Help 2005 S40 2.0d intermittant rough running

[dragonuk2000]

Hi guys

Please can anybody give me any pointers about a new problem that has developed with my beloved S40.

My wife who now drives the car said that for the lat few weeks everytime she puts fuel in the car it has developed an intermittant problem, when she is running on the motorway for the first time after fueling at 70 to 80 out of the blue the car will start to 'cough' and loose power with rough running with no dashboard errors/fault codes. Sometimes the car will rectify itself after a very short time and other times she needs to pul over to the hard shoulder stop the car and restart after a minute or two, when she pulls over the car has a very rough idle and sometimes stalls of its own accord however after the restart it drives fine with no power loss or rough running. I have taken it out and suprise suprise its not done it to me and I am at a loss.

I have had the EGR changed in the autum last year due to it throughing up fault codes so cant realy be that and the car had a full service in the second week of Jan at a Volvo main dealer so all the filters should be clean and clog free. I have asked her where she gets fuel and it is V-power shell at a few different stations.

The only thing I have noticed when looking under the bonnet is that while running there seem to be regular air bubbles travelling through the clear fuel pipes that are visible under the engine top cover would this be relavent to the problem?

I dont really want to take her back into Volvo yet as its an intermittent problem and chances are it wouldnt occure.

Please if anybody has any ideas to help me restore my baby back to perfect running order I would be most greatful.

Matt

[EricMe]

If it only happens after refuelling - particularly if tank has been completely filled - it might indicate a blocked tank breather pipe.

Or of course adding fresh fuel to the tank might be stirring up the contents and leaving water drops suspended in fuel.

[kebab10]

You dont want air bubbles in the fuel line. Would suggest you take the car to a dealer or good indy and get the fuel filter replaced at the very least. You have air entering the fuel system somewhere and ou need to find out where. Fuel filter is a good start. Hope this helps.

[kebab10]

Just had another thought. dont let the tank get too low. Fill up at half tank but definitely get the fuel filter changed.

[dragonuk2000]

Thankyou for the replies guys, EricMe I had thought about water being stirred up during the fuel intake I remember a long while back there used to be an additive you could add to the tank to get rid of it do you know if this is still available?

Kebab10 she has already been to the dealer 4 weeks ago for a full service so I would have thought that they would have changed the fuel filter during that, it was a 92000 service. I didnt think I should be seeing little bubbles in the fuel line, hmmm I wonder if the stealer changed the fuel filter and either didnt re-attach the intake pipe or broke a line during the service either tank end or engine end.......

[Guru]

The fuel filter plastic housing becomes distorted over time, and the housing cap then fails to create a perfect seal thus the air bubbles

The fuel filter housing design has been revised and there's a new improved housing design now which assures perfect vacuum, worth an inquiry at your local V dealer.

[kebab10]

Never, ever assume that the stealer has done x and y on a service. Never, ever trust them, ever. Some are good dont get me wrong. Anyway, check that they have actually done the fuel filter.
Give them a ring and see what they did.