Hi all,i am a new volvo owner,i have just aquired a volvo v40 t4 1999 from my brother inlaw.
My brother-in-law loved this car,but one day the engine revved up to about 4000rpm whilst in park and then droped again after a few seconds,and whilst driving the car seemed to pull constantly,this had never happened before,if you pulled over and stopped put into park it would high rev again then drop.Now i have it i noticed after taking around the block to try and charge battery,and while engine was still warm,turned off and the battery did not have enough power to turn over,so go out the jump leads,the engine was turning over but seem to struggle to start,while it was warm,when it did finally start it revved high(4000 rpm) for about 10 seconds then dropped again.
Now when the engine is cold the engine fan comes on after i turn the ignition on,but dont start the car,and then without starting turn ignition off the fan stays on for about 3 to 5 mins,
please help,someone told me it could be a cooling temp sensor,or engine temp sensor.Please help worried volvo owner !Steve

 

I would replace the ECT and thermostat.
Also have the battery tested.

 

Many thanks.Ihave ordered a thermostat and ect,which should be here over the next couple of days,will let you know the outcome.

 

Many thanks,changing the ect and thermostat,has stopped problems,although the idle seems to drop to low occasionally,thanks.Steve