Motor rattle after shifting?

[747mopar]

Just this week I've developed a strange rattle in my motor. It runs perfect, makes no noise and has good oil pressure but whenever you run it up to 6,000rpm it will rattle for a couple seconds right after you shift when the rpms are broought back down. Since I have a solid lift cam and it sounds like a loose pushrod I went threw and readjusted them all but the noise persist. I'm not rolling out maybe a loose converter or anything else but so I thought before I get back to the garage I'd gather some possibilties from you guys. I'll be pulling the motor to fit a new bellhousing and tranny anyways so it's not going to be a big deal to dig into. Thanks

 

[cdr]

back your timing up a couple of deg

 

[bigmanjbmopar]

bad lifter? bearings on the rollers? Is it just a sound or do you feel the whole car shake?

 

[furyus]

back your timing up a couple of deg

X2

 

[Cranky]

At what RPM are you hearing the rattle? Does it sound like pinging? Generally pinging under load happens in the lower rpm ranges and you won't hear it in the upper ranges because there's not enough time for the engine to ping. Pinging is caused by a 2nd flame front colliding with the first one that's created by the spark. Now you might be hearing pre-ignition which is cased by carbon or something else that is hot enough to light off the fuel/air charge before the spark plug has a chance to do it. Does the engine run on after you turn off the key? Both can and will cause damage but imo, pre-ignition is worse. With that said, does the rattle sound mechanical?

 

[747mopar]

back your timing up a couple of deg

Easy enough to try, I'll try it tonight. Thanks

- - - Updated - - -

At what RPM are you hearing the rattle? Does it sound like pinging? Generally pinging under load happens in the lower rpm ranges and you won't hear it in the upper ranges because there's not enough time for the engine to ping. Pinging is caused by a 2nd flame front colliding with the first one that's created by the spark. Now you might be hearing pre-ignition which is cased by carbon or something else that is hot enough to light off the fuel/air charge before the spark plug has a chance to do it. Does the engine run on after you turn off the key? Both can and will cause damage but imo, pre-ignition is worse. With that said, does the rattle sound mechanical?

I didn't catch what the rpms were but it was directly after shifting into second from 6,000 rpm. I've heard pinging before and I don't think this is pinging plus it doesn't do it under load just after a high rpm shift. The motor runs perectly in every other way, no run on or anything else but the timing has been nothing but a pain in my ***. I've tried several adv curves but this motor likes to be advanced right off the bat to 36 and stay there but if I take it down to 20 at idle it's a dog off the line?

- - - Updated - - -

I'm currious as to why the timing would make this noise and if it is the timing why it just started doing it out of the blue?

- - - Updated - - -

bad lifter? bearings on the rollers? Is it just a sound or do you feel the whole car shake?

Just a sound, can't feel any difference. I was wondering about the roller rocker tips? Lfters are solid lifters.

 

[benno440]

i had that same rattle, didnt know what it was for ages, then someone suggested backing timing off and it went away, with my new setup i.e intake carbs etc. i could hear that rattle much better for some reason and knew straight away

 

[Dennis H]

My 440 must be unique, stops pulling at about 4850. Don't think it's ever been to 6 Grand.

 

[Meep-Meep]

My 440 must be unique, stops pulling at about 4850. Don't think it's ever been to 6 Grand.

You probably left that egg between the gas pedal and the floor.

 

[747mopar]

My 440 must be unique, stops pulling at about 4850. Don't think it's ever been to 6 Grand.

Must be because this motor loves to be revved!

- - - Updated - - -

back your timing up a couple of deg

I think I just need to hire you Charlie, you've helped out a ton on getting this car back together and now your successfully diagnosing my problems. Alright now somebody explain how timing can make a rattle noise only after shifting gears "WEIRD"? Looks like it's back to the adv curve tinkering again. Thanks guys

 

[benno440]

detonation man, high revs and the fuel, mine did the same thing, im sure a guru will tell us why

 

[383man]

It pings after shifting because you just lugged the motor some as after you shift the eng lugs because of the gear change and the overall gear ratio changing it will cause the rpm to drop some and if your eng is right on the verge of pinging that rpm drop and slight more lugging on the eng when the pedal is still mashed is enough to cause the ping. Ron

 

[747mopar]

O.K I guess I was still in denial that it was pinging because it sure didn't sound like it and it only sounded like the pass side but hey I'm just an idiot and now I know. Had already planned a dyno session next Spring and it just keeps sounding better and better (maybe I'll learn something). Thanks

 

[SureGrip]

Glad you found a solution....my first guess was valve float.

 

[bigmanjbmopar]

You probably left that egg between the gas pedal and the floor.

lmao Dennis left a whole McMuffin down there lol A true road warrior!