cold and hot,,

[t5lover]

well my 855 t5 has a tiny problem when i start her from cold and drive of nicely and easy she is wicked no problems at all running wise but when she is hot or on a long run she will start to miss fire and holding back i have checked the boost pipes and check codes but nothing at all, anyone got any ideas what it could be??

[orse]

Could be a spark plug,ht lead or maybe coil breaking down under heat?Could be worth whipping plugs out checking condition even crack in the rotor arm that is expanding when geting hot.Other than the ignition side engine coolant sensor could be faulty and possibly over fueling the car.Does the missfire clear if revved or is it constant?

[t5lover]

Could be a spark plug,ht lead or maybe coil breaking down under heat?Could be worth whipping plugs out checking condition even crack in the rotor arm that is expanding when geting hot.Other than the ignition side engine coolant sensor could be faulty and possibly over fueling the car.Does the missfire clear if revved or is it constant?

if i get time later i wil double check the plugs and cap leads,, it sort of clears after a few good floorings then its ok i have been told that there is black fuel smoke coming out the back when its floored so it could possably be the temp sender switch were abouts do i find that little bugger?

[orse]

The temp sensor is by the thermostat housing at the block end of the top hose.I changed mine little while back along with thermostat not a bad job.i think i paid about 20-30 pound for it.

[850 2.5 10v]

Might be the same problem as me...

http://www.vpcuk.org/forums/showthread.php?t=23516

I am taking Volvo's master tech out tomorrow to show him the problem - the car apparently never did it with them.

I think it must be temp sensor....

[t5lover]

well i got a spare one see what that does to old girl i will buy some new plugs in a few days time o if that helps the old girl out thanks chaps for your help,,