Hey all, hoping the collective minds on this forum can help with an ongoing misfire issue on my wife's relatively new to us (last summer) 2008 LX 570. 166k miles.
A couple weeks ago, she was backing out of the driveway and felt the car start to shake, CEL came on. Parts store scan indicated P0305 and P0306, misfires on cylinders 5 and 6. Had a mechanic friend of mine come over and replace all 8 plugs, and the ignition coils on 5 and 6.
A day or two later, she was driving it and once again the car started shaking and stumbling, CEL comes back on. This time parts store scan says P0302, cylinder 2 misfire. Couples days later, replace all 6 remaining coils.
She's drives it for a couple days with no issues. However day 3 she starts to notice it misfiring some, but much more subtly and intermittently than before. Misfiring becoming more apparent when under heavier acceleration, with what she described as a "chugging" feeling. No dashboard lights/CEL ever coming on. A few days later I replace the PCV valve because what the hell, why not. Old one was a little gunky but nothing crazy.
It drove pretty good the next day, but the day after resumed the same more subtle yet still misfiring symptoms that were there before the PCV valve replacement. Later that week, we were scheduled to have her car in to a local Indy shop for oil change and were going to have them look into the misfiring issue. I drive it the night before, same subtle misfire/chugging under moderate acceleration. I decide to gun it to see what would happen and boom, flashing CEL, very aggressive misfire the remaining 5 miles home. Next morning, no dashboard lights, drove normal on way to mechanic.
Mechanic cannot recreate CEL, but do notice the misfiring while test driving and say they are able to count misfires on cylinder 2 and only 2. They swap plug/coil with cylinder 4 and the misfire is then present on 4 and only 4. They replace plug and coil on 4. Okay great, maybe just got unlucky with a bad coil. Well...
Drives good for a couple days. Wife reports not noticing any misfiring or chugging. I drive it to pick up kid from day care today, drives great, sweet maybe we've got this thing solved. I give it heavy acceleration getting on the highway and again boom, flashing CEL, aggressive but not quite as aggressive as night before the mechanic misfire. Fortunately I'm right by a parts store. P0305 and P0306 again. Cylinder 5 and 6 misfire. WTF.
Please don't throw anything at me, I did get the Denso coils from Amazon. That said, as a certified novice wannabe mechanic, I am 98.76% sure they are real deal Denso coils. Also, it's way too much of a coincidence that the same 3 cylinders that were reporting misfire issues before, happened to get bad out of the box coils, right? But none of the other 5 did?
Tomorrow I plan to do a side by side of the coil the Indy shop put in with my Amazon Denso coil to see what's what, but I am really doubting that is the issue.
I am hoping someone on here might be able to point me in the direction of what to do next. Or if I am very lucky, my description leads someone to the exact issue. We can dream, right?
Any thoughts or help would be much appreciated!
A couple weeks ago, she was backing out of the driveway and felt the car start to shake, CEL came on. Parts store scan indicated P0305 and P0306, misfires on cylinders 5 and 6. Had a mechanic friend of mine come over and replace all 8 plugs, and the ignition coils on 5 and 6.
A day or two later, she was driving it and once again the car started shaking and stumbling, CEL comes back on. This time parts store scan says P0302, cylinder 2 misfire. Couples days later, replace all 6 remaining coils.
She's drives it for a couple days with no issues. However day 3 she starts to notice it misfiring some, but much more subtly and intermittently than before. Misfiring becoming more apparent when under heavier acceleration, with what she described as a "chugging" feeling. No dashboard lights/CEL ever coming on. A few days later I replace the PCV valve because what the hell, why not. Old one was a little gunky but nothing crazy.
It drove pretty good the next day, but the day after resumed the same more subtle yet still misfiring symptoms that were there before the PCV valve replacement. Later that week, we were scheduled to have her car in to a local Indy shop for oil change and were going to have them look into the misfiring issue. I drive it the night before, same subtle misfire/chugging under moderate acceleration. I decide to gun it to see what would happen and boom, flashing CEL, very aggressive misfire the remaining 5 miles home. Next morning, no dashboard lights, drove normal on way to mechanic.
Mechanic cannot recreate CEL, but do notice the misfiring while test driving and say they are able to count misfires on cylinder 2 and only 2. They swap plug/coil with cylinder 4 and the misfire is then present on 4 and only 4. They replace plug and coil on 4. Okay great, maybe just got unlucky with a bad coil. Well...
Drives good for a couple days. Wife reports not noticing any misfiring or chugging. I drive it to pick up kid from day care today, drives great, sweet maybe we've got this thing solved. I give it heavy acceleration getting on the highway and again boom, flashing CEL, aggressive but not quite as aggressive as night before the mechanic misfire. Fortunately I'm right by a parts store. P0305 and P0306 again. Cylinder 5 and 6 misfire. WTF.
Please don't throw anything at me, I did get the Denso coils from Amazon. That said, as a certified novice wannabe mechanic, I am 98.76% sure they are real deal Denso coils. Also, it's way too much of a coincidence that the same 3 cylinders that were reporting misfire issues before, happened to get bad out of the box coils, right? But none of the other 5 did?
Tomorrow I plan to do a side by side of the coil the Indy shop put in with my Amazon Denso coil to see what's what, but I am really doubting that is the issue.
I am hoping someone on here might be able to point me in the direction of what to do next. Or if I am very lucky, my description leads someone to the exact issue. We can dream, right?
Any thoughts or help would be much appreciated!
