OK i'll try to keep this simple.

The engine in my truck has 104k mi. about 6-7 months ago my truck started running badly. It would skip and spudder, use lots of gas, and an overall lack of power. I sensed an ignition problem, changed plugs/wires/cap/rotor..no fix...swapped the coil off my dads truck..no fix...then my tach needle started bouncing irratically (but still sweeps with the motor's RPM until 3k rpm...after 3..the needle of the gauge will push ahead of the engine's RPM by about 300-600+ rpm). I thought it might have been the PIP sensor...couldn't get the old distributor out without breaking a screw...so I replaced the distributor with a new one..timed it...that's good. Checked EGR..02 sensor..fixed vacumm leak...got motor running a little better but not really. Checked spark on cylinders, spark on all but when taking the plug off #8 it didn't change engine RPM. Suspected injectors being clogged up...had all of the right bank's injectors cleaned (don't have the money for all 8, and those are spraying ok, I guess the right side gets more dirt than the left being next to the press reg.). Runs a little better now..not perfect. Next suspect was the cat being clogged...last night I cut the cat out...ran it with no exhaust, just manifolds..for about 3-4 miles...still ran crummy...it idled but also makes a slight pop/poush sound every few seconds. It felt like the pop/poush of air was only coming from the left side of the engine (had it at the y-pipes) and the right side didn't seem like I could feel an extra puff of air at the time it skips.

So I welded the cat back in but hollowed out (still have a 2nd cat in the middle which is only a year old). The cat was not black at all, the honeycomb had a greyish color and it was the original cat. I wasn't able to get good penetration around it, the seams leak a little (planned on bringing it to exhaust shop anyway). Started the truck after putting it together and I now have a rather scary sounding knock from what seems like the left valvetrain. I thought at first it was just the exhaust leaking, but the seams only make puffy noises..no knock...and with the stethescope I could hear it loudly next to the head.

It's a metal knocking sound which taps when the valvetrain comes up and down (same rpm..not a random knock). Using a stethescope (sp) and touching it to various parts with a screwdriver, I listened all around the motor. Nothing abnormal anywhere but the ticking sound is loudest on the left bank's head area. I couldn't pick out a single cylinder with the loudest knock...just the head area. Changed the oil, no metal fillings (still have to cut open the filter though). Proper oil pressure. I'm suspecting a stuck lifter....what do you guys think? I was thinking about taking the valve cover off and inspecting.

 

If you inspect your valve train and find that you have a noisy lifter, or one that is not oiling properly, try this trick I used to save a tear down to replace the lifter: Spray carb cleaner down the pushrod using the plastic tube supplied with the cleaner. Let it set for a while and repeat several times to get the cleaner on/into the lifter. Start the truck and see if the ticking stops. If it continues to tick, use a soft faced lightweight hammer to rap on the pushrod side of the rocker arm while the engine is running. Repeat after a few minutes and do it several times. Use a sharp fast tap, do not beat the rocker arm. I did this on a non oiling lifter and restored oil flow without tearing the top of the engine off to replace the lifter. It may or may not work, but it is easy to do and may save you a bunch of work.

 

Im in Maryland right now..when I get back I plan on taking the valve cover off and checking it out.

Anyone else have any ideas?

 

OK so I had some time to finally wrench on it after my trip. I took the valve cover off, I tried to move all the rockers and check for something broken or loose, nothing. Everything is tight, has proper lubrication it seems (no gunk or sludge, but oiled)...I turned the motor over by hand and all the rockers moved correctly...I have no idea where to go from here so I need some help...anyone?

 

Maybe a cracked manifold?? Prob a long shot but it might be worth lookin into.

 

I was suggested that by another person I called this afternoon. I inspected as best I could with it being on the engine and didn't see any cracks. I leaned away from this idea because the ticking sound wasn't gradual, it was all of a sudden. I have no idea what else to do but to button it up and bring it to the mechanic to see what he thinks.

 

Un plug one plug wire on the side of the engine you hear the knock, start the truck, listen, shut it off, reinstall wire and move to the next wire, remove, start repeat until you have done all four. Did the sound go away or decrease in volume?

 

I'll have to put the engine back together for that one...but I'll do it.

 

OK so I got the mechanic up to my house today. He said it's definitely not a valvetrain noise. He said it's coming more from the outside of the engine's cylinders vs inside (where the pushrods and lifters are) ruiling out the valvetrain. He said it's a small possibility that a chunk of carbon was knocked loose and is banging around in a cylinder...and to try some stuff called "top engine clean" or something like that...I wrote it down...from the Ford dealer. I guess it's suppose to soften the carbon buildups and hopefully get them out. However, he was leaning more towards a broken pin on a piston/rod and that maybe the connection between the rod and the piston is loose and causing the piston to slap. Either way...if the carbon crap doesn't work (which i'm pretty sure it won't but it's worth a shot) the engine will probably be coming out....any comments? basically jus updatin' you guys now...

 

Justin

If you end up having to pull the engine and need a hand, I am a few miles away and willing to help.

Hopefully the carbon stuff will solve the problem but I would think that if a chunk of carbon were bouncing around in there it would have broken up by now.

Good luck.

Ray

 

OK...I willl keep that in mind I really appriciate the offer for help. Whatcha got for experience?

I don't feel that it's a carbon thing either...he didn't feel like it was much of a chance also...but...putting that stuff in the motor isn't gonna be a big deal and I guess it's worth a shot.

 

Doing the plug procedure I mentinoed would give you an idea if it was the rods or main bearings.....have to be one big chunk of carbon huh?

 

Yup...i highly doubt it's a carbon issue. I'll do the plug thing you mentioned when I get a minute, maybe later today.

 

Did it today...not much difference when plug out.

 

Interesting....no difference....according to what little I know that rules out the rods and main bearings. If only we could hear this mystery noise. Screw it, drop the stroker in and forget about it....haha.

What is poush...never heard of that word...you say you feel air?

Wait a second....lemme get this straight...the knock is consistant...does it go away and return at a specific rpm and then go away or continue? I had a knock that would come on at 2000 rpm, anything under it was non existant, any thing over it wanted to quieten with the rpms alittle...in that case it was the main bearing.

What does your oil psi look like during all this?

Good luck