Hi guys.

Recently installed a pi 5.4 in my truck, from a non-pi 5.4. Ran and sounded great when I first started it and let it idle to temp. Killed it to tighten everything up for a trip down the road, and when I started it again, it was knocking. I took a video of the knock. Truck doesn't seem to run any worse, and the knock hasn't gotten any worse. I'm worried it's a rod knock.

Knock-
Any sure fire ways to tell? Any suggestions?

Thanks guys,

 

Any ideas guys. Should I just chock it up to a rod bearing, or are there other things that commonly fair on these engines that cause knocks. Engine is an 04 5.4 out of an Expedition.

 

2 valve? Piston slap, dry starts due to use of a substandard oil filter, cam followers.

 

Yes, it's a 2 valve. Only use motorcraft filters.

Piston slap sounds pretty bad. What would cause that?

Can followers? Please elaborate if you can

 

5.4's are noted for piston slap. Old thread, but this describes it:

https://www.f150online.com/forums/v8...n-summary.html

Cam followers = fingers (what you would call rocker arms on a pushrod motor) and what you would call lifters on pushrod motors.

 

Well I'm going to go out on a limb with this but I don't think its piston slap or a rod knock. It sounds more like an exhaust issue to me. Both a rod knock and piston slap are much more defined than what I am hearing on your audio. My hearing is pretty bad however from listening to way to many engines over the years. I just have a gut feeling here that its more exhaust system related than an engine component noise. Use a mechanics stethoscope to determine exact area of the noise.JMO.

 

Appreciate the comment, but I can assure you, it's not an exhaust issue. It's internal somewhere, I just haven't had time to tear it down and find out exactly where. Hopefully I will have time this weekend to do whatever needs to be done, to get it back on the road.

I'm just hoping it doesn't need a rebuild.

 

Ok I have been listening to this about 15 times this morning while everyone is sleeping and I can hear the noise better and it sounds like you do have something going on. That hollow sound when you first went below sounded like exhaust to me however I think I am wrong about that. Start disconnecting injectors while its running one at a time and listen for the noise to diminish on any one of the cyls. That is a good way to determine a rod knock and on a particular cyl. The stethoscope works very well also Harbor freight has them for 5 bucks and they work good. It sounds like first order which is base engine, second order is valve train. Is it only during cold running or is it after warmup. Sometimes with a piston slap the noise diminishes or goes away after the piston gets warm and changes dimension. What is the history on this engine you just installed, how many miles on it etc. Get a stethoscope and listen at the oil pan, front cover, exhaust manifolds etc. to locate as close as possible the location of the noise. That will help you determine the root cause.

 

Power brake the motor in gear and see if the noise changes, could be a loose flex plate bolts or torque convertor bolts??? If none talked about in the above posts.