[Kitsunekyle]

Hi All, hoping you can impart some knowledge on me.

I have a 2013 S60 2.5L turbo. I have 89k miles on the car.

I was driving to work Monday a 59 mile drive. 10 miles from work I got cel try slow down or shift up. The car seemed fine so I slowed down and continued to work. I only noticed a change when I got to lower speeds 40 miles and under, very rough idle with rpms shifting between 600-750. I ran obdII scanner and got codes P0300 and P0304. After checking the forums I saw this commonly fixed by changing spark plugs and coils. I figured since I'm doing one why not do them all. I changed out all 5 spark plugs using NGK iridium's and Bosch ignition coils. Cleared code and started it back up and after about 15 seconds it began a hard idle again. After the replacement I checked the plug for the injector on cylinder 4. Pulled plug free and there was no change in idle. Plugged back in again no change in rpms. So I figured injector 4 was bad. So the next day I pulled the fuel rails and swapped out the injector for cylinder 4. Cleared code and started her up again. The car was still misfiring. I traced wires and could not find any in harness that looked bad or frayed. I decided to bring the car home. During the drive I got cel again and now I show misfire in 3,4,5.

Thoughts on what this could be?

I bought the car with 60700 miles on it in January and all service prior was done by Volvo. I am religious about oil changes every 5k miles. I only run premium fuel in it.

 

[t6.mohamed]

Is it intermittent or a constant misfire?

 

[ecoDrive]

I changed out all 5 spark plugs using NGK iridium's

This could be your problem. This engine is very fickle when it come to plugs. Many reports here of what you experienced with aftermarket spark plugs but after changing the plugs back to new Volvo brand misfires solved.

Once you do that you can better troubleshoot the injector issue.

 

[Kitsunekyle]

Is it intermittent or a constant misfire?

It's hard to say once I got the car up to speed she felt like everything was running normal strangely enough my gas mileage did not tank on the way home. I'm usually running about 30 to 31 miles per gallon average my trip home was 32.6.

 

[Kitsunekyle]

It's hard to say once I got the car up to speed she felt like everything was running normal strangely enough my gas mileage did not tank on the way home. I'm usually running about 30 to 31 miles per gallon average my trip home was 32.6.

The misfires in three and five may have been an isolated thing I thought to delete the codes and then drive it a bit more to see if those two came back up but with all the issues I really don't want to drive it if I don't have to 😅

 

[t6.mohamed]

It's hard to say once I got the car up to speed she felt like everything was running normal strangely enough my gas mileage did not tank on the way home. I'm usually running about 30 to 31 miles per gallon average my trip home was 32.6.

Does it seem to misfire under boost?
I changed the coils on my car very recently when one went bad and caused a misfire. After I changed it, the car still misfired until I figured out my airbox lid was loose.
Maybe you have a leak somewhere in the intake system?

 

[budleach]

This could be your problem. This engine is very fickle when it come to plugs. Many reports here of what you experienced with aftermarket spark plugs but after changing the plugs back to new Volvo brand misfires solved.

Once you do that you can better troubleshoot the injector issue.

Hard to say if OP even has any injector issue at all. If there is no spark in the cylinder, unplugging a working fuel injector would not change anything.
Fuel + No Spark = No Bang
No fuel + No Spark = No Bang

EDIT: That comment was directed more at ecoDrive. Based on the the thread title you (the OP) clearly have a pretty good understanding of what parts have already been eliminated as possible culprits.

 

[Kitsunekyle]

Does it seem to misfire under boost?
I changed the coils on my car very recently when one went bad and caused a misfire. After I changed it, the car still misfired until I figured out my airbox lid was loose.
Maybe you have a leak somewhere in the intake system?

Actually the car seems fine under boost. I Will recheck the intake system when I get home regardless. The work was done in the parking lot after work in the dark with headlamps.

 

[Kitsunekyle]

Hard to say if you even have any injector issue at all. If there is no spark in the cylinder, unplugging a working fuel injector would not change anything.
Fuel + No Spark = No Bang
No fuel + No Spark = No Bang

Your diagnostic steps are logical, after replacing coils and plugs you can assume you have spark. But that may not actually be the case if there was some other cause for the no spark.

Correct, I measured voltage to the spark plug but after 3 and 5 had a misfire I am thinking of rechecking the grounds. I think I read the cylinders 3-5 all share a common ground. Though is it possible the misfires in 4 cause the engine to stutter which threw me codes for 3 and 5? I am not sure how to determine how often those cylinders are misfiring. I was also considering checking the vacuum line to cylinder 4. The car has 89k miles on it but it's also 10 years old and was not being driven for quite some time. Could a dry rotted vacuum line cause the original misfire in cylinder 4?

 

[Kitsunekyle]

This could be your problem. This engine is very fickle when it come to plugs. Many reports here of what you experienced with aftermarket spark plugs but after changing the plugs back to new Volvo brand misfires solved.

Once you do that you can better troubleshoot the injector issue.

At this point I don't think it was an injector issue at all. I checked ohms on the solenoid and the variance was only .1 off from my highest. I thought even if the injector was good that maybe it was clogged and needed cleaning. I kept it for this reason thinking I could clean it at some point and reuse it.

 

[budleach]

Might want to do a compression check just to rule out any major mechanical issues. You have already checked spark and fuel mechanical components, only one left to check is air. Do you have any issues with oil consumption?

If compression checks out, then problem would seem to be electrical in nature. Could be a wiring issue or ECM issue for either coil or fuel injector.

 

[budleach]

Maybe install a new plug and start the car and let it idle for a couple minutes then inspect the spark plug on cylinder 4

If it is clean and wet, you are getting fuel and no spark.

If it is clean and dry, you are getting no fuel. May or may not be getting spark.

If it has evidence of heat/combustion you have an intermittent loss of fuel or spark.

 

[Kitsunekyle]

Might want to do a compression check just to rule out any major mechanical issues. You have already checked spark and fuel mechanical components, only one left to check is air. Do you have any issues with oil consumption?

If compression checks out, then problem would seem to be electrical in nature. Could be a wiring issue or ECM issue for either coil or fuel injector.

I am having an issue with oil consumption roughly 1 quart per 2500 miles. Though it seemed a little low but I was parked on an incline. Hoping it's not a compression issue but if I'm consuming oil I suppose that could result in a burnt valve...

 

[budleach]

I am having an issue with oil consumption roughly 1 quart per 2500 miles. Though it seemed a little low but I was parked on an incline. Hoping it's not a compression issue but if I'm consuming oil I suppose that could result in a burnt valve...

Yeah, a burnt valve and/or scored cylinder walls.

Hopefully it's not that serious.

 

[Kitsunekyle]

Worked late and had an obligatory Christmas party to attend. This is my focus the next from after work today until Sunday night.

 

[Kitsunekyle]

Going to warm the car up and check what budleach said determining if the cylinder

Is getting spark and or fuel. Compression check will come next. Pictures will come with

 

[Kitsunekyle]

Car does not seem to be idling as rough as it was the other day but it is still idling harsh once it drops below 1k rpms.

 

[Kitsunekyle]

Cleared the codes from the OBDII scanner. Now it just reads misfire cylinder 4 pending.

 

[Kitsunekyle]

 

[Kitsunekyle]

View attachment 175480

All other spark plugs look good. They show signs of combustion. Cylinder 4 looks wet and seems to have slight oily residue. Doing compression check now.