I just got home from a trip. About 250 miles from home I noticed a knock while leaving a toll booth with window down. So I left the radio's turned down and the knock continued.

I called the dealer I bought the truck from at home and he had a couple of suggestions. Check valve lash, he says. The knock is at idle and gets louder and faster with engine speed. The harder the pull the knock gets a little louder.

I got to where I was going and pulled the valve cover and checked the valves, nothing loose. Started engine with Valve cover off and noise sounded like it was in the engine not the rockers.

We removed power from one injector at a time and could not stop the knock. I got home last night and still knocking after fuel and oil treatment from lucas.

I changed the oil tonight. Cut the oil filter open, found no metal. Strained the old oil no metal. The oil had only been in about 2,000 miles. I removed the flywheel converter inspection plate and tried to rule out a broken flexplate. I don't know what else it could be and to be honest don't trust dealers that much when it comes to the engine. I guess I have no choice.

ANY IDEAS?

 

Does the sound change when the TC goes into lockup?
If not I'd think either rod bearing or piston ....

AlpineRAM

 

NO

Does not change from park to neutral either. You can put it in drive and very little differance in sound, if any. Put a load on the engine and the knock gets louder. I dumped the oil as I posted and no metal or trash of any kind in oil filter or drain pan. I am fairly experienced at this technique of finding internal engine failures as I race a Comp elliminater car and occassionally have a cituation that needs to be found out before parts come through the oil pan. LOL.

I can't rule out the flexplate but it is a laminate(double layer) from Suncoast. I would think it would be mighty hard to break. But, this truck shifts overdrive very violently even with stock tranny parts.

 

Did you check the damper on the pulley?

 

Sort of...... I used the damper bolts to turn the engine while checking the torque converter bolts. I did not notice anything wrong with the dampner. I had heard some one had trouble with one.

 

Does the truck still have the same amount of power and run smooth?

 

YES, other than the knock you would not know it had a problem what-so-ever. Local dealer has it now and they are going to pull the engine. I'll be glad to post what they find.

 

I am probably out to lunch, but I can almost bet they find nothing.

I had the same problem with an 01, tore it down to its component parts, and found... nothing. put it back together, no knock. no mechanical reason for the knock to be there, no fueling issues, nothing. Damper was fine as well.

If they do find something, post it for sure, I would be interested to know what it is.