I have a 2007 Volvo S60 2.5T that has been running and idols rough. When I first start the car and the first few minutes of driving it, it drives fine. Once it warms up, it sputters while accelerating. It mostly only does this up to 60MPH, or when I’m slowly accelerating. When I stop at a sign or a light, it idols very roughly. I have replaced the fuel filter and plugs.

 

most common causes of a rough idle are vacuum leaks but can also be caused by a weak ignition or fuel pressure issues. Another possibility is the engine coolant temp sensor. Has the car stored any CEL codes? How did the plugs look when you changed them - all the same color, any signs of hot/cold burn (google for how to read a plug)? How many miles on the car? Any odd behavior in the temperature guage?

 

yes, what codes? You have 2 variable valve timing (vvt) solenoids. If one or both fail, you WILL get the symptoms you described. My son just replaced both solenoids, because of the sludge built up on the solenoid screens. I suggest removing (it's easy) and cleaning with brake fluid. Do you have check engines light? if yes, what codes?

 

I will attach pictures of the codes. There were three codes. The one I didn’t attach is for a cylinder misfire.

 

YES! P0027 (as your scanner says) is for the VVT exhaust solenoid. The VVT solenoids are located on the RH (passenger) side on top of the engine. I THINK the exhaust one is in the back and intake the front one. I would suggest removing and at least cleaning (sludge builds up on the oil screens), but frankly replacing would be better. Kits for the VVT solenoids are $145 and $225 (not sure which is which). This likely causes rough idle. The VVT intake solenoid code is P0026. MAF may need to be cleaned/replaced. Sometimes it can be just cleaned with a carb cleaner, but consider replacing. These things might clear the general misfire code.

 

I want to add a note; Exhaust is in the back, intake in the front for the VVT solenoids. But please do not clean your MAF with carb cleaner, you can damage it. There is specific MAF cleaner at the parts store. Use that. Carb cleaner is too aggressive and can damage it.

I tried cleaning my exhaust VVT and it was fine for a week then the code came back so I replaced to fix it. Cleaning is a good option to try first

 

Dingus 1 is absolutely correct on both counts. Some MAFs can be gently cleaned (with a MAF cleaner) and some not. As I stated above, I would suggest replacing both solenoids and the MAF at this point.

 

also check your PCV - if the oil separator fails it can allow some of the oil to get into the intake which can foul the MAF..

 

I'm sorry for the late response here but I ordered the parts and waited for them to come in. This morning I replaced the Solenoids and hubs for the intake and exhaust. I also replaced the MAF sensor. The car ran great for a couple of hours, then I attempted to go up a fairly steep hill and the issues returned. The check engine light didn't return but the rough idle and sputter returned.

 

OK, check PCV - it's PITA job, because it is under the intake. Also, sometimes new parts can be faulty. Finally, hot flush your engine oil and then replace with new filter. If the car was neglected, you could have sludge build up.