Ok, ill start from the beginning...
1. Spun rod bearing
Pull motor, new crank, bearings, oil pump. Install motor
2. ~5000 miles later, strange rattle (not rhythmic)
Pull motor, find loose water pump bolts, tighten, install motor (should have looked it over better, but was anxious) Install motor.
3. Same rattle immediately after install
Cuss alot, throw stuff, pull motor. Yank oil pan off, everything seems fine. Pull timing cover, WHOA timing chain is loose. Wear marks visible on housing.
New timing chain, new water pump, new tensioner, set all the slack in the chain between water pump an crank, popped tensioner out, all slack gone. Seems fine, install motor.
4.Same rattle immediately after install
Cuss more, throw more stuff, seriously debate buying another car....

any help would be appreciated. open to suggestions. PLEASE.
I don't want to get rid of my GT for scrap metal, but I'm almost at that point....

I say get new motor or a used one just one of those days .

did you replace cam and crank timing gears?

no. but i looked them over really good. and they appear to be in really good shape. maybe recently replaced before i bought the car?

This is going to be a dumb question but did u replace your shoes for the chain??? i didnt see where u said u did. and yeah replace those gears, its the only thing left besides the shoes.

yep. replaced guides as well. all the mechanic shops around here say its the oil pressure. but before the noise and even during the noise my OP is sitting at about 20-30lbs

BC Fire 70 wrote:Ok, ill start from the beginning...
1. Spun rod bearing
Pull motor, new crank, bearings, oil pump. Install motor

I dont see where you replaced the rods?


"Oil Leak ? What oil Leak ? Oh, Thats Just The Sweat From All The HorsePower!!"

If he spins a rod bearing no need to replace the rod, i rebuilt my girls 2.4 and replaced the frank and bearings and chain and such and nothing wrong came out of it, and the guy i sold it too still is letting his wife drive it. as a matter of fact, unless its waayyyyy outta round then he will be fine using new bearings and a matched crank, but he will need to measure with a micrometer to tell if its out of shape or not.

Ne who, did you also make sure that between the gears there is NO slack. had that issue on my girls car. Replace those gears, they have kits out there for a reason, and make sure there is no slack between the intake and exhaust cam, and the slack is only where the tenzioner is, any slack anywhere else will cause a rattle after installation. You will need to move the cams slightly to get the chain to tighten up then u can pop the pins back in to hold everything still up top then u will have to move the.crank a hair to tighten everything up on the backside of the motor so the slack is where the tensioner is at. good luck man.

when i replaced the chain, i put all the slack inbetween the water pump and crank gear. in between cams is absolutely tight. along with intake and crank, tight. i spun the motor backwards a tidge put the chain on, and when i release the crank it tightend my slack everywhere. (except the wp n crank) released the tensioner, and pow, no slack. spun the motor over a few times with a breaker bar and everything stayed in sync. no slack, everything was good. put it in the car and cranked it up and my rattle was back... im at a loss. i dont know. anyone wanna buy that motor? got new crank with matched bearings, new chain, new waterpump, new oil pump... shoot me an offer if you want it. i want to drop this nightmare of engineering that GM created. gonna go with a 3.4 swap i think

lol damn if u lived closer i would take it lol. im still telling u throw the gears on and see. dont need to yank the motor for that. either way man goodluck.

u ever figure out this problem? I think I'm having the same issue....


01' Z24 5 speed
422whp/400wtq
T4 Turbocharged
Built LD9
HP Tuners