Rteas48134

I have a 2007 F-150, I replaced the motor with a brand new crate 5.4 (lost a main bearing shim and lost pressure at 130K on the old one) the new motor has less than 2K miles on it. I first noticed it when in reverse backing up a trailer i have this Knocking / Dieseling. I unhooked the trailer and with the truck in reverse foot on the brake turning the steering wheel back and forth it sounds like the motor is knocking. I cannot get it to replicate in any other scenario except that. Whats the deal? Brand new engine (Crate motor now has 2K miles)

Eric Kleven

All I got is: if it's only doing this if the motor is up to temp, & if you're running 5w-20, try going up a weight. 5w-30 might stabilize things.

Chris James

So... Did it work?

MCpllabelle

Yup...7 hours later it worked like a charm!

Eric Kleven

Only 7? Took me 30.... hehehe

MCpllabelle

Yup lol!!! A whole 7 hours.

corpsman69

I'm having thesame issue this only happens when reversing my 27' travel trailer, new crate motor, started with 5W-20, went to 5W30 and still having same issue. checked spark plugs and they are new and clean and gapped apporpriately. I only have 800 miles on motor. recent change of trans filter and transmission fluids to include torgue converter flush with ford motorcraft transmission fluid ( fluid at normal levels in trans and in engine oil). Funny part is this did exactly same thing with prior engine and same transmission, truck is 2007 f150 fx4 with 96654 miles on it. any help would be appreciated, thanks. This does not happen when I have towed other trailers and backed them up.

Justinmur