S3 - Hesitation in 5th & 6th

mattyboy199

mattyboy199

Registered User
Joined
Nov 13, 2005
Messages
1,996
Reaction score
49
Points
48
Location
UK
I've been experiencing hesitation in 5th & 6th, initial thoughts were to replace the plugs which did improve things generally but on a 100mile trip today its still occurring.
coil packs - no
plugs - no
dv - no
crank sensor - no
N249 - no as the issue was occurring before the delete

The funny thing is the car pulls very well in every other gear. The hesitation occurs between 3000 - 4000 rpm & isn't consistent at all.

Has anyone has similar issues ?
 
I'll do a scan tomorrow. Everything listed above has been recently replaced fuel pump included. Its not clutch slip as that is only 25k old & i know what clutch slip feels like. Its feels like the boost drops off & then picks back up.
 
as expected :-(

VCDS-Lite Version: Release 1.2
Sunday, 13 March 2016, 15:32:14.


Chassis Type: 8L - Audi A3/S3
Scan: 01,02,03,08,15,16,17,22,35,37,45,55,56,57,75,76
-------------------------------------------------------------------------------
Address 01: Engine Labels: Redir Fail!
Controller: 8N0 906 018 BH
Component: 1.8L R4/5VT 01 0001
Coding: 10710
Shop #: WSC 00000
VCID: 78836BE34BCB

No fault code found.
Readiness: 0000 0000

-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: None
Controller: 8N0 907 379 E
Component: ESP 20 CAN V005
Coding: 18448
Shop #: WSC 01236
VCID: 3E0FBDFB296F
No fault code found.
 
is it speed related rather than rev related?

The max torque is in that range is it possibly related to haldex, CV joints, wheel bearings or rear brakes binding? - just as a non turbo based approach.
 
I had this on mine. I went down the route of changing speak plugs, inspecting the Coil pack wiring, and coil pack checking hoses etc etc.
It turned out to be a simple fix. My hose to my Fuel pressure regulator had split, so it wasn't connected, once snipped and refitted i've never had any issues whatsoever.

Worth a look
 
Stuart B said:
is it speed related rather than rev related?

The max torque is in that range is it possibly related to haldex, CV joints, wheel bearings or rear brakes binding? - just as a non turbo based approach.
Click to expand...

Gosh I've no idea its very difficult to determine where exactly it is coming from, i know brakes aren't binding, bearings are good, CV joints front & rear are sealed...just leaves the haldex

S3 ROCKS said:
I had this on mine. I went down the route of changing speak plugs, inspecting the Coil pack wiring, and coil pack checking hoses etc etc.
It turned out to be a simple fix. My hose to my Fuel pressure regulator had split, so it wasn't connected, once snipped and refitted I've never had any issues whatsoever.

Worth a look
Click to expand...

Not sure where i can find this, where is it located ?
 
Open your bonnet and remove your plastic engine cover. You'll then see your injector rail that plugs into the inlet manifold at the front. On the right hand side of the rail there is a small Fuel pressure regulator with a hose connected. Just check the condition of the hose and ensure its not split and is connected

1179-4718-large.jpg
 
Have tried driving with the esp turned off? It may be related to one of the esp sensors, or possibly it could be your n75 valve at fault.
 
S3 ROCKS said:
Open your bonnet and remove your plastic engine cover. You'll then see your injector rail that plugs into the inlet manifold at the front. On the right hand side of the rail there is a small Fuel pressure regulator with a hose connected. Just check the condition of the hose and ensure its not split and is connected

1179-4718-large.jpg
Click to expand...
Any joy Matty
 
audi upgrades
ayfreetee said:
Have tried driving with the esp turned off? It may be related to one of the esp sensors, or possibly it could be your n75 valve at fault.
Click to expand...


I've driven with the esp off, no change, could I just unplug the n75 and see how it behaves?
 
you can drive with the N75 unplugged - at least it will give you an idea of whether it is working at all or not - there is quite a difference in my opinion, 6-8psi boost only, in my car it feels like the handbrake is on (which it probably is)

I have previously had a problem where the car was fine when I first started a journey then after a few miles the boost would not go over 0 - very noticeable in 6th when I would normally put my foot down on the motorway to pass a car. I fitted a catch can thinking it was engine muck or PCV leaks, and trimmed the TIP which was a bit kinked after fitting a heat shield.
 
I would start at a smoke test if you have a local garage who can do this for you.
Majority of these cars have leaks.. and it plays havoc.

Else find your local vag independent who is capable of diagnosing it.. Try not to throw parts at it and hope it fixes it.. you may end up wasting money on bits you didn't need.
 
a fault appeared today, quite happy about this...now what could this be...

VCDS-Lite Version: Release 1.2
Saturday, 14 May 2016, 17:17:35.


Chassis Type: 8L - Audi A3/S3
Scan: 01,02,03,08,15,16,17,22,35,37,45,55,56,57,75,76
-------------------------------------------------------------------------------
Address 01: Engine Labels: Redir Fail!
Controller: 8N0 906 018 BH
Component: 1.8L R4/5VT 01 0001
Coding: 10710
Shop #: WSC 00000
VCID: 78836BE34BCB
1 Fault Found:
17544 - Fuel Trim: Bank 1 (Add): System too Lean
P1136 - 35-00 - -
Readiness: 0000 0000

-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: None
Controller: 8N0 907 379 E
Component: ESP 20 CAN V005
Coding: 18448
Shop #: WSC 01236
VCID: 3E0FBDFB296F
No fault code found.
 
I think its a vacuum leak i know my PCV system has leaks, I've look at delete diagrams but i find them hard to follow & images are incomplete. I'd like to replace the whole system with silicone pipework & T pieces etc just not sure what sizes etc & the routing of the system.
 
A9y3u5as
I've found my split, its a pipe that sits under the one that's connects to the inlet manifold, i've indicated in the image. I cant seem to find this pipe on any diagrams though.
 
I'm pretty sure creation Motorsport do a replacement maybe forge also
 
Well I've taken the car out and seem to have lost a lot of boost. The dv noise has also changed to a flutter noise rather that just a normal dump.

I haven't cleared or re-scanned for faults yet but it's not running right, it's also seem to idle close to 1000rpm....so confused
 
are you sure you connected that junction up right? on my AMK unless you have deleted the PCV they were three pipes involved on the throttle body side, there is another pipe that goes from that area but to the brake servo next to the firewall.
 
Yes in the 2nd photo to left is that very pipe I just lifted it up to get a good shot of the new pipe
 
oh I see, so when I was mucking about with my leaks (and deleted the PCV), I actually caused another one further up next o the firewall on the other end of that hose you have moved out the way.

That leak caused an erratic idle and engine even cut out, the join doesn't have any clips on it is like a push fit, but mine was loose so I put a jubilee clip on it.

Leak
 
Ok so thought check her over today...firstly my n249 by pass pipe has come off (manifold end) probably something to do with yesterday's pipe replacement. Also I've found a sheared pipe from the fuel rail but not sure where it goes...
DSC 0098
DSC 0099
 
All solved, the fuel rail piping is a vent to the underside of the manifold next the n249 nipple. Cars running as it should and feels a bit more pokier
 
that's not a 'vent'; that pipe is the fuel pressure line which the fuel pressure regulator uses to govern the fuel pressure. With that split pipe the fuel would be injected at 3Bar all the time regardless of the inlet manifold pressure and the fuelling would be way off; lean at full boost
 
Alex C said:
that's not a 'vent'; that pipe is the fuel pressure line which the fuel pressure regulator uses to govern the fuel pressure. With that split pipe the fuel would be injected at 3Bar all the time regardless of the inlet manifold pressure and the fuelling would be way off; lean at full boost
Click to expand...

Well whatever it is I've replaced the pipe and it's running fine
 
  • Like
Reactions: SamHendry
So long as the fuel pressure reg is connected to the inlet manifold all is ok. Just needs to see boost.
 
The FPR always needs the vac like to the inlet manifold. Don't T that line either for any gauges.
 
mattyboy199 said:
Well whatever it is I've replaced the pipe and it's running fine
Click to expand...


I'm glad you found your way with the problem, as it usually is with cars you're unfamiliar with, it tends to be a rabbit chase with pipes! Check them all closely, take them off if you have to.
 
I'm amazed how different the car feels, it's boosting so well. I recommend everyone checks these pipes.
 
You must log in or register to reply here.

Similar threads

W
Flat spot @5prm in 5th and 6th
Replies
8
Views
2K
WRN
W
B
audi s3 powerplaying up in 4th, 5th, 6th gear?
Replies
5
Views
1K
badger5
badger5
scotty_24
Loss of boost in 5th 6th only
Replies
29
Views
2K
scotty_24
scotty_24
S
audi s3 8l 2000 model holding back in 5th and 6th
Replies
2
Views
1K
s3arekid
S
M
5th and 6th gears gone AWOL
Replies
1
Views
898
Alex C
Alex C
Top
Back