lenaschulz22
Scenic engine knocking combustion issue
Summary of the thread
A 2017 Renault Scenic with 84,069 km is experiencing engine knocking during combustion, leading to reduced power, jerking during acceleration, and smoke emissions. The issue is suspected to be pre-ignition caused by deposits in the combustion chamber. Solutions suggested include checking fuel octane and ignition timing, with a recommendation to have the engine professionally inspected. The problem was resolved by cleaning the combustion chamber and tuning the engine, restoring its performance.
Did this summary help you solve your problem?
4 comment(s)
lenaschulz22 (community.author)
Interesting, thanks for the reply. I've always used the recommended fuel octane, so I'm not sure that's the issue, but I'll double-check. Could you elaborate on your experience with the ignition timing? Was it significantly off, and how did you diagnose it specifically?
victoriaschulz7
Well, my issue was a bit more complex, but it turned out that my car had also deposits in the combustion chamber in combination with some issues with the ignition timing, which caused erratic combustion. Best bet would be getting the engine looked at in a workshop, to be honest. Could save you a load of time and hassle trying to diagnose it yourself.
lenaschulz22 (community.author)
Appreciate the advice! I took it to a local garage, and you were spot on. Turns out there were excessive deposits in the combustion chamber. After cleaning and a bit of engine tuning, it's running like new. Total cost was around 425€, which is better than a full engine rebuild. Thanks again for the help!
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
RENAULT
community_crosslink_rmh_model
SCENIC
victoriaschulz7
Sounds rough. I had a similar issue with my Scenic, though it's an older model. Same symptoms - knocking, power loss, the works. Have you considered what fuel octane you're using? Lower octane fuel can sometimes cause pre-ignition, especially with a bit of age on the engine. Also, when was the last time you had your engine tuned? Might be worth checking the ignition timing, as that can cause similar problems.