Bad torque converter?

[y5mgisi]

My truck is making this strange knocking noise randomly. It sounds alot like a rod knock but its very random and intermittent. Seems to happen most under a cruise/almost coast condition. Hot or cold doesnt seem to matter. It doesnt do it at idle and it doesnt make a noise on startup in the mornings. The randomness of it makes me think its not actually a rod/main. So maybe torque converter is going south? Thoughts?

 

[KansasTwister]

My truck is making this strange knocking noise randomly. It sounds alot like a rod knock but its very random and intermittent. Seems to happen most under a cruise/almost coast condition. Hot or cold doesnt seem to matter. It doesnt do it at idle and it doesnt make a noise on startup in the mornings. The randomness of it makes me think its not actually a rod/main. So maybe torque converter is going south? Thoughts?

lifter going bad perhaps? when it happens is it fast or slow? crank/driveline i would be hlaf the speed of the valve train noise.

 

[K5dreamer]

motor mount, trans mount, u-joint, rocker arm, valve lash, etc. etc. your best bet is to play around and see if there is a way you can MAKE it act up. then while youve got it sounding off, pop the hood and go hunting.

question, when you HEAR the sound... can you also FEEL the sound? if you can feel it, do you feel it in your hands, your butt, or your feet?

 

[Greg Ducato]

Check your converter bolts first, if they are not loose i would suspect the flywheel is cracked around the crank flange, your symptoms are classic.

 

[y5mgisi]

ifter going bad perhaps? when it happens is it fast or slow? crank/driveline i would be hlaf the speed of the valve train noise.

It seems to happen in the 2000ish RPM range. Sounds alot more like a rod knock then a lifter tick.

question, when you HEAR the sound... can you also FEEL the sound? if you can feel it, do you feel it in your hands, your butt, or your feet?

No i cant feel it. Its just a sound. No noticeable "hicup" if you will.

Check your converter bolts first, if they are not loose i would suspect the flywheel is cracked around the crank flange, your symptoms are classic.

You know i have heard of the flex plates cracking around the centers. Good call. I will check all the bolts and wiggle stuff around.

 

[NorCal_Chris]

my vote for cracked flexplate as well.. almost postive..

 

[USSkoval]

Check your converter bolts first, if they are not loose i would suspect the flywheel is cracked around the crank flange, your symptoms are classic.

X2. With any luck, it's just loose bolts.

 

[y5mgisi]

Ok I will get out there and check that out here before I drive it anymore.