Just installed a sct x3 tuner in a 06 F350 5.4 truck. Noticeable power gains for sure but am worried by what sounds to me like a rattle coming from the timing chain. Wondering what could be the problem or if it is in fact a problem. Should I go back to stock ASAP or do you think I should upgrade the tensioners. Thanks for any help

 

The tuner won't affect it but your foot might a little. It sounds like it needs 2 new chains, 2 tensioners, and 2 guides.

 

Replace the timing set if it has enough oil pressure to operate correctly.

 

Are you sure it's not the cam phasers making noise? It's pretty rare for timing components to go bad on the 5.4's. The issues were addressed in the 4.6 and revised guides were used after 06/03 on all ford models. Unless the truck was very poorly maintained id say you have another issue.

The chains don't need to be replaced, just the guides and tensioners. I have done many of these repairs on 02-03 4.6L v8's. The chains are not marked so if it falls off you will need to take it to ford. You could have an accessory line PS pump or water pump going out which also can explain the noise

How do you know it's timing chain related?

 

I don't know for sure that it is timing sounds that I hear. It sounds like it to me but I am no mechanic. It seems to be mainly when under load but doesn't do it at idle so I'm not sure how to check it exactly. It's got 93,000 on it so it could be a variety o things I suppose. Just odd that its only when the tuner is set to a custom tune and not when it's on the stock program

 

The plastic timing chain tensioners gaskets blow out and lose the oil pressure needed to keep the chains tight and not make the noise slapping against the cover or jumping time. A few teeth jumped and the engine is ruined. The cast iron tensioners are more durable. The chains stretch if not properly maintained. When you see how far the tensioners adjusters are extended you will know chain stretch. Usually the set is replaced.

 

I see that the chains aren't very expensive, how much harder is it to replace them while you are at it on the 6.8 (same as 5.4?).

 

There is no timing marks or TDC indicator on the chains or cam gears. When I worked in a municipal garage we did all in house maintenance. Our instructions were to only replace the chains is wear was seen. If the chains needed replacement the vehicles were taken to Ford.

OP, If the noise is under load it could be a broken exhaust manifold stud, they make many strange noises when there broken. Very rarely would the "seals blow out" of the tensioners. They also have a failsafe spring in them that will take up the slack once the oil pressure fails. 05+ SD trucks with V10's and 5.4's guides are much bigger and more stout then the 4.6L. If you are un sure then take it to a mechanic and have them point you in the right direction. IF the guides are bad The truck was severely neglected and run hard.

Keep in mind the 4.6L will run 24/7 sometimes for many many years under hard police and taxi use. Very rarely was there a failure past 2004. The 5.4 is the same way and there are many that are run hard with no issues.

 

Sounds to me like good ole detonation (Knock), try a tank of premium gas or go back to the stock tune to see if either stops the noise.

 

Savage you may be on to something. Thank you all for the help I'm happy to hear from some of the more seasoned guys here about the reliability of the 5.4 as compared to police and taxi use. Savage you mentioned detonation and I was able to speak to my mechanic this evening and he said the same thing. I'm currently running the 87 tow tune from mike at 5 star. I have about a half a tank of 87 currently but am hesitant to add premium as I was under the impression that I should only run the fuel rated for the tune or vice versa. What are your thoughts on premium w what's currently in the tank and the current tune. Should I run it empty and go back to stock then run premium then try it again. Thanks for the help

 

That is one of the reasons I stopped using my tuner I didn't like the funky noises the motor made when running the tunes, I would agree with the issue being the phazers, the tuner might be trying to advance the timing beyond the phazers capabilitys..

 

Fill up with premium and you'll get mid-grade, running better quality gas won't hurt your engine.

 

It looks like we need to find out what the actual problem is with that truck before speculating.

 

Hard to explain the exact sounds I'm hearing but from what I can tell the only times I hear it is under load when running 87 tow or 87 performance. I do not hear anything unusual when in stock mode and I have not noticed any sound when I'm in 87 economy. I don't know if this helps at all but I know that there has been no adjustments or replacements of timing components thru the life of the truck. Again it's a 2006 with 93,000 on it. Best I should probably have the mechanic take it for a ride with the tunes on which I will do soon.

 

Fill up with premium Shell or BP and comfort yourself.