Mattyhooks
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- Dec 31, 2019
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Hello, I am currently seeking some guidance or insight my truck.
Problem- Rough idle at cold and warm start, in neutral, drive, pretty much all the time. RPMs typically start between 700-1500, then after a few seconds down to 500. Currently, shaking occurs at all RPMs. Sometimes it holds 700 or 1000 or 1500, but will shake throughout. MPG typically range from 16-20 and haven't changed much. I may have messed up by running 87 Octane Top Tier until 36K miles. The rough idle issue began right around 30K and it didn't seem that bad. At 36K, I had cylinder #5 misfire. I changed the sparkplug and rotated around coil packs and still no fix. I got it to the dealership, they recommended a fuel system flush/clean, which they performed, and switching to 89 Octane. Since that visit, I have ran nothing but 93 Octane Top Tier. Next day, Idle rpms are around 1500 and smooth. Driving normal, then CEL pops on, and cylinder #4 misfire and P0441 evap leak. Due to service availability, dealership looked at it about a week later, but the codes went away before they looked at it. Obviously they couldn't determine the problem, but did an engine combustion CPU update. Seem fine for a few days idling between 700 and 1500 RPM no shaking. Shaking returns, low RPM and P0441 code returns. At this point, no noticeable MPG or power loss. Return to the dealership, they find a cracked hose and replace. Few days after code has not returned, but idle seems iffy. A few weeks go by and now idle is constantly at 500 RPM and shakes. Sometimes shaking is more violent than others.
Could this issue be the result of running 87 Octane? The misfires indicate a fuel injector problem. It appears every time the dealership looks at it, the rough idle problem is fixed for a short time period, then returns. It makes me wonder what they are they doing /not doing. What are your thoughts? Iwill gladly take any advice.
Thanks in advance!
Problem- Rough idle at cold and warm start, in neutral, drive, pretty much all the time. RPMs typically start between 700-1500, then after a few seconds down to 500. Currently, shaking occurs at all RPMs. Sometimes it holds 700 or 1000 or 1500, but will shake throughout. MPG typically range from 16-20 and haven't changed much. I may have messed up by running 87 Octane Top Tier until 36K miles. The rough idle issue began right around 30K and it didn't seem that bad. At 36K, I had cylinder #5 misfire. I changed the sparkplug and rotated around coil packs and still no fix. I got it to the dealership, they recommended a fuel system flush/clean, which they performed, and switching to 89 Octane. Since that visit, I have ran nothing but 93 Octane Top Tier. Next day, Idle rpms are around 1500 and smooth. Driving normal, then CEL pops on, and cylinder #4 misfire and P0441 evap leak. Due to service availability, dealership looked at it about a week later, but the codes went away before they looked at it. Obviously they couldn't determine the problem, but did an engine combustion CPU update. Seem fine for a few days idling between 700 and 1500 RPM no shaking. Shaking returns, low RPM and P0441 code returns. At this point, no noticeable MPG or power loss. Return to the dealership, they find a cracked hose and replace. Few days after code has not returned, but idle seems iffy. A few weeks go by and now idle is constantly at 500 RPM and shakes. Sometimes shaking is more violent than others.
Could this issue be the result of running 87 Octane? The misfires indicate a fuel injector problem. It appears every time the dealership looks at it, the rough idle problem is fixed for a short time period, then returns. It makes me wonder what they are they doing /not doing. What are your thoughts? Iwill gladly take any advice.
Thanks in advance!