I have a knocking sound that sounds like its somewhere near the powersteering pump. It is a knocking sound that doesn't have any rhythm to it (sperratic sound). If it is rod knock would it have a continuous, rhythmic knocking sound? Anyway to determine if it is a rod? Tricks? Tips? What causes rod knock? whats it hitting?

I plan removing the waterpump/power steering belt to see if it goes away.

I suspect a fuel pump. A bud of mine almost went nuts over a knock in the engine (finances were low and he couldn't afford an engine rebuild). I listened to it and said WTF, let's try a fuel pump. Problem solved. I hope that you can be so lucky!

Nope, its electric. Can the rods be changed by lifting the car up and taking the oil pan off? Or do i gotta pull the motor?

Once the oil is heated up at least the rod knock should be more or less continuous. Had a similar situation with my car - turned out to be a bolt that I dropped and it fell in between the header tubes. Would clank sporatically and sounded like the engine was falling apart. Magnet stick fixed the problem after a couple hours of head scratching and 5 min of actual work!

If it's knocking, a bearing probably ain't going to fix it. The crank gets ground out of round by the spinning bearing. You probably aren't going to be able to get the pan far enough off to tell anything without raising the engine a few inches. Good luck, hope you find an easy fix.

wont a rod knock change or go away if you pull the plug wier on that cyclinder and run it? Id try that and check the harmonic balancer/flywheel bolts

the rod would still move, right? The piston still moves there just isn't any spark. CLick on the link

http://img.photobucket.com/albums/v243/shawntmartin/4-Stroke-Engine.gif


I have a very loud exhaust. Should the rod make noise if i unplug the dist. wire and just try to crank the engine?

the link is not working

Its just link of a moving combustion engine that shows the rod still moves even when isn't a spark plug wire attached. (in reference to MWilsons post)

yea but if you take the plug wire off its not under load anymore right? so it might quiet down some or go away altogether. when ever I heard rod knock it was usually consistant with the engines rpm's anyway.

on a 2nd gen it is 10x easier to pull the engine than trying to pull pistons out the bottom of the car.

I am an amateur and I can pull my motor in about 2 hours total from start to finish.

That being said, a tool that I use ALL THE TIME is a stethoscope. You can locate odd noises all of the time with it.

yea but if you take the plug wire off its not under load anymore right? so it might quiet down some or go away altogether. when ever I heard rod knock it was usually consistant with the engines rpm's anyway.

I see, I'll give it a try! Thanks guys

Correct me if I'm WRONG here, but I DON'T think pistons will come outta the bottom of SB's!! Crank, yes!! Pistons, NO!!

And fwiw, onna the three Brothers that ran the DX gas station back when I was a kid in highschool bought a crank journal grinder that actually ground the crank in the block by spinning the crank at the ring gear using a high torque, slow rpm electric motor as it ground away..

In fact, I crawled under the car and watched it work... Sucker bobbed up and down, round and round as the crank spun and it ground away!!

And it was the Baby-Brother that helped me stuff the 232" Stude V-8 and stick OD into my first '52 Willis Areo Eagle H/T car back then.

pdq67

At the end of this year I was interested in pulling the engine out and having the block bored out .030. If this is a rod problem, I wonder if I can limp through the car show season until pulling it in Oct.

I doubt it b/c they do nothing BUT get worse!!

pdq67

The only GM engine I ever messed with that had room to pull the pistons out the bottom end is a 366 truck engine. I tore a rusty one down and was tapping on the top of one to loosen it up and it fell all the way thru. Sure made that disassembly easier!

wont a rod knock change or go away if you pull the plug wier on that cyclinder and run it? Id try that and check the harmonic balancer/flywheel bolts
if ti is a rod or a wrist pin when you remove the plug wire to that cylinder the noise will change dramaticaly.That will at least rule out a cylider problem.dont forget it could be a cracked or broken piston skirt...dont forget to check for cracked flywheel.that can sound like a rod sometimes aswell

If it is a a rod, it is only going to get worse. The more you run it the more flack it's going to put through the engine. The crank might be salavagable now but later it won't be. Also, the block can become so contaminated that it too won't be worth taking the chance of FOD'ing (foreign object damage) the new engine parts out.

So, cut to the chase and pull the engine.

Rule out the easy stuff before you assume it's a bad rod bearing. Water pump bearing can cause a dull noise. Header tube hitting a frame. Bad fuel pump and or pump pushrod, bad motor mount. Bad oil pump. Bad PS pump bearing. You might hear the noise up front, but in a motor, the cause can be someplace else and this is just where it's audible. Pulling the plug wire will help. Once compression and combustion load is eliminated, the bearing won't make as much noise. Also, try some heavier oil. If the noise goes away, suspect a bad bearing bacause the heavy oil will float the bearing for a while and crutch the oil pressure. When the oil heats up, and pressure drops, the noise will come back if the bearing is bad. How's oil pressure? Anything over 15 hot idle is fine. All the things I mentioned can cause a heavy noise in a running engine. I bought a VERY nice Corvette worth 20k for $7700 because the freshly rebuilt LT-1 had a rod knock. Threw belts a lot, too. The owner poured a pile of cash into the car...only to have his 2k mile engine go bad. So he was told. He got so frustrated he just wanted it gone. I bought it. Brought it home. I tightened the harmonic balancer down properly. Noise gone. Total tine invested was about 3 hrs. So investigate the small things first.

you try pulling plug wires yet?

Nope, i'll be doing that today. Post results in a few hours...

A guy I went to Jr. College w/ back in the late '60's bought a used, darn near BRAND NEW, '64 Boat-tail Buick Riv.

He was SOOO prouda that car!! BEAUTIFUL CAR!!!!!!

Anyway, it got ta making a bunch of noises so he took it into the local GM Dealer in town and they told him the engine was SHOT!!

He paniced and traded it in on a Chevy or whatever, only to find out later that all that was wrong w/ it was that it had a stuck lifter!!

He was SICK!!

Check way into this before you panic..

pdq67

I pulled the wire for 1st cylinder and the ticking stopped completely.:mad::whine: It didn't just get harder to hear, it vanished. I was really hoping for a powersteering problem. But, it is more of a loud ticking than a knocking I guess and it sounds like it is right next to the exhaust of the first cylinder. It may be a header leak. I know your all gonna think I'm an ass, but I shaved a tiny bit of the corner of the header (where it bolts to the heads) because thats the part that gets hung up when trying to install the drivers side headers form the bottom up. Super tight fit. And, I planned on a new set in the future. I hope thats the problem. Problem though, theres no way to test it without buying new headers. Crap.
By the way, the ticking never goes away. Cold engine, warm engine, doesn't matter. Any damn tricks to find if its a header leak? Is that something I could feel with my hand? See in the dark? I don't know...

UPDATE. I'm pretty damn excited. I just pressed a small wash cloth up tight wear the header was shaved and me and my wife both say the noise decreased a lot! Actually she said it was gone. I think its a header leak.... and now I need headers.

Whaaahoo!!

you r a lucky guy.We r all here to help and there is no such thing as being an ass,just un educated.now you r educated on what a header leak can sound like!if you have someone plug the end of the exhaust pipe on that side then it should get louder.good luck!

Loosen it up and install Mr. Gaskets white jobbers and then keep retightening them over and over hot/cold, hot/cold, hot/cold until ALL the little bolts cinch down!!! It took me about 6 or 7 times over a week to finally get mine to seal.

It's a pain, BUT it WILL work!!

OR you can use the crinkly stock metal faced jobbers too! If you have a set of them in a complete overhaul gasket set??

GLAD you found it!!

pdq67

I actually think I shaved a little too much off of the corner and I don't know it will ever seal 100%. I probably need a new set. Knowing that it is a leak, I can actually live with it because its only noticable if the engine is running, the hood is up, and you lean in with your head.

good deal

See here is when you use man logic. Tell your wife "sense we thought it was a rod and we would've had to tear the motor down, I actually saved use $400, so can I buy the ceramics now"

;)....