I have a 2.4 with an intake and exhaust kit and think i may have blown a rod, i hear a knocking noise when the engine is in the 700-2000 rpm range. i also hear a sound that makes my car sound like an airplane when driving and dont know if its a grinding or because i removed the stock air box.

Hey man, I was reading one of the other forums, can't remember which one, but they stated that it could be from the timing chain slapping/ rubbing the timing chain cover. I hope this has helped a little. My car is starting to sound like what you describe, only mine is a 2.2l. I am gonna try this before I get too hot and heavy with expensive work.

Here you go man, this the statement I was refering to:



"Actually, I'm going to go out on a limb and bet it has the 2.2 OHV motor. The timing chain tensioner is notorious for wearing out and the chain slaps the cover. The tapping sound it makes is often confused with piston slap.

Anyways, 2000 for a used engine isn't bad if your paying someone to do it. If you want to save some money, you can search for a used engine at www.car-parts.com in your state. Of course you will need all the equipment to change the engine out yourself. If you have a engine hoist, remove the brake master cylinder and pull the engine and transmission all in one assembly. If you have 224K miles on the original transmission, it might not be a bad idea to go ahead and spend $300 on a transmission with ~50,000 miles."

i think if you blow a rod, you would know for sure. i blew a piston rod in my 93 sunbird, after only driving it 10-15 minutes the rod shot through the block and radiator. so if you want to know for sure drive it 10-15 minutes going about 50mph and you will get your answer. i'm doubt there is much of a difference between 2nd gen and 3rd gen piston rods.

First off your dont "blow" a rod, you throw it, and by throwing it means breaking free from the crankshaft and actually going through the block.

Secondly you car wont last much longer if your rod is knocking, by the rod knock is caused by the rod bearing not moving freely with the crank, instead it is actually hitting the crankshaft.




- 2004 Cavalier - 124k, owned since new

I just had this same issue. It was a ticking coming from the top end or so it appears. This is actually the timing chain tensioner which is a hydraulic part that is known to go bad. If you have been driving the car for awhile with the ticking, I recommend purchasing the entire timing kit (chain, tensioner, and guides). Your timing chain if worn will most likely skip a tooth or two and throw off the timing or worse yet could damage the engine if the chain skips on the intake side (the 2.4 is an interference engine).



Drive it like its stolen!