Losing power, EPC light, 03B9 cylinder over pressure code?
#1
07-14-2016, 11:25 AM
Losing power, EPC light, 03B9 cylinder over pressure code?
2013 Audi A4 1.8 TFSI
50K miles
CJEB engine
EPC light comes on when accelerating. Sudden loss of power which remains until engine switched off. Probably disabling a cylinder though not confirmed.
EPC light goes away and power resets to normal when ignition switched off and back on.
On one occasion completely lost power while running at constant 60 mph after EPC came on. Reset OK after stop.
Not consistent
• may trip at 30mph or 70 mph under slow acceleration
• may not trip at all under maximum acceleration to 70mph and redline
• may trip at 3K rpm, may trip at 6K rpm.
• seems easier to trip when car has been running for a while
Engine fault code 03b9 overpressure on cylinder 4?
Sensors reporting OK
Have shuffled plugs and coils around
Have run jet cleaner through
Not finding anything relevant via google. Anyone any ideas, or even know how the car would work out an overpressure condition on the cylinder?
Tia for any info.
Ker
50K miles
CJEB engine
EPC light comes on when accelerating. Sudden loss of power which remains until engine switched off. Probably disabling a cylinder though not confirmed.
EPC light goes away and power resets to normal when ignition switched off and back on.
On one occasion completely lost power while running at constant 60 mph after EPC came on. Reset OK after stop.
Not consistent
• may trip at 30mph or 70 mph under slow acceleration
• may not trip at all under maximum acceleration to 70mph and redline
• may trip at 3K rpm, may trip at 6K rpm.
• seems easier to trip when car has been running for a while
Engine fault code 03b9 overpressure on cylinder 4?
Sensors reporting OK
Have shuffled plugs and coils around
Have run jet cleaner through
Not finding anything relevant via google. Anyone any ideas, or even know how the car would work out an overpressure condition on the cylinder?
Tia for any info.
Ker
#5
11-16-2016, 06:46 AM
So some progress ....
Audi garage said coked up. Had a decoke to no effect. Audi replaced fuel pump and injectors - no effect. Insisted must still be coked up then. Claimed could be caused by carbon on inlet valve and recommended complete strip down. New engine would be cheaper.
Independent garage put camera down into cylinder - clear signs of detonation on the cylinder crown. Don't see now this could be caused by coke on inlet ports so -1 for audi main dealers and audi product support.
Most causes of detonation (thermostat, egr, turbo) that I can read up on would affect more than just one cylinder. Suspect other fault or manufacturing defect. Any ideas?
Will try some lower temp spark plugs and higher octane fuel in the meantime.
Audi garage said coked up. Had a decoke to no effect. Audi replaced fuel pump and injectors - no effect. Insisted must still be coked up then. Claimed could be caused by carbon on inlet valve and recommended complete strip down. New engine would be cheaper.
Independent garage put camera down into cylinder - clear signs of detonation on the cylinder crown. Don't see now this could be caused by coke on inlet ports so -1 for audi main dealers and audi product support.
Most causes of detonation (thermostat, egr, turbo) that I can read up on would affect more than just one cylinder. Suspect other fault or manufacturing defect. Any ideas?
Will try some lower temp spark plugs and higher octane fuel in the meantime.
#7
07-24-2018, 09:25 AM
pretty shi**y deal man...
I have an 07 3.6 Q7 and the timing chain just went on me. 200k miles on it. I think im going to try a **** around and see if i can replace it in my garage. but i hear i need to pull the engine out lol
I have an 07 3.6 Q7 and the timing chain just went on me. 200k miles on it. I think im going to try a **** around and see if i can replace it in my garage. but i hear i need to pull the engine out lol
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