# 645ci Idle Issue



## WHOOSH22 (Oct 13, 2020)

Hi All,
At tickover my 645ci has a very slight misfire which is just barely noticeable.

If I raise the RPM e.g put aircon then misfire goes.

Car runs fine plenty of pull and no error codes are thrown, has had new plugs and coils packs all through.

Any ideas as to what may be causing this?


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## [email protected] (Sep 16, 2016)

Vacuum leak, a smoke bucket will reveal where its coming from. You can get a cheap one off of ebay.


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## WHOOSH22 (Oct 13, 2020)

Hi ,
Thanks for responding, if it was rocker covers would I have an oil leak?

As no oil leaks present checked around them with a mechanics mirror.

Appreciate your help.

Regards
Neal


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## [email protected] (Sep 16, 2016)

Not necessarily, normally with these cars if its running rough, you have air leaking from somewhere. A vacuum line, CCV valve (ripped). If you have a oil leak and have no idea where its coming from, get some of that florescent dye you can put in your oil, again they have the kits on ebay or Amazon. It comes with a florescent light and some come with glasses.


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