Ticking Lifter?

[fireball517]

Is this a lifter or something worse clicking?

350 SBC: http://youtu.be/hNjsSZ-Fq-0

 

[PrairieDrifter]

I cant really tell from the video but it doesn't sound like its a fast enough tick to be a lifter I cant tell with all the other sounds though.

 

[chengny]

X2 The reaper on the frequency of the tap - seems too slow for a valve train noise.

Valve train noises occur at half of crankshaft speed. So unless you're highly experienced (and I'm not), you can't tell by listening whether the noise is happening at 700 rpm or only 350 rpm. And that's under the best conditions, with no exhaust leaks and standing right on the engine. Trying to diagnose using that video....well, let's just say it wasn't possible to make a precise assessment.

Let's just say for the sake of argument that you were idling at 600 rpm. 600/60 seconds = 10 rps (revolutions per second). Valve train noise is half crank rotational speed so, 10/2 = 5.

Trying making a noise with a frequency of 5 raps per second. See what he means? Your noise is more like 2 per second - too slow for any valve train component.

If you want to verify, use a timing light like this:

Hook the timing light to any one cylinder and watch the flash illuminate the timing mark. Stare at it for a while and see if the flash is in synch with the knock. If it is, then it is likely to be valve train related (rocker arms, pushrods, lifters, camshaft, cam bearings, timing chain and gears).

Not related to your sound - just as general info.

If the noise seems twice as fast it is probably in the crank, mains, rods, rod bearings, wristpins and pistons.


I can't think of any internal engine component that cycles at such a low frequency. I would take a close look at external stuff, specifically belts and belt driven accessories.

 

[fireball517]

Ok, thanks. Here is a better audio recording. YouTube narfed the video. https://clyp.it/e4dk5ngm

 

[chengny]

Okay - now that sounds about like 1/2 crank speed. And it doesn't sound like a catastrophic failure is about happen (rod bearing). It is the mostly annoying sound that comes from a gap in a single valve's drive train.

You need to pull a valve cover (make your best guess at which side) and go down the line of rocker arms. Take each arm - one at a time - and push down on the push rod side. Do it until you find one that is loose.

If you find a push rod that can easily be depressed, pull the associated lifter.

Once you locate the lifter that is causing the noise, you will need to determine the reason for its malfunction. Rather than me typing out my own possible causes, I suggest you read the following from Hemmings. Their writers are much smarter than I.


There are four types of noise that can be caused by an inoperative or failing valve lifter:

1) Loud, rapping sound: This can be caused by the plunger being stuck in the body, usually due to excessive varnish between the plunger and body, or by dirt or other foreign materials wedged between the plunger and body. Another cause of a loud rapping sound is an excessively worn base or foot on the lifter itself.

2) Moderate clicking noise: This can be the result of varnish or a worn lifter bottom. The noise level depends on the amount of varnish and the degree of wear. Two other causes of a moderate clicking noise are excessively fast or slow leakdown. Slow leakdown generally will cause the engine to be noisy only when cold and the oil is thick. With fast leakdown, the valvetrain will be noisy when the engine is warm. Fast leakdown will also occur if the ball-check in the lifter fails to seal.

3) Intermittent clicking: This type of noise is hard to locate by its very nature: There will be a few clicks, and then it will be quiet, but the noise will reappear after a short period of time. The usual cause of intermittent clicking is a very minute piece of dirt that holds the ball check off the seat for a few seconds and then passes through. In rare cases, the cause of the sound is a pitted or flat spotted ball-check.

4) General valvetrain noise: When the sound is throughout the entire valvetrain, the cause is usually the weight of the oil or the oil supply itself. Too much oil in the crankcase will cause foaming and aeration. When air gets into the lifters, they will fail to operate properly.


I am sure you know this but just in case:

IF - FOR WHAT EVER REASON - YOU SHOULD REMOVE MORE THAN ONE LIFTER, BE SURE IT GOES BACK IN THE SAME LIFTER BORE IT CAME OUT OF. DO NOT SWITCH LIFTERS FROM ONE CAM LOBE TO ANOTHER. IF LIFTERS GET SWITCHED FROM ONE BORE TO ANOTHER, THE CAM LOBES WILL BE WIPED - AND THAT WILL HAPPEN SOONER THAN LATER. IF SOMEHOW, YOU GET ANY LIFTERS MIXED UP AND CAN'T REMEMBER FOR SURE WHERE THEY CAME FROM - BITE THE BULLET AND BUY A NEW SET (OR AT LEAST ENOUGH TO REPLACE THE ONES THAT YOU ARE NOT SURE OF).

YOU CAN PUT NEW LIFTERS ON AN OLD CAM BUT NOT THE OTHER WAY AROUND. AND YOU DEFINITELY CANNOT SWITCH EXISTING LIFTERS FROM CAM LOBE TO CAM LOBE. CAM LOBES AND LIFTER FACES ARE LIKE SWANS - THEY MATE FOR LIFE!

 

[Stepperado]

I did not listen to the sound byte, but.............

at any given time when the engine is stopped, a valve can be partially open and all the associated valve train to that lifter will have no clearance in it. So if the clicking noise is caused by a loose valve train (the adjusting nut on top of the rocker arm has backed off of its adjustment) it may not be detected.