Hey i own a 99' Trans Am 6 speed, everything stock no mods of some sort... first, i been racing my TA since i bought it but one day I fucked up my crankshaft bearings so i decided to get another lS1 engine.... Ok now to the point, i stopped racing after i got my other used LS1 engine but i sometimes give it a punch once in awhile when im driving, all of a sudden i hear a noise coming from my engine like a "TICK TICK TICK" noise but very rapidly when i press the pedal to the metal or when i just press it half way... when it reaches about 4000rpm it makes the noise then it stops and then again but it does it very rapidly....

Ok now i went back to the auto shop that changed my engine n asked them whats goin on! they responded with a scratch on their heads... so they send my car to a pontiac dealer and also they responded with a scratch on their heads... so my mechanic said since i have a warranty on the engine, they were gonna get me another used engine so i said ok.

Ok now i got me another used ls1 engine (2nd engine). I been having it since October 2007.
Everything seems perfect when im driving normal, if i rev my engine it sounds perfect, when im cruising its smooth, when i shift gears is smooth too... now i with this 2nd motor i just put in i never accelerated or raced it... but just today coming from the houston auto show... i pressed the pedal half way when im cruising lets say doin 40mph n the rpm goes from 2500rpm to 4000rpm n UP the stupid noise came back again!!! WTF! the same stupid noise from my last engine was doin it again with my 2nd engine!???

Please if anyone had this kind of problem before and know about it or are/is familiar with it PLEASE tell me! i love my Trans Am i want to get it fixed... Please feel free to ask me any questions, i will tell you what i know! Thank you for your time reading this!

Danny

 

How loud is the noise? Does it sound like piston slap? Can you locate where on the motor it is coming from by lifting the hood and reving the motor? Try to find out exactly where the noise is coming from and let us know. It's hard to diagnose a problem without all of the proper info. Thanks

 

yea we need the type of sound it is... and where it's coming from... any mods? If you can get a video up that always helps as well...

 

Is it an Auto. It could be loose torque converter bolts.

 

I would guess it's not the engine. maybe the exhaust hitting somewhere or something in in transmission... like said above lift the hood and listen to where it's coming from, and try revving it while doing this.

 

Use a stethoscope, best way to locate the origin of a engine noise/problem.

 

We need more information:

Does the tapping noise correspond directly to engine rotation - like one tap per revolution, as in from one cylinder, multiple taps per rotation, or one tap for every two rotations, etc?

Is it a tap, or a ticking noise?

When the engine was swapped, what parts were moved fro old to new?

What kind of exhaust?

What kind of ignition wires?

Does it make the noise with clutch depressed also?

etc.

 

maybe a loose plug or exhaust manifold leak???????

 

Loud valve train, Piston slap, Exhaust leak, bent pushrod, maybe the needle bearings came out of the rocker arms, failed lifter, spun bearing.

The last 2 are the ones you hope you dont have.

 

its pretty loud, i could hear it from inside the cockpit... it sounds like some lightweight metal tappin on something but it does it very rapidly (sorry if it dont make sense) i really cant locate it cus it only happens when im on the road n i accelerate either metal to the petal or halfway... if its just in one spot n reving the motor it sounds smooth like it should... i kno pretty weird... yea i kno its hard diagnosing online haha but thanks for asking...

 

yea im thinkin about that too... cus i mean im on my 2nd engine n its doin the samething from my 1st engine i put... so its weird that its doin it again same problem...

 

ima try to get a video of it but it will be hard cus of noise insulation u kno n the noise only happens when im on the road n i accelerate... n no i dont have any mods everything is stock from the factory

 

sounds like detonation, get someone to hook it up to a scanner

 

no... its a 6 speed manual tranny

 

Yes it corresponds with the engine rotation... its multiple tap/tick per rotation
Its more of a tickin noise, or like a piece of lightweight metal hitting on something.
when i swapped it i got a new :
waterpump
oilpan gasket
front seal
oil drain plug
ac tensioner
tensioner drive belt
thermostat
2X exhaust gaskets

i still have the original exhaust from the factory
same goes with the ignition wires, coils...everything is stock
no it doesnt make that noise when clutch is depressed

 

thats exactly what i was thinking. as mentioned above, do you know what if any parts were swapped over from the last motor?

 

Well to be honest with you you can have a collapsed lifter. More than likely since it does speed up upon reving of the engine that is the route I would reccommend looking into. The other factor that concerns me is I bet you didnt replace that 98-00 Oil pump which is a piece of crap. Definitely known for low oil pressure problems and more than likely when you got into the higher rpm's the oil pump failed to feed all the lifters and either one overheated and collapsed or maybe it just collapsed considering those lifters sucked too. The LS7 lifters are cheap and an excellent route to help but if you are gonna do that then get a head and cam kit so atleast you'll be happy about gaining almost 100 hspwr or more

 

I am gonna agree with detonation because it only happens under load. Try having a scanner hooked up and drive it around and see if you have any. What grade gas are you using?? I am gonna disagree on a collapsed lifter because if it was collapsed i am sure it would make noise all through out the RPM not to mention it only happens when he drives the car... This is a head scratcher, did the techs at the shops you took the car to road test the car???

 

What kind and grade of fuel are you running?

 

ever since i got it i been puttin 93 premium