I'm stumped... 302 in the ranch- under load sounds like the fans hitting the shroud-

Check the separator plate

 

Check the endplay on your crank.

 

Post what you find.

 

Have a safe trip man. See you when you get here. I will be looking out for the email we talked about earlier

 

I have a 390 FE that was making a similar noise recently.. I was kinda thinking it could’ve been that the flexplate was cracked or maybe the bolts were loose from the torque converter or something...

I took it out and the flexplate wasn’t cracked or loose...There were lots of real fine metal shavings and it looked like the front (crank side) was just barely hitting something...

After looking at the starter some, it looked like the gear might be sticking out a little too far maybe.

I got another starter to compare, and it didn’t seem like it stuck out as far...

So, I put a new starter and flexplate on and the noise was gone...I’ve put about 1400 miles on it since and it still seems to be ok...

 

Yes, to many times the OP never gets back. We all learn from each other expirances.

 

Its up in the air in Brinkers shop-
Tomorrow I'm going to pull the flex plate-
the flexplate wobbles at idle...
pretty sure that the culprit-

Looks like the drain plug for the torq converter doesnt line up with the hole on the flex plate and is pressed up against it. Not sure what thats all about- I'll know more tomorrow.

Doesnt seem to be any starter chatter- all of that looks clean- no metal shavings or signs of contact on the ring gear.
to be continued-

 

"No ****, Sherlock!

 

No **** X 2! and 3!
If this is the case,the flexplate must be wobbling like a MF!

 

Not saying it absolutely could not be the flex plate, but any one I ever changed over the yrs. knocked worse with no load on the motor. If I suspected that was the problem, the first thing I would do is put in gear and hold the brake and load it a little, the sound would usually diminish or go away completely if the plate was cracked.

 

I smushed the bottom tin cover of an automatic into the flexplate on a low car once. Could you have done the same thing? Not sure if C4's have a tin cover similar to a TH350?

 

I'm super curious to see the answer to this. I just refreshed the c6 behind my 352 in my galaxie and it has had a noise similar to what you are describing only when under load. I have checked timing and adjusted valves and done everything everyone I know can think of. My car runs and drives great so I was unconcerned just annoyed by it.

 

I can remember a service bulliten back in the 80's about C4 torque convertors pushing on the trust bearing & wearing it out under power. Also could crack the flex plat under hard excelleration. I have 3 of those cracked flex plates lying against the wall in my garage for people who didn't believe me.

 

My first thought was detonation like Bobwop mentioned, and then I read that the noise started "after a burnout party" which makes the flexplate a more likely suspect.

***uming that the burnout party was burnout in the traditional sense of the word, and not a gathering of the love generation's hippies, beatniks, drop-outs, flower children, freaks and gutter ****s......

 

LMAO Better open your hood and try it. Torque reaction is opposite driveshaft direction.

 

The only way the drain plug would not be lined up with the hole is if it was installed that way or the converter turned on the flex plate.

 

Gotcha that makes sense also

 

Flex plate wasn't cracked.
Replaced it- Adam Brinker and his DAD RULE.
the new flex plate had ob-longed holes for the torque converter drain plug so that bolted up the way it should now...
Looking at the starter again- going to buy a new one just because this one sound like ****- but no sign of anything hitting anything.

it still does the same damn thing. weird as ****... i cant stop thinking about it...

You can do a brake stand and nothing...
rev it up in neutral and nothing...
get in and RUN IT DOWN THE ROAD under LOAD and you hear the noise and it fades away as you get up to speed or let off the gas... its not a "ping" it sounds exactly like bat cable end glancing off a fan blade.

Tomorrow I jerk around with the starter again- and then im done... I'm just gonna head to texas.

I'm totally baffled.

 

Damn.

 

1-When you brake stand as you say, what is the rpm when doing this? 2-There is no load on the engine in nuetral. 3-there is a load with it gear go down the road. So at what rpm compared to brake standing is this happening? Also you never did say how much total timing you have and at what rpm it stops climbing. Three of us here think it's timing related.

 

when in a brake stand under load nothing- not even when you break the wheels free and spin em... not a sound.

when under load going down the road... you can hear it low rpms and it goes away as you get up to speed-
if you take off normal you don't hear it.

it doesn't sound like a ping or detonation... it sounds like something metal hitting the fan blade- exactly like that- like if you had a metal playing card that you taped to your bike so it hit the spokes to make it sound like a motor.

sometimes... when I start it and drop it in gear- it makes it extra loud and sounds like whatever it is is glancing off whatever its hitting and stops and its not even... its like its bouncing off a wall... as if the bat fell into the fan- under NO REAL LOAD. dink da dink dink dink... then quiet.

i replaced the dist last week- moved it both ways and played with the timing. No change at all... i put in a new reman dizzy.

 

just for giggles, dial back the timing and take it for a drive.

it only takes a few seconds and a couple twists of the 9/16" wrench

 

Then if timing is not it, ^^^^^ these would be next. I see your from Hollywood, Ca?. Why I say California, because theres a radio program on Sundays I Listen to thats funny and learning all in one. "The Motor Man Show". Anyways, there was a caller with a Ford van with the issue that you have and Leon had said he's witness bad thrust bearing's do this. Just enough end play so that the flywheel would hit the starter gear. I've went back and read all your posts and I see nothing to tell us if excessive end play is present.

 

Have you tryed removeing the fan belt.

 

Had a similar one. Kind of a clang type noise that came and went ( sometimes continuous ) depending on throttle. I finally chased it down to a tweeked flywheel inspection cover. It actually sounded like it was up front in the fan area.

 

Maybe ya spun a rod bearing doing the burnout, they make some funny noises when that happens. and not always a contsant noise, they can make the noise when theres no load on the motor, and lots of different times, i know the usual idea of a rod knock is all the time but with spun bearings thats not always true.

I really hope thats not what it is as your leaving on a long road trip.

JEFF

 

I may have skipped it, but could it be the water pump bearings are shot? They don't automatically leak as soon as this happens. I know removed the fan, but not sure if you kept the other components. Mine did exactly what you are describing.

 

Something hitting the driveshaft ? Or something loose in or around the exhaust system ?

The exhaust hitting the frame ? Or possibly even an exhaust leak.

Reaching, but this would be driving me nuts.

 

WE FIXED IT!!!

GET THIS...

OK... so... I was thinking about that starter...

The starter looked super close to the flexplate/flywheel whatever you wanna call it- it was super close. I was playing around with the gear on the starter and it pulled out really easy- and decided to replace the starter just because... maybe that gear was moving back when you moved forward- logical right?

OK so the new flywheel is in there and the ob-longed holes fit the torque converter nice- so that got rid of the wobble. It also got rid of a high speed vibration I had.

We figured out the transmission is an 84... while the motor is a 75. so the starter might be different for a 84 trans???

the new starter fixed it-
the gear was sliding back and hitting the ring gear- but so slight and it didnt look like there was any crazy wear or anything!

The new flexplate fixed my vibration problem... (maybe this was the imbalance thing listed above??? not sure) its smooooooth as GL*** on the freeway at high speed. I alwasy thought it was the driveshaft because over the years before me- it had been shortened twice- that vibration drove me nuts too-

HOLY ****... its like driving a new car.

TEXAS HERE I COME------------------------------------------------------->

 

Fantastic ... searching for the cause of one issue and you end up solving two ... enjoy your trip