I have been having hard starts and the check engine light will come on. I had the code checked and it was p0027 exhaust valve solenoid failure. From my research, I found that sometimes these get stuff in them and get stuck opened, which could explain why I am getting poor fuel economy. I did have an issue with the MAF sensor, which I took off and cleaned and that works great now. How do I repair or replace the p0027 issue?
Also, as a side note, occasionally the engine will make excessive clicking noise which sounds like a knock, but 90% of the time this does not happen. It normally only happens after I have excessively accelerated to pass another vehicle; the knocking will last until the car has sat for a couple hours. Lately, this has been more persistent. Can this be caused by the same issue stated above?
Also note that I am in an area that has NO mechanic that will work on Volvos.
You could have multiple problems going on? For your hard start I would start by attaching a fuel pressure gage to the rail and monitoring the residual pressure. If pressure drops too fast or builds up pressure very slow I would check the fuel pump assembly for an external leak or internal leak causing the loss of pressure. For the exhaust valve solenoid code check your oil level and make sure level is at the proper level. If not that is your problem and your noise might be the valve rattling around because of the low oil pressure. If the level is good you coulld have an internal oil leak from the oil pump pick up tuber seals, very common problem. Quick and easy way to check this is by running engine for a while and then pull oil dipstick out with car running. If oil is foaming you have leaking pick up tube seals and oil pan will need to be dropped. That will cause low oil pressure and set CVVT codes and make the solenoid very noisy. I hope this helps you out a bit and keep us posted please.