Lack of top end,fault codes cleared, no eng light - head scratch

A6 All/ S6 All
#1

Hey peps so my car has been running fine until last week.
I had a couple of decent stutters while driving. Like someone was turning the keys off or fuel pumps cutting out. The first time I just filled her up (she was on E) and it went away. It didn’t happen again until I was down to the bottom 1/4 of the tank.

Also I noticed it was not pulling as well as she used to. No misses or stutters just no good pull you get at the 5-7mark. I did have a car full of dudes and or a boat on the back so just put it down to that. After another week I knew it’s still not right and was backing timing/power off a lot. So into the shop for a pro opinion.

Scan came up with
08196 and 08197 passive/sporadic intake manny runner control bank 1/2 stuck open.
00402 pass/sporadic fuel rail sensor “A” circuit low input
06435 active/static check DTC memory of ECM 2
No eng lights came on at all during this time.

We cleared them inspected the manny actuators. Everything appeared to be working as it should. Test drive same as before. Went back and. . . No codes up at all.

There is no miss”s no hesitation just about 100hp less than desired. . . I have a minor oil leak near the top of the head which is causing some smoke after I give it a blast. The only other thing I notice is the cold start / ruff running in the morning is NOT really happening, normally it runs shite for 2 mins as per normal, but this has almost disappeared it starts and then runs almost purrs straight away. It did this went my manifold was gutted and the actuator motors were not working. . . But now they externally are. Haven’t checked inside. New manny and spacers went on 3 months ago

Any ideas?

Many thanks

#2

Just so I understand. You have a new functional intake manifold…

What codes were in ECU 2

Usually a stuck open code would not cause any loss of power but a low fuel code or pressure code can cause a lock of power.

#3

Fuel Filter? or Fuel Pump?

#4

Hey Justin,

yeah we installed a JHM provided manifold with spacers in December about 3-4000miles ago. A shop installed it all as it was a mechanical insurance job.

The shop cleared the codes, and sent me on my way - I have done another 400miles with the car still being rather flat, it felt like the old manifold with the flaps removed, very "wheezy"when the engines loaded up at low rpm, mid rpm it was similar to before. As you would increase the ask of the motor ( start to push it ) the top end 4-6000 suffered.

Update today went back to the shop as the oil leak/smokeyness has continued - scanned again, same codes of 08196 and 08197 are up. Sporadic intake manifold runner control bank 1 and 2 stuck open. Unsure on ECU, it did bring up control bank 1 with check DTC mem of ECM 2.

We test drove me with the mechanic, times it was good, times it was boggy and poos, then times it performed, all changing within the 10min drive.

What are the major causes of these being stuck open? the motors and arms at the front are moving when revs in neutral…I did get the spacers installed which I know can cause clearance issues.

Its weird I had a fews months of trouble free driving then sudden issues. Also weird NO eng light

The fuel issue / fault has never returned - putting that down to running it on low gas levels (10miles to run etc)

#5

The only issue I have seen with the flaps stuck open is people that have not removed the motor pull brackets when installing the intake spacers. It would seem like a very obvious thing but it seems some don’t always think about it.

Stuck open with the flaps you would need to see the travel in the arms. you can run a test for the flaps in vag com and from this you can watch the linkage to make sure nothing is getting bound up.

#6

Its funny how you guys who specialize in S6s get it correct 99% of the time.

back to the shop - got the mechanic to drive this time, funny how a crap running S6 feels fast to a non S6 driver…

we could agree the bottom end was off, boggy and slow - top end seemed not too bad…this shows how massive the intake is on performance on these cars…not only the plastic flaps but the lower metal runners too.

So when my parts turned up I sent the shop the link for the manifold and spacer install off this website, I saw that they had removed the lifting bracket one side, but didnt notice they had NOT removed the bracket and aux bracket thats mounted to the lifting bracket on the US drivers side, I could then see a tiny mark on the very top of the actuator arm - where it was just hitting the bottom of that bracket. Shop must not have looked at the info I provided…

This bracket is shown in the specific “manny removal” post - it defo a must, my car drove for 4000miles before it became a problem - but it still did.

When you rev the car in N that system ( the bottom flaps ) move but must only move a part of the way, when you drive it must move to its full range of motion, which would stick…power loss was noticeable particulary under 2,000rpm. Best test / tell was put it in manual mode in a high gear and try and drive at low rpm…she runs porr and then just down shifts to redline to compensate. It also requires a heap more throttle pedal movement when your in top gear cruising at highway speeds when under 2,000rpm - or towing.

As Justin said either vagom or follow the GUYS WHO KNOW!!!

my biggest issue, zero eng lights, only “passive” faults meaning it was all seat of the pants awearness until you scan it.

additional positive the oil leak/smoke has also stopped, im guessing it caused some funky pressurization of the head during all this business.

#7

Well that’s a great one to cross off your list. I have heard that same story over a few times. Where a member here will give a shop a heads up and show them the install post and the shops just ignore it only to have issues later… shame

Good to hear the car is back running in good shape.