How do you find a spun rod bearing?

[MalcolmV8]

I finished closing up the bottom of the motor, put the kmember and all suspension back.
I pulled the transmission. Fired it up (super charger belt pulled to eliminate that). The noise was at the bottom of the motor as always. It really sounded like it was in the back by the flywheel and clutch. So I pulled the exhaust, pulled the bell housing and clutch. The clutch looks fine. I shook the clutch disk and it might have a little rattle but doesn't seem like it could be causing the noise I hear. Flywheel bolts are all still in place and seem fine.

Humm suppose I could put the bell housing back and starter motor and fire it up like that with no clutch and see if it's any different.

[v8ranger]

WOW!!!!! I realy figured it would have been back there too.

[Warpig Racing]

So without the clutch in, it wont spin the transmission orthe clutch. if noise is still there than you have narrowed it to the engine.

[MalcolmV8]

OK fired up the motor without the clutch. It's clearly coming from the engine. I got a stethoscope today too and the noise was very hard to trace. On the oil pan I can hear it lightly. On the valve covers not really. On the supercharger yes but that's because it's aluminum and it's resonating up through it. The supercharger's belt is removed. On the bell housing yes I can hear it real loud and clear. Once again I'm certain because it's aluminum and carrying sound very well.

Then my first real clue. I can hear the sound in the passenger's side exhaust but not the driver's side. I tried getting to the header and cylinder block as much as I could on the passenger's side and that's where it seems to be more so than the driver's side. So either a piston or lash adjuster or something on the passenger's side of the motor.

Here's another video

http://www.youtube.com/watch?v=UrG3cb5EHR8

[Warpig Racing]

malcolm.. does this engine have the roller lifters that are attached by the rail? Is it possible that one of those broke?

that valve cover seemed fairly easy to get to. Might as well pull it off and take a look.

When you had the pan off, did you find any metal?

[MalcolmV8]

Not familiar with the valve train on these 4.6 mod motors but I will probably pull that passenger's side valve cover next.
No metal shavings in pan. I saved the oil filter from that oil change too, will see about getting it opened up and see inside for any metal shavings.

[Warpig Racing]

i just recalled something. When i had busted lifters and cam issues, the mechanic said that he identified the problem with a heat gun on the headers. If you have one of these heat guns, fire it up and let it get warm and check the temp on each exhaust port. If one is significantly colder then the others, would indicate that there was a valve or cam issue on that cyclinder and not allowing the fresh gases in. If it was an exhaust lifter or cam issue not opening, it would be back firing like crazy.

[MalcolmV8]

Sounds like a good idea but I can barely even see the exhaust manifold, let alone point a temp gun at it. In fact I couldn't even get line of sight to get the stethoscope on there today. I was hoping to isolate the noisy cylinder with it but lack of access prevented that.

[v8ranger]

I had suggested that you use a heat gun a few pages ago. I think thats going to be your best bet at this point to try and find your problem. Or just start pulling valve covers. I hate tracking down noises, they never seam to be what you thought, lol.

[88ranger306]

Very odd that there is no metal shavings in the pan after running the engine with such a noise. My friend bought an 01 lightning a few years back with 22k miles on it and a few thousand miles later after he drained the diesel oil out of it, the spun rod bearing knocked like no tomorrow. Luckily with the extended warrenty ford put a new gt500 shortblock in it. (Moral of the story is the previous owner had it heavily modified, and proceeded to beat the crap out of it. After it spun a bearing that is when the ridiculously thick oil was put in to eliminate the knock.)

[MalcolmV8]

When cylinder number 3s piston was all the way down the outside of the piston skirt had a shiny silver and a darker grey. I ran my finger over it and I could feel the difference.

To quote myself from back when I first pulled the oil pan - I wonder if it's piston # 3 that's damaged and that's piston slap I hear. The noise is on the passenger's side.

[v8ranger]

I would pull the valve cover on that side first, and start it up, if you can, to see if all is moving the way its supose to. Sounds like you might be pulling the engine apart to find a bad piston or wrist pin. yuck!!!!

[Warpig Racing]

any update?

[MalcolmV8]

Not yet, it'll still be a few more days before I make it out to the garage to work on it some more. I think next the passenger's valve cover comes off.

[rojam18801]

you got to find that noise soon. i'm going nut's here waiting! maybe i'll have to go up there and pull it apart. lol. oh i didnt tell you guy's, big truck went down, out of work. got coolent in the oil. not known what broke yet. i do know it will cost between $1200.00 and $7000.00. and me with no money. got to beg for a loan. the company i lease to said they will pop me a loan. or this is a big site, everyone could send me a dime. lol. i'll have lot's of time to tinker with little ranger now....the old trucker