ws6envy

iTrader: (2)

New motor installed last weekend. First startup was good with no major issues.

But after 1st drive 1/4 mile while its idleing the engine makes a hollow deep metal on metal noise and the entire motor twists to the right (drivers side) for half a second and then does it in closer and closer incriments....


any ideas?

backround....that might help....

motor was balanced for a stock flexplate, but i decided to go manual later on with a stock flywheel.

There seems to be a lot of exhause leaks causing random backfires


any info appreciated

Formula69

i heard your sound file.. with an aftermarket cam you will get a little more engine vibrations than normal.. as for exhaust leaks, seal them!! all that exhaust leaking will throw off the o2 sensors and any other sensors the shitty air gets into and that will throw off the computer... exhaust leaks occur right where the headers bolt into the heads and at the collectors.. also check the welds on your headers, one of mine was bad and caused a leak.... if you went manual then you got rid of the flex plate altogether and put some sort of flywheel (stock or aftermarket) in to mate with the clutch so thats not a big deal... lt1s from the factory are balanced the same for their stock flex plates and for stock flywheels (having two different balances for each would be costly for poor old gm) the reason the engine is twisting to the right is because thats the way the motor torques.. it has to do with the way the pistons move and the way the cylinders fire and then you get into the whole torque equation and i dont want to explain it but its normal as long as its not REALLY bad... my advice to you would be to get some sort of tune going... are you on stock injectors or higher lb/hr injectors? have you checked your spark plugs since you started the new motor? have you re-torqued the header bolts or anything since its been together? does the car run clean and feel somewhat normal? if not are you sure the spark plugs are plugged into the opti correctly? check all that crap andj then we ca narrow your problems down but just remember, every time you finish a car like this you will run into ALL sorts of problems unless you are Carroll Shelby or Chuck Noris

ws6envy

iTrader: (2)

its on a fresh tune from madz28, the injectors are fms 30#. ive had a cammed stock motor before but it didnt look/sound like this....its a rythemd' clunk and a violent shake....i am going to go over it today.


thanks for your input

93BlackZ

i know this has nothing to do with the internal part of the engine but did you think about the mounts?

ws6envy

iTrader: (2)

update...traced the knock down to cyl. 5, if i pull the injector harness the motor stops clunking...

also the o2's read .300 / .800

93turboLT1

Sounds like your flywheel isnt' correct for your motor...unless it was balanced back to stock LT1 specs. Had the same deal with my first motor, when i put the stock flywheel on...the bitch shook the whole car. I thought it was the motor itself but realized my mistake when i pulled it and balanced it with the stock flywheel. they had to drill the origanal wieght off, then balance it.

DeltaT

iTrader: (5)

I damn sure wouldn't drive it another foot until you figure it out.

Jim

ultra 94 z

iTrader: (2)

Sounds like an internal engine noise if u pull the injector wires /kill that cylinder and the noise goes away you have found your problem cylinder think about pulling it appart and re checking evreything.