misfires on 3, 4 & 5
06-19-2019, 12:45 PM
#1
misfires on 3, 4 & 5
New guy here again...bought my '03 2 weeks ago. Drove it home 900 miles without any problems. Three days later it was in the shop to get the IMSB/RMS/clutch trifecta done. Car was driven home from the shop (25 miles) last Friday.
Not driven again until yesterday...7 miles from home CEL ("drive to workshop") came on. Turned around and took the car home. Took it back to the shop this morning - error codes are misfires on 3, 4, 5. Mechanic's initial guesses at the cause are a) vacuum leak, b) bad plug(s), c) bad coil(s). He started the car at the shop and thought it initially sounded a little rough, although it smoothed out after a few seconds. First thing he's gonna do is smoke test it.
So, just a coincidence that this happened soon after getting the IMSB replaced? He's not a noobie at doing them; says he's done 50 or so. If the engine is getting moved around a bit, how hard would it be to break some plastic connector that would result in a vacuum leak?
Not driven again until yesterday...7 miles from home CEL ("drive to workshop") came on. Turned around and took the car home. Took it back to the shop this morning - error codes are misfires on 3, 4, 5. Mechanic's initial guesses at the cause are a) vacuum leak, b) bad plug(s), c) bad coil(s). He started the car at the shop and thought it initially sounded a little rough, although it smoothed out after a few seconds. First thing he's gonna do is smoke test it.
So, just a coincidence that this happened soon after getting the IMSB replaced? He's not a noobie at doing them; says he's done 50 or so. If the engine is getting moved around a bit, how hard would it be to break some plastic connector that would result in a vacuum leak?
06-19-2019, 12:48 PM
#2
Rennlist Member
Very easy...Lets see what the smoke test shows. You should be fine. When where the plugs and coils last changed (if ever)?
06-19-2019, 01:42 PM
#3
06-19-2019, 01:43 PM
#4
New guy here again...bought my '03 2 weeks ago. Drove it home 900 miles without any problems. Three days later it was in the shop to get the IMSB/RMS/clutch trifecta done. Car was driven home from the shop (25 miles) last Friday.
Not driven again until yesterday...7 miles from home CEL ("drive to workshop") came on. Turned around and took the car home. Took it back to the shop this morning - error codes are misfires on 3, 4, 5. Mechanic's initial guesses at the cause are a) vacuum leak, b) bad plug(s), c) bad coil(s). He started the car at the shop and thought it initially sounded a little rough, although it smoothed out after a few seconds. First thing he's gonna do is smoke test it.
So, just a coincidence that this happened soon after getting the IMSB replaced? He's not a noobie at doing them; says he's done 50 or so. If the engine is getting moved around a bit, how hard would it be to break some plastic connector that would result in a vacuum leak?
Not driven again until yesterday...7 miles from home CEL ("drive to workshop") came on. Turned around and took the car home. Took it back to the shop this morning - error codes are misfires on 3, 4, 5. Mechanic's initial guesses at the cause are a) vacuum leak, b) bad plug(s), c) bad coil(s). He started the car at the shop and thought it initially sounded a little rough, although it smoothed out after a few seconds. First thing he's gonna do is smoke test it.
So, just a coincidence that this happened soon after getting the IMSB replaced? He's not a noobie at doing them; says he's done 50 or so. If the engine is getting moved around a bit, how hard would it be to break some plastic connector that would result in a vacuum leak?
06-19-2019, 01:44 PM
#5
How was the weather while sitting? Rainy? How was the weather when the codes popped up? Rainy? Old cracked coils don't like moisture. It is interesting that the CEL didn't show up immediately after the work as you would expect if something went wrong during the work. I would think something would have triggered on the 25 miles home.
06-19-2019, 01:45 PM
#6
Rennlist Member
When I hear "misfires", my immediate reaction is malfunctioning coil packs and/or plugs, but the entire bank#2? Did the shop drop the engine for the IMS and clutch replacement or did they removed any of the plugs for cylinder examinations? Always a chance something got damaged but I would check the lines for the coil packs. Check one step at a time.
06-19-2019, 01:47 PM
#7
When I hear "misfires", my immediate reaction is malfunctioning coil packs and/or plugs, but the entire bank#2? Did the shop drop the engine for the IMS and clutch replacement or did they removed any of the plugs for cylinder examinations? Always a chance something got damaged but I would check the lines for the coil packs. Check one step at a time.
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06-19-2019, 01:54 PM
#9
Since it's bank 2 only, first thing is to read out the "Cam deviation" on both banks. The number should be around 0 degree +/- 6 degrees. It's a bit suspicious after IMSB replacement.
06-19-2019, 02:27 PM
#11
How was the weather while sitting? Rainy? How was the weather when the codes popped up? Rainy? Old cracked coils don't like moisture. It is interesting that the CEL didn't show up immediately after the work as you would expect if something went wrong during the work. I would think something would have triggered on the 25 miles home.
FWIW - the weather was beautiful the entire 900 mile trip home. No moisture.
06-19-2019, 02:30 PM
#12
He's gonna check the timing, but he said you'd have to go out of your way to mess up the timing nowadays when replacing the IMSB.
06-19-2019, 02:34 PM
#13
Rennlist Member
06-19-2019, 02:38 PM
#14