2008 s60 P0305 code after timing belt change

bnparson · Post by **bnparson** » 01 Sep 2015, 14:55

I recently changed my timing belt/water pump on my 2008 S60 with 105,500 miles. After driving for about 30 miles in 85 degree heat the car starting to run rough and a P0305 code came up (misfire on cylinder 5). After the sat for about 10 minutes it ran fine.

I swapped cylinder 5 and 2 coil packs and after a time (15-20 minutes) of driving it started to run rough and P0305 code came up (misfire cylinder 5).

Can the timing be off a tooth on the CAMs or crank, with the new timing belt? The car runs with no issues cold.

Can the belt tensioner be the issue? There are 3 adjustments for cold, warm, hot? The belt was changed at about 75 degrees so the adjustment was set to warm (middle).

I swapped the plugs from 5 to 2 but have not tried driving yet.

Any thoughts would be appreciated.

bnparson · Post by **bnparson** » 02 Sep 2015, 05:45

I was able to drive with plugs 5 and 2 swapped and could recreate the P0305 misfire cyl #5. This again was after at least 20 min of running. Its about 80 degrees currently outside (Nice September in upstate NY).

Post by **Vovo_merz** » 02 Sep 2015, 07:14

Try reseting your tension and double check your markings one more time while down there and stop driving it before something bad happens

Post by **oragex** » 02 Sep 2015, 11:07

Next morning on cold engine I would remove the side cover and check see if the needle is still in the middle. How did you final-tighten the tensioner bolt? Too tight and it won't adjust properly on the temperature. It just about 15 ft-lbs so not that much. When adjusting it also it needs to be a bit tight.

bnparson · Post by **bnparson** » 06 Sep 2015, 09:01

I re-adjusted the tensioner and torqued the bolt (15 ft-lbs). I thought this was it but after running for a while (again hot day) I got the misfire on cyl 5 again (ran rough). I shut the car off and removed the side cover. The tensioner was in the hot position. I stared the car and the adjuster seemed to be moving/adjusting a lot. Is this normal

bnparson · Post by **bnparson** » 06 Sep 2015, 09:04

I removed the serpentine belt pulley from the crank so I could see the timing marks easier on the crank. There are two small marks with a long mark on the crank. I think the mark on the block is towards the rear of the car. I cannot see it but I can feel a bump as you run your fingers down a ridge on the block. Is this where the mark should be?

Sardine · Post by **Sardine** » 06 Sep 2015, 18:24

In my car, a 2004 S60, there is a single straight groove each on two adjacent teeth of the crank pulley. Look very carefully, perhaps with an inspection camera if you have one, these marks are extremely hard to see. When the timing marks on the intake and exhaust cam pulleys line up, the mark on the block should point to the valley between those two teeth.
My suggestion is to line up the mark on the intake and exhaust cams then see if the crank block mark is between the two crank pulley teeth that have the grooves.

bnparson · Post by **bnparson** » 07 Sep 2015, 04:11

I verified the timing marks as you suggested. With the serpentine belt pulley off this is easier to see. They all seem to be lining up.

I re-adjusted the tensioner and torqued the bolt (13 ft-lbs). I thought this was it but after running for a while (again hot day) I got the misfire on cyl 5 again (ran rough). I shut the car off and removed the side cover. The tensioner was in the hot position. I stared the car and the adjuster seemed to be moving/adjusting a lot. Is this normal?

Post by **oragex** » 07 Sep 2015, 14:14

The temp needle doesn't move on a new tensioner when the engine is running, either at cold or when hot. Maybe veery little if at all. (in opposition, on my old tensioner that I replaced the needle was shacking quite a bit). When readjusting it, have you fully released the tension like here at 15:00
I think the allen key needle needs to go to counter-clock wise from 11h to 7h to get the needle completely past the notches (at their right), then clock wise until it sits in the middle. It needs to be done from the start when readjusting the tension.

jerseykat1 · Post by **jerseykat1** » 07 Sep 2015, 14:24

its not timing related. you may have an issue with your valve train. maybe a sticking valve or something like that. do a compression test of cylinder #5 when it starts running rough. Do a regular compression test and a running compression test ( incase you are not familiar with it).. hopefully its a faulty injector. Bad injectors are rare but it does happen and they are easy enough to swap to a different cyclinder on your car. so start with the injector swap, see if the misfire follows the injector. don't rip your injector o-rings they are a pain to get. lube them well before you reinstall.. Then check compression.