My truck has a Gremlin!!!

[PropMan]

I am lost trying to find this squeak/chirp Gremlin. Any help is appreciated!

Back story-
I have a 72 K2500 that had a 350/350/NP205. I pulled the engine and trans and installed a Blueprint 373HP small block and a K case 700r4. I moved the engine forward approx 1.75 inches to comp for the extra trans length, had the proper shaft made for the 700 to 205 interface. It runs Awesome and with 410 gears i get 14 mpg @ 70 mph.

My problem- after about 12 minutes of running a squeak/chirp starts, it is the loudest under the engine at the rear main.

Video of the gremlin https://youtu.be/Hg4CyTlW8XI

So far-
1-replaced the torque converter-B&M bad out of the box-was making a moaning sound
2-replaced the B&M flexplate-miss drilled bolt holes-causing binding when heated up
3-had the trans checked twice-on one occasion cracked a mounting hole-my fault-had all innards swapped into new case
4-Blueprint sent new rockers-replaced them-apparently they had a bad batch
5-checked every bolt/nut under the truck TWICE
6-Disconnected the converter and ran it- still makes the noise
7-sprayed carb cleaner around intake and base of carb to see if any change
8-cut the oil filter and inspected for metal- all clear


My next thought is it's possibly in the distributor, gonna swap that soon as i can

[mongocanfly]

Wow..that sounds awful..sure sounds like something rubbing..almost like flexplate is rubbing something

[PropMan]

I forgot to add- at an idle below 700rpm it is normal- no noise

No visible signs of contact on the flexplate either

[mongocanfly]

My next thought would be the oil pump...do you have a stethoscope?...grab one from cardboard freight if you dont...or use a big screwdriver to you ear..might help narrow down where to look

[cadillac_al]

I don't recognize that noise. I thought it got louder near the trans but you already ruled that out. I think you are on the right track with distributor/oil pump/ rear main bearing area. Some distributors don't seem to drop low enough on the intake manifold. I have done the 2 or 3 gasket trick to take up the slack. I'm wondering if your distributor is clamped down too tight and squeezing the oil pump.

[PropMan]

I've got a stethoscope, no luck there. going to look at the distributor for signs of wear and try the extra gasket cadillac_al suggested. Thanks

[kwmech]

I've seen dry seals make that noise. Rear main or trans input. Unbolt the torque convertor, slide it back and start the engine when it does that.

[PropMan]

Originally Posted by kwmech

I've seen dry seals make that noise. Rear main or trans input. Unbolt the torque convertor, slide it back and start the engine when it does that.

Yes, Done that, noise is still there. It's most present at rear of engine by the oil pan.

[geezer#99]

Loosen the distributor, slip a couple 1/8 inch shims opposite each other under the flange.
Snug it back up and test for noise.

[PropMan]

Shimming up the distributor fixed it!

thanks for y'alls input.

[mongocanfly]

Good deal