08' 5.4 3v periodic knock at low idle - video

burndout · #1 02-04-2012, 05:58 PM

Bought this truck used less than a month ago, 74K on the clock.
About a week ago it developed a low rpm knock that only stays for a few seconds. It got worse soon after. I know the video is crap but its all I got. Anyone have any ideas what could cause this? Today I did an oil and filter change and an air filter. Now it dies when this happens. HELP!

http://www.youtube.com/watch?v=JmzEt...ature=youtu.be

swazo · #2 02-04-2012, 06:31 PM

The video isn't working, but I would say it's your cam phasers. I'm having a new engine installed as we speak because of something like this. Randomly it just started to knock when idling and would drop the RPMs in half, but would clear up when you'd give it a little gas. The CEL eventually came on and back to the dealership mine went.

Any warranty at all? Even a 30 day stealership guarantee?

burndout · #3 02-04-2012, 10:47 PM

http://www.youtube.com/watch?feature...&v=JmzEt2TTq7Y

Maybe that will work, im a first time youtube user.

Ive listened to ALOT of videos and read tons of posts and the issue I am having seems different. How long did it take your CEL to come on? Why not just replace the phasers? Did it damage the motor?

swazo · #4 02-05-2012, 12:32 PM

I hit some major traffic on the freeway, and the engine started to idle rough (dropped in RPMS and was making the same kind of noise yours is on the video). I was worried it was going to die, but if I'd give it enough gas to get back up closer to 1K rpms, it would smooth out. I dealt with this for a half hour of 5 mph max, stop and go California style traffic. Once I got off the freeway, I stopped at a gas station to see what was going on, and it was doing it pretty badly at that point and the CEL came on.

I had my truck towed to the Dealership, and they said it was the cam phasers and the chain tensioners. The timing chain tensioners supposedly have a seal that some seem to disolve, which cause an internal leak where the top end of the engine is starving for oil.
They quoted 1300 in parts, 1900 in labor to repair that engine. That was a best case situation, since the chain guides can get chewed up and other associated components, sending metal shaving throughout the engine, depending on how long the truck has been running that way. That could also mean it's time for a new engine, since it's more expensive (according to the Service Manager) to rebuild and cheaper to replace.

Mine is covered under an insurance claim, or I'd be in the same boat as you seem to be.

burndout · #5 02-05-2012, 03:13 PM

how was this covered in an insurance claim?

Quote:

Originally Posted by swazo

I hit some major traffic on the freeway, and the engine started to idle rough (dropped in RPMS and was making the same kind of noise yours is on the video). I was worried it was going to die, but if I'd give it enough gas to get back up closer to 1K rpms, it would smooth out. I dealt with this for a half hour of 5 mph max, stop and go California style traffic. Once I got off the freeway, I stopped at a gas station to see what was going on, and it was doing it pretty badly at that point and the CEL came on.

I had my truck towed to the Dealership, and they said it was the cam phasers and the chain tensioners. The timing chain tensioners supposedly have a seal that some seem to disolve, which cause an internal leak where the top end of the engine is starving for oil.
They quoted 1300 in parts, 1900 in labor to repair that engine. That was a best case situation, since the chain guides can get chewed up and other associated components, sending metal shaving throughout the engine, depending on how long the truck has been running that way. That could also mean it's time for a new engine, since it's more expensive (according to the Service Manager) to rebuild and cheaper to replace.

Mine is covered under an insurance claim, or I'd be in the same boat as you seem to be.

burndout · #6 02-05-2012, 04:32 PM

Found something quiet intresting, locks that are installed in the phaser to not allow movement, either fully advanced or fully retarded. I may look into this, hell, if it means a fix for 50$ that I can do in my own garage AND the thought of no future issues, I am on board. It does say a it will need to be tunned but 50 for the lockouts and a few hunder for a tune... cheaper than the price of one replacment phaser.
http://www.livernoismotorsports.com/...-Lockouts.html

Toyz · #7 02-05-2012, 04:35 PM

Wish I could help. Don't know much about the 3v's. But I will say, that does not sound good.

swazo · #8 02-05-2012, 05:45 PM

Quote:

Originally Posted by burndout

how was this covered in an insurance claim?

My truck was in an accident, the engine had a hole in the oil pan and the collision shop started it up and threw a rod. The POS engine they installed had 60K and had a lot of problems. Now it's at the dealership this time around and they're installing a reman.

swazo · #9 02-05-2012, 05:47 PM

Quote:

Originally Posted by burndout

Found something quiet intresting, locks that are installed in the phaser to not allow movement, either fully advanced or fully retarded. I may look into this, hell, if it means a fix for 50$ that I can do in my own garage AND the thought of no future issues, I am on board. It does say a it will need to be tunned but 50 for the lockouts and a few hunder for a tune... cheaper than the price of one replacment phaser.
http://www.livernoismotorsports.com/...-Lockouts.html

It will kill some of the tq and hp. They recommend using them when adding forced induction so the loss isn't noticeable

burndout · #10 02-05-2012, 09:37 PM

Quote:

Originally Posted by swazo

It will kill some of the tq and hp. They recommend using them when adding forced induction so the loss isn't noticeable

I agree that some HP would be lost, but at the full advanced it would only be up high, 5k+. This truck will not be seeing anything that high. As for tq, fully advanced I would think would be equal if not more as fully advanced would bring on the torque "setting" of the VCT, once the RPM's come up it would begin to retard the timing to help with the big end, I'm no tuner nor do I have personal exp with pcm tunes etc but think this would be correct.

Look at it like this, drag cars run the timing retarded because of the use of either a big stall or dumping the clutch off the line, there for the motor always stays up high and needing the timing retarded. On the other hand to put down high torque numbers the timing gets bumped to increase low end.

Again, not a tuner by any means but I dont think I would be loosing anything by adding the lockouts and having the PCM flashed, certainly not loosing out on the money it would cost to replace the phasers every 30-70k.

Anyone have any thoughts on this? If my thinking is incorrect feel free to let me know, I'm trying to make an educated/good for the future decision here, thanks!

Also to note on the Livernois site and multiple posts on the modular mustangs forums they (Livernois) specifically state that the lockouts were not designed for the use of adding bigger cams, they were primarily designed to help with what Ford refused to address. Now that doesnt mean that they would be required when adding a bigger cam.