farupp

I have a 2015 F-150 with the twin turbo 3.5 engine. When I accelerate with a load going up a hill the engine starts to miss and the CEL flashes. The codes are P0300 (engine misfire), P0301, P0302, P0303, ( based on which cylinder is misfiring) etc. The dealer has replaced the all the spark plugs and the defective coil packs in the appropriate cylinders with out solving the problem. In two cases the coil packs have burned up and melted.

The engine has had the oil changed, and air and oil filters replaced. 109,000 miles, 6-speed transmission. 4X4 with locking rear differential, heavy duty tow package, skid plates.

It is going back to the dealer next week for a second time. What should they be looking for as I am not confident they know what is happening.

Thank you.
Frank 2015 F-150 3.5 litre Ecoboost

chimmike

Do yourself a favor and check the spark plug gap yourself. May also be a ground issue if coil packs are burning up and melting.

farupp

Thank you, chimmike. Good points to check.
Frank

southchatham

Fuel injectors? I had to have mine replaced on a 2018. P301 code. It would shake and buck, especially up hill.

farupp

chimmike: I followed your suggestion to check the plug gaps. I went back to the dealer as two more ignition coils were cooked and the truck would barely run on 4 cylinders. I told them I wanted all the old parts. They worked on it for three hours and replaced two more coils under warranty and all the spark plugs, which I told them to check the gap before they installed them. They said they are "pre-gapped" to which I said check them anyway The shock was that all the brand-new spark plugs, installed previously, had huge gaps way over recommended. They said they would replace them at no charge because the gaps initially were wrong and they didn't check them. Truck now runs much better but I can smell another old coil cooking. They never replaced all the old coils which had at least 107,000 mile on them.

Thanks, again, Mike.