Car billows blue smoke out and runs lumpy... MAF issue?

Car billows blue smoke out and runs lumpy... MAF issue?

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Discussion

MarkA67

Original Poster:

21 posts

80 months

Friday 24th March 2023
quotequote all
I seem to have an issue with my car (1.6HDi DS3) It runs lumpy to the point it can be felt through the steering wheel and it billows blue smoke out. However, if I take away the MAF sensor via any means it runs absolutely fine... No lumpiness, no blue smoke. I've tried running the engine a multitude of ways trying to pinpoint the issue.

If I simply unplug the connector going to the sensor, it runs fine and there's no blue smoke. If I reconnect the sensor, it will start running lumpy again and goes back to billowing smoke out.

If I disconnect the pipe going from the MAF sensor to the turbo BUT leave the sensor itself connected to the electrical system, the engine also runs absolutely fine. Again, reconnecting the pipe causes the engine to start playing up again.

I've checked all the pipes before the MAF for any oil as well as the air filter but there was none. Is this likely to be caused by a faulty MAF sensor or is there likely a bigger issue? Looking online when they go bad they usually cause black smoke due to over fueling so find it quite odd that in my case it's causing blue smoke.