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Heres my problem i have a 04 superduty 5.4 2 valve motor. When i start it in the morning has it normal rattles then about 30 seconds it gets nice and quite. Then about 5 mins into it it starts to knock. I narrowed it down to passenger side of motor towards the front but not sure if its piston or what. Pulled the wires of the coil to try to pinpoint which cyl didn't make a difference. The weird thing is sometimes the noise is louder sometimes it quiet not that you can't here it. Any body else have this problem am i just worry about nothing? Just makes alot of noise for a 70,000 mile motor. We took a stethoscope and found the noise under the intake but now is it just carrying from valve train. Could this be a lifter or rocker arm. One more thing the truck only does this at an idle and maybe 300 rpms above idle. Bottom end is totally quite. Very frustrate with this one even took it to ford and they said its normal but it didn't start doing it until 3 month ago.
You really have to check the oil pressure with a mechanical gauge.
This does NOT SOUND GOOD. I wouldn't drive it until you figure out exactly what it is.
It could be the oil filter bypass valve is not sealing, it could be the bypass valve in the oil pump is stuck open, it could be a lot of things.
That "knock", does it get loud when you get on it, or does it never change volume? If it gets louder when you get on it, it's a rod knock or something related. If it doesn't change volume, it could be a valve chain slapping, or a cam journal is shot.
the knocking sound goes away when i get on it. Its only there at an idle. And it not the same volume all the time sometimes it louder then other times. But its always at an idle. No noise whatsoever driving down the road until you come to a stop and it idles down again.
Sometimes an exhaust leak at the intake or exhaust manifold can mimick a noisy lifter noise. Go over it thoroughly again with the scope or if easier try a 3'-4' length of 1/4"od or similar tubing and put in one ear.
Well i'm taking a shot in the dark and gonna replace the lifters. I'll start there first. Just seems to me if it were a piston it would be the same volume all the time and would do it when you rev it up. The valve train does rattle when you first start it up in the morning. Maybe i'll find a bad rocker arm or something.
You really have to check the oil pressure with a mechanical gauge.
This does NOT SOUND GOOD. I wouldn't drive it until you figure out exactly what it is.
It could be the oil filter bypass valve is not sealing, it could be the bypass valve in the oil pump is stuck open, it could be a lot of things.
That "knock", does it get loud when you get on it, or does it never change volume? If it gets louder when you get on it, it's a rod knock or something related. If it doesn't change volume, it could be a valve chain slapping, or a cam journal is shot.
bottom end is quite no noise whatsoever under the truck
Sometimes an exhaust leak at the intake or exhaust manifold can mimick a noisy lifter noise. Go over it thoroughly again with the scope or if easier try a 3'-4' length of 1/4"od or similar tubing and put in one ear.
Yeah, didn't even think about that. Pretty common to have a broken stud.
Well this is what i found out tonight. Found a loose spark plug on right side around the same spot we heard the noise. Changed the plug still have the noise did some checking around and what i'm finding out is with a loose plug it draws in unwanted air which makes the o2 sensors richin the cyl up and i get excess carbon build up. So i got a carbon knock. The old spark plug was all black like it was real rich. So now i guess i'll get some seafoam and see if i can get it decarbed.