Please be patient with me as I learn this. Recently, my car has been running perfectly, and then all of a sudden, it decides to wreck my day. It usually revs up to 2k rpms when I start the car on a cold engine and then gradually drops to 800 rpms after 30 seconds so it can warm up and get the oil moving, right? Now when I turn it on, it goes up to 2000, then as soon as it starts to decline and reaches 1.5000, it abruptly drops to 800, after which the needle begins to jiggle up and down from 600 to 1800, and the entire vehicle and engine start shaking and rumbling!?
Issue with the 2007 Audi A4's 3.2L V6 cold start.
- Thread starter Smoker22
- Start date
- Joined
- Dec 30, 2008
- Messages
- 178
- Reaction score
- 5
You need a VCDS scan too see what the MAF is saying and also O2 sensors and what cylinder the misfires are coming from.
Try unplugging your MAF sensor first it could be sending dodgy info to ECU. If no change then do the thing below.
stand at the back of the car when starting it and see wait till it goes to idle if one exhaust is popping more than the other could be dodgy o2 sensor on that bank sending dodgy info to ECU causing lean/rich fuel trim.
is the engine light flashing on the dash, could be a dodgy coil pack, does it sound like it’s dropped a cylinder ? (test each coil pack by removing it and seeing if when you remove it the engine tone changes, when you remove one and it doesn’t that is the faulty coil pack)
not a mechanic but it’s what I would do
Try unplugging your MAF sensor first it could be sending dodgy info to ECU. If no change then do the thing below.
stand at the back of the car when starting it and see wait till it goes to idle if one exhaust is popping more than the other could be dodgy o2 sensor on that bank sending dodgy info to ECU causing lean/rich fuel trim.
is the engine light flashing on the dash, could be a dodgy coil pack, does it sound like it’s dropped a cylinder ? (test each coil pack by removing it and seeing if when you remove it the engine tone changes, when you remove one and it doesn’t that is the faulty coil pack)
not a mechanic but it’s what I would do
Last edited:
