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Your visual perception has limited merit. This is why it is critical on today's EEC OBD2 systems to use scanners and oscilloscopes to perform diagnostics. Also, while the engine idles (hot) and runs at mid levels of throttle, the ECM can and will cover for many problems. Use of a scope along with knowledge of waveform interpretation, coupled with WOT and decel assessments of those wave patterns can and will tell one with dead-on accuracy what's wrong. I recently had a 2002 Chevy pickup with the 6.0L "U" engine with individual coils on each cylinder. It kept setting P0300 "random misfire" DTC's. It also had ambulatory specific cylinder misfires (P0306. P0308. and a couple of others). Pulling out the plugs revealed a .090 air gap! Nearly double spec. Replaced the plugs and got smooth performance...... for a while... Then, the engine started running worse than it had. Broke out the 8 channel scope, and Voila! The front O2 sensors showed voltage bleed over from the heaters to the signal return to the computer, and #6 coil had excessive primary current draw. A new pair of AC Delco front sensors and #6 coil completed the repair.
Guess - copper core good for up to 30K miles
I like the plugs coated in unobtanium!
Ate you hoarding the supply?I like the plugs coated in unobtanium!
Autel comes to mind. I'm partial to the MaxiSys MS906BT. This scanner is about 1200 or so most places, and is capable of coding. It also has fantastic Ford interaction.
They have a full series of tools, I can research one less professional.
I haven't seen any of those yet, just the ones coated with unicorn shizzle.I like the plugs coated in unobtanium!
There is a method to replacing spark plug on the modern truck engines without ever pulling threads or, like the 5.4L fords, breaking them. It requires running a powerful flush through the injectors (BG 201), using a special tool, and then soaking the tops of the plugs overnight with PB Blaster. Since I learned this method over 10 years ago, I never have a broken plug or stripped threads. It requires backing the plugs out about 1/16 to 1/8 turn and soaking them over night with the penetrant AFTER running the flush through the injectors.
I hear tell that they are developing spark plugs worthy of turbo encapsulator duty!
As a stand alone cure, no, the injector flush doesn't do the trick.... I've tried that and had it fail. Further research revealed that the injector flush, using a VERY potent chemical (My stuff will remove paint from the fender if it drips onto it), will effectively remove carbon from the nose and lead threads of the plug/head mating area. That is merely step ONE. The action of cranking the plugs back off the seat 1/16 to 1/8 turn allows PB blaster to soak from the top overnight. These TWO steps done in combination, along with proper turning procedure have worked 100% of the time in the past 10 years for me since I began doing it that way.
