Ok, i just bought this trans am with a little bit of problems. I was wondring if you guys could help with the trouble shooting.

It has this very odd noise when running. It is a thud thud thud thud that goes in sinc with the exaust burble. I have looked and listened and poked and proded and believe the sound is coming from the front of the engine, possibly the harmonic balancer? I watched it spin as the engine was idling and every revolution of it resulting in a thump. the engine runs and drives. but i am truly cluesless. can you give me some ideas of what to check out and look for?

there is also another thud that happenswhen driving. it comes from the rear passenger side tire. it happens every once and a while. its not just when accelerating or deceleration it happens just out of the blue. I was thinking that the drum could be warped possibly,, what do you guys think?

this car has sat for about he last six months so i dunno if the engine is just having some waking up problems or not, oh yeh, its 305 non h.o. verified by my vin. if this helps anything. any suggestions/comments would be very helpful. i thank you and wanna say hi because im new to this board.

thnks ahead of time

chad

 

Welcome to the boards.Are you sure the thud is coming from OUTSIDE the engine, and not INSIDE? It could be any number of things.... but if it's internal, almost sounds like rebuild time .

As for your other noise, if you hear a clunk, I'm willing to bet you've got a shock loose or bad, so definitely get underneath and check them out! Don't forget to search here, you can usually dig up the info for what you need. Hope that helps you some.


By the way, where do you live? I test drove an 85 T/A that did everything you described a couple weeks ago.

 

I live in indiana. i bought the car in southern indiana.

 

how do you test for a bad shock? im 16 and the most ive done to a car is change alternators starters and give tuneups. i know nothing about suspensions but im mechanically inclinced. i just need to know what to check for

 

If it's making a clunk, the shock is probably worked its way loose, so for starters, look at the shock on that wheel and see if it's connected tightly. Look for broken bolts, etc. Grab it and try to move it around, it it has any play in it, it's loose. If it checks out OK, (this is the way I've always checked them) then try "bouncing" the car over the back 2 wheels and see how it responds. If it comes up tight with minimal bounce, your shocks are probably good, if it bounces extendedly (up, down, up down) it's probably time for a change. Also check for leaks in the shock, if it's leaking the shock will look wet or look really dirty where road grime, etc. has stuck to it, and that signifies time for a change.





Why didn't I think of this one earlier... Is your exhaust tightly in place too? If it's loose, you can get a clunk out of the blue, but you'd also probably have a rattle with it.

 

well ill check those things wendsay (im off) i was wondering where to check on the exaust. i thought this was what it was at first but it seemed to clost to the engine. would an exaust manifold leak make that kinda noise?

whats the chance i have a knocking rod or snapped crank and it still running ok besides the thump?

ive got a theory its the harmonic balancer. because of the wobbling. if my idea is right will this cause some long term problems or having driven it like this hurt the internals?

thanks for the feedback man

chad

 

If you have a knocking rod, that engine will stop very very soon, and can very possibly damage that block beyond repair. If your crank is snapped, it would have stopped already. The harmonic balancer is wobbling? Get it replaced, that kind of vibration can cause some damage if it's not remedied soon. An exhaust manifold leak will sound more like a "tick" than anything, and probably not very loud. put your hand near the manifold when it's idling, can you feel exhaust excaping anywhere? (try to keep your hands away from the accessories though, don't want any injuries ) Hope that helps you out.

 

how exactly do i go about replacing a harmonic balancer? i figure im gonna have to remove the radiator the fan shroud, the belts, but how do i remove the front crank pulley?
how do i remove/install a new harmonic balancer?

thanks for your help man. your saving my life

 

if you are going to change the balancer, may as well put a timing chain on as well, I'll PM you with the details.

 

I had a harmonic balancer once that the outer ring separted from the inner part that mounts to the crank. That may have happened. you won't need to remove the Radiator or fans to switch in a new one though.

I agree with the timing belt as well. Only like $15 and well worth it on an engine with miles on it. PM me with your location. I'm near southern IN as well in Louisville, KY

Hodge

 

For the rear, first check to be sure that the spare tire and jack are secure. You might also check to see if the previous owner put stablizers on the springs, sometimes those can slide around the spring and hit the frame.