What all can cause engine knocking?

Question

I just changed the oil, put in an Oil Treatment (higher mileage engine) and a fuel system cleaner to a full tank of gas. It had a slight chatter before but after I put in the additives, it went away for all of 10 minutes. Now it knocks worse then before and horribly loud while accelerating. If the car is idling, it knocks quiet a few times then theres a knock thats slightly louder than the rest. Any ideas? The cars a 1999 Chrysler Concorde 2.7L DOHC

Answer 1

It depends on the noise. Is it a fast tick tick, noise? Of so it could be a lifter. I had a car that had a noisy lifter for years. Also, if it is lifter noise, it could be caused by the oil treatment or oil if the viscosity (thickness) of the oil is too thick, the oil has a hard time getting into the tiny passages to lubricate the lifters.

If the noise is a slower knock, it is more that likely a rod bearing going bad (time to rebuild the engine).

If you think it is a lifter you may want to try changing the oil again, use a good quality oil, synthetic if you can afford it, no additive, and a lower viscosity like a 5 W 30.

Answer 2

First of all check the oil level, be sure the torque converter is tightly bolted to the ring gear. Check your oil pressure. If it's the same that it's always been, there is a good chance your engine bearings are OK. If it has a tinny clattering sound do the simple things first. Pull the valve cover and visually look at the valve springs. Move the rocker arms by hand both fore and aft of the rocker shafts (there are two of these). Check all 12 rocker arms. If you detect any movement in any direction there could be problems with the roller on the rocker arm, as well as the lifter and or a camshaft lobe could be worn. Don't despair. Everything on top of the motor is easy to get to and is easy to repair. If this isn't it and your certain it's a tinny sound it could be a cracked or broken piston. If it's more like a loud hammering sound you have either a loose wrist pin or a rod bearing on it's way out. Main bearings make a hammer like pounding sound also. You can isolate lower end problems buy removing one spark plug and starting the car. If the noise persists do the same thing to the other three cylinders. If the noise stops while checking any one of the cylinders you've found your problem, at least you've located the cylinder with the problem. You can drop the pan, take the rod cap off and remove the piston and rod after removing the cylinder head. Good luck.

Answer 3

you want to seem up the compression ratio of your engine. even if that's 10:a million or a lot less, you'd be ok using 87 octane gas (accepted). Engine ping or preignition occurs even as the nice and comfortable temperature of compression ignites the gas mix earlier the spark plug has a probability to hearth. it truly is how a diesel engine works. the better the compression ratio, the more suitable warmth is generated on the compression stroke, which skill that's more suitable in all probability to ping with a decrease octane gas. the concern with preignition in a gas engine is that it's going to at last warmth up the piston properly and burn a hollow in it. once you've a truly new vehicle, the pc could modify for the gas that you're using. that's going to modify the gas mix so as that the engine does no longer run too wealthy. A wealthy mix would reason the carbon advance you suggested. If, for some reason, your engine did have carbon advance, this can reason pinging because the carbon would commence gleaming on the compression stroke and ignite the gas earlier the spark plug fires.

Answer 4

A variety of things can cause knocking. Carbon build up in the cylinders or heads, lower octane fuel, timing too advanced. I assume you're talking about combustion knocking and not the noise of maladjusted valves, or a knocking from the rods or wrist pins.

Answer 5

Crack ed piston,connecting rod bearing.bad knock sensor,timing to advanced,low octain fuel,worn out timing chain,and loose rocker arms.

Answer 6

sounds to me like its a rod bearing or if is a double knock then it might be a wrist pin.