2012-2015 BMW 3-Series and 4-Series Forum
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read
BMW 3-Series and 4-Series Forum (F30 / F32) | F30POST > Technical Forums > N47 and N57 Turbodiesel Engine / Drivetrain / Exhaust Modifications > F30 320d 2012 rough idle and rough engine
Post Reply
Thread Tools Search this Thread
      10-25-2020, 01:08 PM   #1
United Kingdom

Drives: F30 BMW 320D
Join Date: Oct 2020
Location: Uk

iTrader: (0)

F30 320d 2012 rough idle and rough engine

Hi everyone. I am having issues with rough idle and bad engine performance.
Things done:
Cleaned air intake manifold
Checked for leaks on air intake pipes
Replaced MAF sensor
Cleaned EGR valve
Changed oil, oil filter, air filter, fuel filter.
Checked injectors all read same resistance

When car is idling the Maf sensor reading goes erratic from 1-14g/s up and down, not smooth graph

Oxygen sensor reads 0.980V but when accelerate it drops to 0.2V and when let accelerator go it jumps to 1.2Volts and goes back to 0.9Volts.

It is the same at idle or warm engine.

Car was vibrating before as it would have bad flywheel but after cleaning all sensors and air manifold it stopped vibration so not flywheel after all.

What can cause erratic readings for Maf and oxygen sensor 1.2V reading.

Just to add I cleaned MAP and crankshaft sensor too.

Throttle position is 85% at all times. When stop start it goes to 14%

All pulleys are new including crankshaft pulley. Car has 157k miles on the clock
Appreciate 0
      10-25-2020, 04:46 PM   #2

Drives: 328xd Wagon, M2 Competition
Join Date: Jun 2018
Location: Houston

iTrader: (0)

The throttle is usually zero during run, hmm.. I wonder if it's related.
Appreciate 0
Post Reply


f30 engine not smooth, f30 rough idle

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

All times are GMT -5. The time now is 09:45 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST