misfire no code
#1
misfire no code
Hi All,
I have a 2008 F150 4x4, 4.6 with around 165,000 miles. I replaced coils, boots and plugs around 120,000 miles.
I am getting a misfire at 45 to 65 mph and it seems like it is getting worse but will not throw a code. I took my truck to the dealer yesterday and had them perform a diagnostic scan. Their scan showed an intermittent misfire but could not determine which cylinder. Their diagnosis was a leak in the intake, causing a coolant leak which was causing the misfire and they would need to replace the intake, gasket, plugs, boots, thermostat and other small stuff for $1300.
I have read through many of the misfire threads and never heard of this problem. I have dealt with coil problems before but would get a code which made for an easy diagnosis and repair. Without a code this is beyond my level of experience.
Any recommendations or suggestions would be greatly appreciated.
I have a 2008 F150 4x4, 4.6 with around 165,000 miles. I replaced coils, boots and plugs around 120,000 miles.
I am getting a misfire at 45 to 65 mph and it seems like it is getting worse but will not throw a code. I took my truck to the dealer yesterday and had them perform a diagnostic scan. Their scan showed an intermittent misfire but could not determine which cylinder. Their diagnosis was a leak in the intake, causing a coolant leak which was causing the misfire and they would need to replace the intake, gasket, plugs, boots, thermostat and other small stuff for $1300.
I have read through many of the misfire threads and never heard of this problem. I have dealt with coil problems before but would get a code which made for an easy diagnosis and repair. Without a code this is beyond my level of experience.
Any recommendations or suggestions would be greatly appreciated.
#3
I wanted to give quick update. After I left the dealer Tuesday I went home and took my air filter out and put in another one that I had, I have a couple of different cleanable filters, and also cleaned the M.A.S. and did a visual inspection on the top of the engine looking for any leaks. My truck still had the misfire when I drove to work yesterday morning and figured I would have to try to chase down the problem with a coil, boots or plugs this coming weekend. well when I drove home yesterday the truck drove perfectly, apparently cleaning the M.A.S. and giving the computer time to reset itself resolved the problem. When I got home I got up on the engine with a good flashlight checking once again for any visible leak, since that was the diagnosis that I got from the dealer, I cant find any sign of leakage. I wonder if the guy that did the diagnosis just did not want to bother with tracking down the problem and figured he would go for a big ticket fix.