zachyfarms

I have 5.4l that i have had for a month that i got at ford dealer. Has 50k on f150 fx4. I have watched every video on you tube and read a lot of posts here. none sound or seem like my issue It could have been discussed here but i need some ideas. the knock is in low rpm like 1000 and below knock. It is definately rotational as in knocks at the speed of the engine rotating i read about phasers and all the top end stuff and its not that. It is coming from somewhere on passenger side of the engine from exhaust man and down to the cat area.somewhere in there. No noise is at top of engine area. the knock comes and goes as it pleases but is only when truck is warm. I listened around with stethescope and the cat is not making the noise nor is it coming from oil pan area. the noise is loud at times and can hear it in car other times very quiet. i cant get in close past oil pan to listen. Does any one know what would commonly start knocking/tapping in this area. I am trying to get audio/video of noise but the truck knows when i am filming some how and wont make the noise. thank you for your help

lx4life

that sounds like my issue to after replacing my cam phaser

stich04

i was told it could be a wrist pin

Buell25RR

Try holding the brake with it in gear and the engine warm and rev to just under 1k for a min or so, then let off the gas. See if you can replicate it that way. Thats how I could replicate mine knocking.

zachyfarms

buell did you get this problem fixed? I can replicate at about 1k somewhere but it is an intermittent knock at idle. comes and goes. what was the cause of your tapping.

for added info. the tapping or knock under load at 1k starts to be more of a fluttering knock and the tap at idle has same tone or pitch but is a very distinct clear tap tap tap and stays at same tempo. some times if i touch the gas and as it comes back to idle the sound is gone for a little while then comes back.

I am concerned of the wrist pin issue as well. i was going to just replace HLAs until i heard of the wrist pin being possible prob.

Buell25RR

As mine is under warranty I took it in and showed the dealer how I could replicate it. They checked the oil pressure when the engine was making noise. They said it needs 25psi min for the vcts to work and I had 18-30 while it was making noise. Plus mine was a full blown knock. It was only running on 4 cylinders. It was shaking like it had huge cams in it.

So they tore down the engine, they found both cams had lots of wear and the oil pump had visible wear. They ordered mine a new long block and have started to put it back together now.

My truck is an 07 xlt with 44k.

zachyfarms

WOW!! Yeah mine does not bounce around or shake bad. I have a rough idle but i am leaning towards spark plugs for that.....

NEW CLUE.. with stethescope i can only hear tapping through the exhaust system. no where else on engine has the tapping sound.. whould that mean bad valves.. I am guessing it would have to be something near the exhaust man causing the tapping for it to be heard through that system right.. any ideas please

Buell25RR

Have you checked the manifolds for cracks?

gpreeves37

The maechanics that I use found the cause of my knock. It was the exhaust converter. It is just before the catalytic converter. They cut it off and welded a straight pipe to the CV. The exhaust converter rattled just like the noise I was hearing from the engine. I no longer have a knock or pinging noise, no longer have a shaking in the steering wheel, or sluggish feel at top end. They have ordered another part to replace the one they cut off, but it is $500. good news it wasn't cam phaser.

reallyniceguy915

well..now I find this thread lol mine has same problem. was the converters