Hi I have a 1999 f150 5.4 4x4 xlt with 150.000 miles.

The problem I've been having is a knock coming from near the bellhousing only at idle after about 1000rmps gone and does get quieter after normal operation temperature. No noise going down the road, no loss of power, no miss fires, no codes, no loss of oil. I've changed the oil with mobil 1 5w30 and motorcraft filter. I've replaced both cats one manifold, spark plugs.

Things I've tried

Unplugged each coil listing for a change nothing changed

Replaced both cats nothing changed

Replaced right manifold got rid of the exhaust leak. But still knocks

Tested oil prussure good cold good hot.

No metal shavings in oil changed it 3 times in the last 5000 miles checking.

I'm totally lost with this truck. Should of just bought a truck with the 5.0 lol

And to add the knock never changes it sounds the same in the morning and the same once warm.

Thanks Joe

 

Welcome to the Connecticut sight and Ford Enthusiasts. I'm just plain nosy. What's your name (should put it in the signature at bottom) Are you from Connecticut? I don't have the answer to your knocking but I am sure someone here will give you the info you need. you will find a good group of guy's with a lot of answers.

Again welcome to the forum.

john

 

Thanks for having me. And yes I'm from Connecticut. I have been told it was a torque converter problem or flex plate. But that's a big job I want to know for sure that's the problem before I tear it all apart.

Joe

 

Good chance it is a failing flex plate.