Hello everyone and thanks for your time. So i just bought a 2005 A3 Sline Sportback 3.2 V6 Quattro with a 6 speed manual transmission in germany the car has 140000 km. The car is in very good condition the car has been service always at audi in germany.
The car drive fine, no power lost, no timing chain noise.
It started with the engine shaking or stumbling like a random misfire only at idle but when i check with VCDS i had no misfire. When driving no shaking or stumbling.
I have no check engine light, no codes on VCDS.
I check the timing chain on VCDS
Block 208 is at -3.0° Intake Cam Offset
Block 209 is at -1.0° Exhaust Cam Offset
So 2° offset is okay if i understand correctly for 140000 km. Spread should not exceed 3°. The absolute wear limit is 8° spread whether + or minus.
Block 90 & 91 are at 0° so good here too no skipped tooth.
So i change all 6 spark plugs all 6 coils packs i remove the injectors had the injectors clean new oring check for leak and tested. I done an oil change open the old oil filter looks fine.
Change air filter and mass air flow sensor and fuel filter, I had run additive in the fuel to clean the fuel system before removing the injectors. I look for vacuum leak nothing leaking. Check PCV valve no leak from the small hole on the valve cover where the PCV valve is located.
After doing about 4000 km now i see misfire on VCDS the engine misfire on cylinder 2 at random just like before, the engine run good 10 seconds and i get 1 misfire run good for 6 seconds and i get 1 or 2 misfire. Has soon as the rpm increases pass idle the misfire stop. I try swaping the coils and plugs to an other cylinder still misfire in cylinder 2. I have no check engine light, no codes on VCDS.
I try doing a compression test i have 190 psi on all cylinder my coolant level is not going down so head gasket must be good done a leak down test valve are sealing properly.
I brought the car at a audi and vw shop they said it's because of my dual mass flywheel is bad. I know the dual mass flywheel was making a little bit of noise. So brought the car at Audi the mechanic said the dual mass flywheel should not cause misfire. I'm going to look at crankshaft position sensor maybe change it.
I don't know what to do.
Thanks for your help.
Yvan
The car drive fine, no power lost, no timing chain noise.
It started with the engine shaking or stumbling like a random misfire only at idle but when i check with VCDS i had no misfire. When driving no shaking or stumbling.
I have no check engine light, no codes on VCDS.
I check the timing chain on VCDS
Block 208 is at -3.0° Intake Cam Offset
Block 209 is at -1.0° Exhaust Cam Offset
So 2° offset is okay if i understand correctly for 140000 km. Spread should not exceed 3°. The absolute wear limit is 8° spread whether + or minus.
Block 90 & 91 are at 0° so good here too no skipped tooth.
So i change all 6 spark plugs all 6 coils packs i remove the injectors had the injectors clean new oring check for leak and tested. I done an oil change open the old oil filter looks fine.
Change air filter and mass air flow sensor and fuel filter, I had run additive in the fuel to clean the fuel system before removing the injectors. I look for vacuum leak nothing leaking. Check PCV valve no leak from the small hole on the valve cover where the PCV valve is located.
After doing about 4000 km now i see misfire on VCDS the engine misfire on cylinder 2 at random just like before, the engine run good 10 seconds and i get 1 misfire run good for 6 seconds and i get 1 or 2 misfire. Has soon as the rpm increases pass idle the misfire stop. I try swaping the coils and plugs to an other cylinder still misfire in cylinder 2. I have no check engine light, no codes on VCDS.
I try doing a compression test i have 190 psi on all cylinder my coolant level is not going down so head gasket must be good done a leak down test valve are sealing properly.
I brought the car at a audi and vw shop they said it's because of my dual mass flywheel is bad. I know the dual mass flywheel was making a little bit of noise. So brought the car at Audi the mechanic said the dual mass flywheel should not cause misfire. I'm going to look at crankshaft position sensor maybe change it.
I don't know what to do.
Thanks for your help.
Yvan
