XC 60 2.4 Diesel Intermittent Poor Engine Response

[keithewilson]

In the past week, two full tank refills I, have experienced intermittent poor engine response. I thought initially that the fuel may have been contaminated as it went away quite quickly but now is back with a vengeance.

Car will accelerate great through the gears and then after roundabout or bend coming down the gears an inability to accelerate through the gears again.
Or on cruising on the motorway it loses the ability to accelerate cleanly. But then is ok if the foot is taken off the accelerator pedal for a short while and the accelerates ok again, sometimes!

When the problem is happening if I taken the car out of gear and rev it the engine will not rev more than 4000 RPM but under normal operating conditions will rev cleanly to 5000

The car is 3 years old ( and two weeks so out of warranty) 59 plate with 58K on clock and vast majority is motorway miles

I have taken it to independent Volvo man in Southport and his diagnostics say all is good, none of this DPF stuff showing up.

When I drove away from dealer I same poor acceleration.

Anyone any ideas for when it goes back to the Volvo Man?

[craigv60]

I'd suggest checking the simple stuff like vacuum lines and the hose clips that secure the boost hoses to make sure they are all snug and tight. Remove the engine cover and have a nose around.

In my experience, hose clips get looser over time and can leak boost pressure which will cause odd symptoms. Vacuum lines can also get frayed or split, causing random issues.

It sometimes seems to me that mechanics just plug in their laptop and read the diagnostics / error codes without actually LOOKING for simple stuff under the bonnet ... in some cases these simple things may not always throw an error code.