I have a 99 neon and all of a sudden I was hearing a knocking noise from the top left side of the engine sounds like its right under the valve cover. Anybody have any ideas?

I have a 99 neon and all of a sudden I was hearing a knocking noise from the top left side of the engine sounds like its right under the valve cover. Anybody have any ideas?Are you sure its a rod knock? If it is a rod knock just drop the oil pan and unbolt the rods, check the crank for damage and wear, if all is good slap in new bearings and rod bolts and put it back together.

It could also be valve lifter noise. Is it a ticking noise and gets faster when you accelerate?

Are you sure its a rod knock? If it is a rod knock just drop the oil pan and unbolt the rods, check the crank for damage and wear, if all is good slap in new bearings and rod bolts and put it back together.

It could also be valve lifter noise. Is it a ticking noise and gets faster when you accelerate?
It kinda sounds like a ticking noise but it sounds kinda louder than a lifter, A friend thinks it may be a valve spring. it gets louder with speed though.

It kinda sounds like a ticking noise but it sounds kinda louder than a lifter, A friend thinks it may be a valve spring. it gets louder with speed though.

Its a Dead lifter. If the engine starts running on 3 cylinders above 3000RPM then it is a Broken Valve spring.

If the Lifter died that means the oil passage/ orifice is clogged. This happens when Carbon and dirt clog the hole. Can be caused by not changing the oil regularly.

Go buy a can of engine flush and one quart of ATF "Dextron3". Pour half a quart of ATF into the engine and Drive the car down the highway at an Elevated RPM(out of overdrive or 5th gear) around 3500 RPM for 5-10min. Be Easy on the engine, you want RPM, not load. Once you get home empty the can/Bottle of engine flush into the engine. Let the engine Idle for 5 min. DO NOT DRIVE IT OR REV THEN ENGINE AT ALL!!! After 5min change the oil. Remember to leave the filter and drain plug out. Dump one quart of Oil down the filler to Flush the crape out. Then complete your oil change.

Then Drive the car for a a day or two. If the problem isn't corrected by then, you have a mechanical failure and it will need to be replaced.

In most cases it should sound better after the oil change.

Good Luck

It kinda sounds like a ticking noise but it sounds kinda louder than a lifter, A friend thinks it may be a valve spring. it gets louder with speed though.

BTW: Broken Valve springs dont knock or make that much noise.

Its a Dead lifter. If the engine starts running on 3 cylinders above 3000RPM then it is a Broken Valve spring.

If the Lifter died that means the oil passage/ orifice is clogged. This happens when Carbon and dirt clog the hole. Can be caused by not changing the oil regularly.

Go buy a can of engine flush and one quart of ATF "Dextron3". Pour half a quart of ATF into the engine and Drive the car down the highway at an Elevated RPM(out of overdrive or 5th gear) around 3500 RPM for 5-10min. Be Easy on the engine, you want RPM, not load. Once you get home empty the can/Bottle of engine flush into the engine. Let the engine Idle for 5 min. DO NOT DRIVE IT OR REV THEN ENGINE AT ALL!!! After 5min change the oil. Remember to leave the filter and drain plug out. Dump one quart of Oil down the filler to Flush the crape out. Then complete your oil change.

Then Drive the car for a a day or two. If the problem isn't corrected by then, you have a mechanical failure and it will need to be replaced.

In most cases it should sound better after the oil change.

Good Luck
it dont get louder with speed but faster and you cant hear it, Ill try that I just bought some mobil one oil yesterday to change the oil might as well try that. thanks ill let you know what happens

I have the same prblem it gets faster as revving up and then goes a little faster when clutch is in and then calms backdown. Took valve cover off and rockers look good so do springs. But the knocking goes with the rocker arms on the 3 cylinder.

I have the same prblem it gets faster as revving up and then goes a little faster when clutch is in and then calms backdown. Took valve cover off and rockers look good so do springs. But the knocking goes with the rocker arms on the 3 cylinder.


You wont be visually locate a bad/clogged lifter. If you need to track it down youll need a stethoscope and move it along the valve cover till you locate the little bugger. Then Replace it is the above fails. My recommendation is to replace all of them at once. They are a dealer only part. Autopart stores dont stock them.

Well believe it or not..... I started loosening the bolts to the valve cover and someone came by and wanted me to start the car first. I turned out to be a loose spark plug it sounds fine now. Just changed the oil too.

You wont be visually locate a bad/clogged lifter. If you need to track it down youll need a stethoscope and move it along the valve cover till you locate the little bugger. Then Replace it is the above fails. My recommendation is to replace all of them at once. They are a dealer only part. Autopart stores dont stock them.

So it was a puffing/popping sound huh??? lol

Well believe it or not..... I started loosening the bolts to the valve cover and someone came by and wanted me to start the car first. I turned out to be a loose spark plug it sounds fine now. Just changed the oil too.Loose spark plug, huh...I will have to keep that in mind if I hear of something like this again.

I had one of those....too.
I had a loss of power too. I thought I cracked my exhaust manifold.

I sort of unconsciously check my plug now because of it.

I never commented because the "knocking sound" description conjured images of serious mechanical nightmares that I could not finger affirmatively.

Good going. Just a spark plug.