I have a 97 F-150; about 2 years ago I had a new engine installed. This is not a rebuilt engine. There is the history, now this is the problem. After about 6 months of driving with the new engine I developed a miss I took it back to my mechanic he said that water got into one of the spark plugs. He replaced the plugs and said I should change the wires. I?ve changed the wires. It ran fine for about 3 more months. The miss returned. At this point I changed everything including the spark modules. Still about every three months this miss returns I change the plugs (bosch platinum plus) and it runs fine again for about three months. Help
Try it with the stock Mo’craft plugs and see what happens. A LOT of people think these are the best plugs for Fords?
A couple of questions. What engine? Was this a new engine, remanufactured by Ford or rebuilt by someone else?
what do the “bad” plugs look like when you take them out?
it was a new crate engine from ford. 4.6l
they did not look bad for the most part fine
Consider dropping by a local AutoZone, Advance, Checkers, etc. and have the truck scanned. They will do this for you free. Post any results back here for further discussion.
Any chance of posting a good clear pic of of some of the plug tips? If not, are there any faint, blackened areas on the ceramic around the center electrode?
I would strongly advise that with the spark plugs going in and out so much that anti-seize be used on the threads and do NOT overtighten them. JMHO, but overtightening plugs is the likely cause of spark plug thread stripping on these engines. They’re tapered seat, no gasket, so just snug after seat contact is good enough.