Dear friends,

My S80 Volvo car check engine light is on, i used OBDII device to test, it shows code P0305 cylinder 5 misfire detected, what is possible reason to have this issue? Spark plug or any other thing? thanks for your help in advance.

 

Worn out spark plugs, bad coil, bad connections, lack of compression, problem with an injector.

How old are the spark plugs? What is the compression on all cylinders? If plugs are old replace with proper ones and move #5 coil to a different cylinder. Drive car. Does code come back? Did misfire move to the new cylinder? If yes you have a bad coil.

 

thanks for answer, i could not find my T30 driver, i am just shopping a new one, i will open the cover and check it after i get new T30 driver. i replaced spark plugs 5 years ago, i only drive 20K miles during last 5 years. anyway, i will replace spark plug. thanks.

 

is this called ignition coil? thanks.

 

Yes and I've replaced hundreds of them on cars. But only when they are bad and always one at a time. and have never used an off brand or the cheapest I could find. Once again, move the misfiring coil to a different cylinder to verify it's actually the coil that's bad (before purchasing parts you think might be bad)

 

Thanks Hoonk. I will check and do as you suggest. do you have coil brand recommendation? if you could send me a link, i would appreciate it.

 

 

thanks.

 

by the way, can anybody confirm cylinder fire order for me, another thread says fire order is like the following,
Firing order 1-2-4-5-3-6,
is this correct? thanks in advance.

 

Sometimes my techs would use a magic marker and label each coil before removal - but it's not easy to swap any - the wiring is just not long enough.

 

can someone help to verify the fire order for 2004 Volvo S80? is it 124536? now i am trying to switch ignition coil between 5 and 4, but cannot figure which one is #5. thanks.

 

#1 is closest to the cam belt, #5 is on the other end. (and in between is 2,3 and 4!) Firing order does not matter. There's no spark plug wires to screw up and the wiring to the coils is not long enough to put the wrong coil in the wrong hole. Label the coils (12345) with a magic marker so you can remember what hole it came from.

Your specific cylinder error code has to do with a specific cylinder, (1234or5) and has nothing to do with the firing order.

 

thanks.

 

Time for a trip to Harbor Freight to pick up a new set of torx bits. No job is work doing unless there's a tool to be purchased :-) +1 on hoonk's comments. Its not uncommon for a coil to break down (a crack in the insulation etc) and not produce enough voltage to fire cleanly under load. Last time I had this, I just bought a single new coil and as noted, count from the nose of the engine to find #5. If it turns out not to be the coil, you can keep the old one as a spare ($50 isn't a huge investment IMHO, and its a common part so eventually you'll need it. You may find it hard to remove the connector but it will come off with constant pressure a bit of wiggling.

 

I'm actually experiencing this right now, according to the manual the firing order is 1-5-3-6-2-4, ...I haven't done my stage 1 tune as I assumed I did before so I replaced all of my spark plugs and I'm still experiencing the same loss of power and shaky idle. I've also switched coil packs and it still read cylinder 5...so I guess my next step would be switching the coil...

 

Have you checked compression?

You need fuel, (the correct amount) spark, (at the correct time) and COMPRESSION.

Injectors rarely fail, but you can swap them to another cylinder to verify operation (as long as the spark plugs are new/verified good) And you can use a noid light to verify each is powered, or even a stethoscope to listen to them clicking.

Coil failure is somewhat common, (more common than a bad injector) - swap coils (and perhaps spark plug) to see if the miss-fire moves with the coil.

What's the compression?

 

Good Day from eastern Canada.
I suggest you do what hoonk has advised. He's on the exact right track.
The cylinder number is physical location starting from cam/timing belt. The error relates to the physical location.

mt6127's comment regarding tools goes right to my heart. I just purchased a set of 'TORX' box end wrenches, now I have; set of male bits, set of male screw drivers, set of female sockets 3/8" drive and the TORK wrenches. All very helpfull on my Mercedes and any Deutz tractor or marine diesels I run across.
Best of luck

 

Had this problem on cylinder 4...bad coil, bad plug. Thank you, about a 20 minute ordeal to replace myself. I spent more time cleaning the engine bay than I did replacing both parts ;-).