N75? I've seen both listed in other forums as parts that may be related to the problem. The Ross-Tech Wiki also lists N249 along with vacuum hoses etc. as items a mechanic should look at when diagnosing a 5671 issue.

My guess is that the technician limits their diagnostics to what is done with the Audi electronic diagnostic equipment - and probably don't physically inspect any parts when the diagnostics run clean. Therefore, I think I'm going to need to show them a TSB or something to help them find the reason for the boost faults that are occurring (and causing performance problems).

Thanks again for the info.

bradaudi

Service department called back. Talked to the service manager and they asked if I could bring it by for a look. They've got it now - after a quick look it was pretty obvious to the service manager and technician that there was a problem with the installation of the recall. They couldn't explain why they didn't notice this yesterday before giving it back to me.

It's not clear how long it's going to take to repair, although I've asked them again to look into the boost problem as well. I've now got a loaner, so hopefully they'll look after everything while it's in. We'll see.

bradaudi

Got my A4 back today. They needed an extra day to diagnose the problem with the 15D6 recall (camshaft) install.

It turned out to be a failed part (the parts seemed pretty basic, so I'm not sure how that happened). They replaced the part and took it for a significant test drive and verified that all is now fine.

I asked for confirmation that there would be no long term damage and the service advisor indicated that the failure wouldn't affect any other part of the car. It's unfortunate they didn't catch this after the install - but I can't be certain that the part didn't fail when I started it up for the first time (after the technician was completed).

They also corrected the boost pressure problem (5671 code). The service manager indicated that initial diagnostics performed earlier in the week didn't indicate any problems (despite the fault codes), but they verified with a test drive that performance wasn't adequate.

As a result, they replaced Boost Pressure Control Valve (N249)..Part # 06H-145-710-D (I was tempted to point out that I had suggested this when I first brought it in, but probably best to let them diagnose and confirm repair action - not much to be gained by whining).

This is my first Audi (only 2.0 TFSI driven), so didn't have a vehicle to compare performance against. The loaner was 2011 A4, so it provided a good baseline for comparison. With the N249 replacement, I feel performance is close to the 2011 2.0 TFSI and therefore is at the right performance level ("turbo lag" is now gone or minimal).

Might be something to consider for others experiencing performance issues.

A4B8Avant

I know this is much less significant than the cam adjuster matter, but do you happen to have the TSB # for the whistling blower fan?

Thanks.