Hey, first post here, but ive been reading these forums for awhile now. Little history. Ive got a 86 monte carlo LS with a 71 307 in it. (I bought the car this way, intend to swap to a 350, cant afford it at this very moment)
Has a turbo 350, and a recently installed ford 9" with a detroit locker and 3.89 gears from Quick Performance. Onto the issue.
Ive been driving the car since july, has had a constant lifter tick but that hasent gotten any worse(i was about to get into that next until i heard this noise..) I installed the ford 9" recently and in doing so the car began running different rpms. The original rear end had ~2.42s in it now cruising around town at about 35 im running 2500 rpms instead of 1500. Well there seems to be a knocking noise in the engine now, it may have been there before but i never saw it. The noise only happens at 2500-4000 rpms, and only while maintaining speed/rpms in the engine. After 4000 rpms it only appears when accelerating. I can also make it happen in park by revving the engine and holding it at those rpms. Im afraid its a lower end knock in which case its time for the engine to go. But it doesnt sound nearly as loud as a typical rod knock. Heres a link to video. Not my video, but it sounds exactly the same.
Ive tried retarding timing, ive tested for connecting rod noise the only way i know how to, pulling plug wires 1 at a time to see if it lessens or goes away. Neither made any difference. It sounds to be on the driver side, and i can actually hear it better in the driver seat then i can next to the engine(i assume it is just echoing through firewall and engine/fan noise is covering it a bit otherwise.) oil change was done not 500 miles ago just before the rear end swap. Also, i went with synthetic oil.... i did some research online and didnt see anything wrong with that for these old engines.. but maybe i missed something? During the last oil change i saw no metal shavings in oil or anything either.
Has a turbo 350, and a recently installed ford 9" with a detroit locker and 3.89 gears from Quick Performance. Onto the issue.
Ive been driving the car since july, has had a constant lifter tick but that hasent gotten any worse(i was about to get into that next until i heard this noise..) I installed the ford 9" recently and in doing so the car began running different rpms. The original rear end had ~2.42s in it now cruising around town at about 35 im running 2500 rpms instead of 1500. Well there seems to be a knocking noise in the engine now, it may have been there before but i never saw it. The noise only happens at 2500-4000 rpms, and only while maintaining speed/rpms in the engine. After 4000 rpms it only appears when accelerating. I can also make it happen in park by revving the engine and holding it at those rpms. Im afraid its a lower end knock in which case its time for the engine to go. But it doesnt sound nearly as loud as a typical rod knock. Heres a link to video. Not my video, but it sounds exactly the same.
Ive tried retarding timing, ive tested for connecting rod noise the only way i know how to, pulling plug wires 1 at a time to see if it lessens or goes away. Neither made any difference. It sounds to be on the driver side, and i can actually hear it better in the driver seat then i can next to the engine(i assume it is just echoing through firewall and engine/fan noise is covering it a bit otherwise.) oil change was done not 500 miles ago just before the rear end swap. Also, i went with synthetic oil.... i did some research online and didnt see anything wrong with that for these old engines.. but maybe i missed something? During the last oil change i saw no metal shavings in oil or anything either.
