Facelift Rough running that I thought was down to dodgy petrol.

8

8YARWY

Electric Avenue
Joined
Oct 10, 2019
Messages
7,238
Reaction score
9,412
Points
113
Location
away
I’ve been experiencing some odd idle behaviour for a few weeks now, initially I’d put it down to a bad fill up from Tesco, maybe the fuel had been sat around too long I thought, however today the idle was quite bad and it started to cut out.
At first no errors were present and no EML was present.
Tonight was different though as it cut out and brought a EML on, scan revealed this
Manifold pressure sensor
There are 2 on this engine one above and one below.
88fbb017f0587829727311c06d37aa42.plist


The RS3 uses these to tell the ECU how much air is entering the engine, so it’s understandable it wasn’t happy.

641ffb79a4d93438d1c411623c1514fe.jpg


As soon as the EML came on the rough idle went away, when I cleared the faults it ‘felt’ rough again.

2 new sensors time I think.


Sent from my iPhone using Tapatalk
 
Had you replaced your cam solenoid before getting this code?
Wondered if they could be linked in some way?
Since it’s implausible signal at 1000 rpm I’d be more inclined to think air leak or something, which took me to an over advanced cam or something
 
Marshy said:
Had you replaced your cam solenoid before getting this code?
Wondered if they could be linked in some way?
Since it’s implausible signal at 1000 rpm I’d be more inclined to think air leak or something, which took me to an over advanced cam or something
Click to expand...

No Cam Solenoid was replaced before.

I initially thought it was down to the petrol then the solenoid but yesterday the rough running returned
I removed the JB4 to rule it out.

However tonight was the first time an EML was triggered with a fault code.

The rough idle has been intermittent.

Sent from my iPhone using Tapatalk
 
T-1000 said:
No Cam Solenoid was replaced before.

I initially thought it was down to the petrol then the solenoid but yesterday the rough running returned
I removed the JB4 to rule it out.

However tonight was the first time an EML was triggered with a fault code.

The rough idle has been intermittent.

Sent from my iPhone using Tapatalk
Click to expand...

Does your car use a similar sensor setup to the R?
Top one measures manifold pressure and the bottom boost pressure?
Ecu constantly measuring differential pressure. Worth changing the top one first?
 
Marshy said:
Does your car use a similar sensor setup to the R?
Top one measures manifold pressure and the bottom boost pressure?
Ecu constantly measuring differential pressure. Worth changing the top one first?
Click to expand...

I believe so yes.

Gonna change em both for piece of mind.


Sent from my iPhone using Tapatalk
 
New Manifold Sensor fitted, fingers crossed everything is now ok.


Sent from my iPhone using Tapatalk
 
A brief write up/guide

Undo the 2 x Torx screws that hold the air scoop in place and remove it.


1c55e10a932e20df1dcea6f331f2e674.jpg

Undo the 2 inner accessible 30 Torx bolts and remove.
81dde364083e60ac2c490cd88b1a7963.jpg


Undo the 3 no 30 Torx bolts leave them loose in the holes though as this will stop the thin metal gasket inbetween from moving out of position.
bac3505a047e2cf213296126b2976281.jpg

Undo this 30 Torx bolt, you’ll need a very short bit for this as room isn’t great.
0157967db13446dac5ff830417988b8a.jpg


Undo the inlet chamber bolts
b1af52970d164bd743aee3a3729c4b2a.jpg


The unplug the boost sensor

54921a49f4b668c3c6f8e308074cf9b8.jpg

You then need to separate the inlet chamber, lift up and pull towards you it’ll rotate towards you enough to access the last Torx bolt at the back, undo this a little to allow the inlet manifold to move towards you easier.

b6daf0feb19c70f9f45dc5e3955acc2f.jpg


You can now access the bolt that holds the sensor on better and remove it and the sensor.
f030cfeeed34d329c51876c879445527.jpg

Then it’s just a matter of inserting the new sensor and nipping up the bolt.

When refitting the inlet chamber you’ll see it locates on the bottom edge first and needs locating on 2 pegs where the gasket is.
815020f3279297f7dbc4ce8376e95d1e.plist


Valves all look pretty clean.

e0d8da206e203b2393f40614ecefe890.jpg


Reassemble and carefully tighten the bolts to 9nm

85b1b199af73c027b96322d22d37b25e.jpg


One point to note make sure the holes in the inlet chamber all line up before you start putting the Bolts back in.
bb8a5591e43bf745a4b67f0c5c78ffd8.plist

Screw the bolts in by hand and torque them up to 9nm starting with the centre one, then the 2 either side, then the outside 2.


Sent from my iPhone using Tapatalk
 
  • Like
Reactions: Ross_T_Boss, savo, DW81 and 2 others
T-1000 said:
A brief write up/guide

Undo the 2 x Torx screws that hold the air scoop in place and remove it.


1c55e10a932e20df1dcea6f331f2e674.jpg

Undo the 2 inner accessible 30 Torx bolts and remove.
81dde364083e60ac2c490cd88b1a7963.jpg


Undo the 3 no 30 Torx bolts leave them loose in the holes though as this will stop the thin metal gasket inbetween from moving out of position.
bac3505a047e2cf213296126b2976281.jpg

Undo this 30 Torx bolt, you’ll need a very short bit for this as room isn’t great.
0157967db13446dac5ff830417988b8a.jpg


Undo the inlet chamber bolts
b1af52970d164bd743aee3a3729c4b2a.jpg


The unplug the boost sensor

54921a49f4b668c3c6f8e308074cf9b8.jpg

You then need to separate the inlet chamber, lift up and pull towards you it’ll rotate towards you enough to access the last Torx bolt at the back, undo this a little to allow the inlet manifold to move towards you easier.

b6daf0feb19c70f9f45dc5e3955acc2f.jpg


You can now access the bolt that holds the sensor on better and remove it and the sensor.
f030cfeeed34d329c51876c879445527.jpg

Then it’s just a matter of inserting the new sensor and nipping up the bolt.

When refitting the inlet chamber you’ll see it locates on the bottom edge first and needs locating on 2 pegs where the gasket is.
815020f3279297f7dbc4ce8376e95d1e.plist


Valves all look pretty clean.

e0d8da206e203b2393f40614ecefe890.jpg


Reassemble and carefully tighten the bolts to 9nm

85b1b199af73c027b96322d22d37b25e.jpg


One point to note make sure the holes in the inlet chamber all line up before you start putting the Bolts back in.
bb8a5591e43bf745a4b67f0c5c78ffd8.plist

Screw the bolts in by hand and torque them up to 9nm starting with the centre one, then the 2 either side, then the outside 2.


Sent from my iPhone using Tapatalk
Click to expand...

I'm sure this will benefit some one T, nice write up mate
 
  • Like
Reactions: 8YARWY
lol........I forgot to put the picture in of the rear Torx bolt that needs slackening off a little to allow the Chamber to rotate forward.

809da625a59c9570743c478ee2fad88a.plist



Sent from my iPhone using Tapatalk
 
Great write-up, I almost took on this job to fit a new throttle body + elbow but decided not to bother, too much conflicting info as to whether it was worth it unless fitting a big turbo. Appreciate the torque details too, that 9nm torque rating explains why I've heard of a few DIYers stripping threads on the runners.

One note - that gasket on the runners has caused a few folks to have minor leaks after being disturbed - so in case there's any issue with it the gasket part no is 07K133379. Personally I was just gonna throw it back on, bit of fairly liquid around the seal and see if it blows bubbles on boost!
 
  • Like
Reactions: 8YARWY
Ross_T_Boss said:
Great write-up, I almost took on this job to fit a new throttle body + elbow but decided not to bother, too much conflicting info as to whether it was worth it unless fitting a big turbo. Appreciate the torque details too, that 9nm torque rating explains why I've heard of a few DIYers stripping threads on the runners.

One note - that gasket on the runners has caused a few folks to have minor leaks after being disturbed - so in case there's any issue with it the gasket part no is 07K133379. Personally I was just gonna throw it back on, bit of fairly liquid around the seal and see if it blows bubbles on boost!
Click to expand...

Yes the inlet chamber bolts could easily strip the aluminium holes I’d imagine.
Even though the 5 bolts have a tapered section at the top of the threads to centre things, it’s worth getting the chamber holes aligned first.

Gasket was in excellent condition so I didn’t see the need to renew, but was aware from the procedure manual that it says to replace that and the metal seals on the throttle body.

I’ve been told by a reliable source that the inlet can leak from the factory.
The manifold to head is a place where it can leak, no wonder I suppose as the tightening torque on that is a 2 Stage affair of 4nm then 9nm.
I think it doesn’t take much to strip the aluminium threads in the head.

Sent from my iPhone using Tapatalk
 
Last edited:
You must log in or register to reply here.

Similar threads

BadBoyWhiteRaps
If you thought your day was going badly...
Replies
62
Views
6K
AudiNutta
AudiNutta
Splathead
I thought that I would be happy with 0-60 in 4.3s......
Replies
7
Views
2K
superkarl
superkarl
jonnyj
Front intercooler to keep temps down
Replies
8
Views
816
Callum66
Callum66
wuta3
Saloon My 2018 RS3 running costs to-date
Replies
0
Views
2K
wuta3
wuta3
Ja5on
RS3 seriously giving it thought
Replies
6
Views
1K
Ja5on
Ja5on
Top
Back