Butter
Persistent Cylinder 4 Misfire in BMW 5 Series - Injector Replacement Ineffective
Summary of the thread
A BMW 5 Series is experiencing a persistent cylinder 4 misfire, despite a recent injector replacement. The issue includes a check engine light, loss of engine power, and shaking while idling. Potential causes could be air in the combustion process or a clogged intake valve from carbon buildup. Suggested solutions include checking the ignition coil, spark plug, wiring, connectors, and inspecting for vacuum leaks or performing a compression test.
Did this summary help you solve your problem?
3 comment(s)
Butter (community.author)
community_quotation:
community_author_wrote_on
Start by checking the ignition coil and spark plug for cylinder 4, as these are common causes of misfires. If they are faulty, replacing them might resolve the issue. Let me know how it goes or if you have any further questions.
Sparks and coils were replaced at the same time. Checked the spark plugs and they looked to be operating just like the others I checked. Its weird, when I start the car there’s no driving malfunction but after a while driving in city due to a lot of stops, it pops up usually in 2-3 gear driving manual (automatic transmission). On the highway always 5 gear once I downshift. It’s really like a off and on thing.
CarlyMechanic
community_quotation:
community_author_wrote_on
Sparks and coils were replaced at the same time. Checked the spark plugs and they looked to be operating just like the others I checked. Its weird, when I start the car there’s no driving malfunction but after a while driving in city due to a lot of stops, it pops up usually in 2-3 gear driving manual (automatic transmission). On the highway always 5 gear once I downshift. It’s really like a off and on thing.
Inspect the wiring and connectors for cylinder 4's injector and ignition coil to ensure there are no loose connections or damaged wires. Electrical issues can cause intermittent misfires. If the problem persists, it might be worth checking for vacuum leaks or performing a compression test. Keep me updated on your findings or if you have more questions.
rmh_community_comment_box_header
community_crosslink_scanner_headline
community_crosslink_scanner_intro
community_crosslink_scanner_title
community_crosslink_scanner_price
community_crosslink_rmh_headline
community_crosslink_rmh_intro
community_crosslink_rmh_title
community_crosslink_rmh_subtitle
community_crosslink_rmh_brand
BMW
community_crosslink_rmh_model
5
CarlyMechanic
Start by checking the ignition coil and spark plug for cylinder 4, as these are common causes of misfires. If they are faulty, replacing them might resolve the issue. Let me know how it goes or if you have any further questions.