2004 Volvo v70 2.4 idle drop/misfire, when warm

[kev80]

Hi,

I've a 2004 v70 2.4 when it is cold idles perfectly no problem, when it reaches half way on temp gauge on idle it starts dropping to the point of stalling then bounces back up to normal idle.
It had a fault code once of misfire on cyl 3, easy i thought replace coil, but no different, changed plugs still no better, also replaced cam sensor and maf sensor out of curiosity, still no better.
Anyone any ideas as it is getting annoying now, as it also stall at times at junctions?

many thanks.

[abscate]

You need to check all the hoses for vacuum leaks - and also the brake booster valve near the air cleaner box. They often crack and then eventually fly apart.

If its a turbo car, you also have to check induction path for leaks which usually can't be found with a visual inspection.

Quick test. Turn car off, remove key. Find the MAF connector, disconnect. Now start car. Any better after warmup?

You will throw a MAF code when you do this, so you need a way to reset that if MOT is pending, otherwise don't do this.

[oragex]

I don,t think it's related, but take a few minutes to clean the throttle body flap in and out.