Photos and information in this post are for entertainment value only.
2015 Audi A3 2.0T, 98K.
After a spark plug replacement (NGK) and walnut blast service for maintenance, the engine developed a cyl #4 misfire under heavy acceleration only. Clearing the misfire adaptives resolved the issue for a few hundred miles, but the misfire returned. Freeze frame data on my Autel was worthless. So, more diagnosis was needed:
Valvetrain picture. Oil was leaking into the spark plug tubes. Plus it was an opportunity to check for broken valve springs.
Compression Tests:
#1:
#2:
#3:
#4:
Leakdown Test:
#1:
#2:
#3:
#4:
Compression and leakdown tests were fine.
Since I was only given a Saturday to sort this out, in the interest of efficiency, I replaced the #4 injector (which meant removing the intake again), installed new Genuine VAG spark plugs and installed a new Genuine VAG oil separator. So far, the misfire has not returned after 500 miles.
New/old. Apparently you have to buy the 3-prong clip separately; it is not included with the new aftermarket Bosch injector.
2015 Audi A3 2.0T, 98K.
After a spark plug replacement (NGK) and walnut blast service for maintenance, the engine developed a cyl #4 misfire under heavy acceleration only. Clearing the misfire adaptives resolved the issue for a few hundred miles, but the misfire returned. Freeze frame data on my Autel was worthless. So, more diagnosis was needed:
Valvetrain picture. Oil was leaking into the spark plug tubes. Plus it was an opportunity to check for broken valve springs.
Compression Tests:
#1:
#2:
#3:
#4:
Leakdown Test:
#1:
#2:
#3:
#4:
Compression and leakdown tests were fine.
Since I was only given a Saturday to sort this out, in the interest of efficiency, I replaced the #4 injector (which meant removing the intake again), installed new Genuine VAG spark plugs and installed a new Genuine VAG oil separator. So far, the misfire has not returned after 500 miles.
New/old. Apparently you have to buy the 3-prong clip separately; it is not included with the new aftermarket Bosch injector.
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, walnut blasting does a great job at cleaning the valves. I know of one case where some one did it but the valves where not fully closed and the walnut stuff got inside the engine.
