What does a hydraulic lifter sound like when it goes bad?

I've had this strange rattling sound in the front of my engine for a couple weeks. Now that its cold here, I've definately determined that it is affected by oil temperature...as the noise is completely absent when the oil is cold and thick...but as I reach the end of my 16 mile (one way) commute to or from work, I can hear the rattle.

I thought I had isolated it to the oil filter...which had been replaced with an oil change a few weeks ago...but I just replaced the oil filter again the other day and the noise is still there...although it does seem diminished in volume...since I really have to listen for it now instead of the noise driving me nuts. Even though I put new lifters in with my gear drive cams last winter, I'm wondering if I don't have one going south on me.

So can anyone help me rule that out or in?

I would like to hear what the symptoms of a bad lifter are also. Anybody know?

The thing to keep in mind about lifters is,,,that when you put in adjustable lifters if they go out of adjustment it will throw your timing off to the point where the motor will miss badly. Lets say the front jug has a lifter out of adjustment, you will still have a spark at the plug but it will be out of time. Also be aware that Harley makes the same size oil filter for your particular bike but,, they come in different size microns of filtration. If for instance your using the wrong size micron filter it will slow the flow of the oil going thru the filter, thru the lifter and into the top of the jug, until the oil warms up and thins out. First Is your motor missing, or sounds like the spark plugs are fouled out? Next, check to see what size micron filter you are using. If those two check out the rattle may be radiating from the primary chain. Check the tension of the primary chain. One of those above may be the problem. And lastly keep in mind that adjustable push rods will sound louder than stock rods. Ride Safe, David.

A couple of things there I thing you are mistaken about. The lifters and pushrods have nothing to do with timing...they merely control the open and closing of the valves in the head. So if they are out of adjustment, the valves may open too far, or not far enough, but they will be in time with the firing sequence since the camshafts are driven directly off the crank shaft. I have gear drive cams, so there is even more positive engagement with the crankshaft than with the chains.

Yes the moco had two types of oil filters for twin cams...a 10 micron and the new 5 micron filter. The thing is, according to my dealer, the 5 micron supercedes the 10 micron and as dealers used up their stock of 10 micron filters, they can't replace them....making only the 5 micron available unless you go aftermarket on filters.

I have checked primary chain and compensator sprocket nut and both are good and tight. I use a hayden M-6 automatic primary chain adjuster too.

I have had a chance to use a stethoscope all over the motor since my post, and the only place I can hear anything but a sweet hum of moving parts, is in the rocker boxes. Soon I'll be putting it up for the winter; and then I'll pull the rocker box cover and see if something is loose...and while I'm at it, I'll readjust my pushrods. I'm probably also due for a change of spark plugs; so I'll take care of that.

So heres my next question:

To help your lifters fight bleed down, in order to keep the valve train as quiet as possible, do you use more preload on the lifters or less? I currently have mine set at .100" preload.

Well I do not think I have an answer to the question of symptoms of a lifter going south. I did find this link. http://www.bai-no1.co.nz/techtips.htm Not being real up on a lot of this stuff as to the tech side.

My bike has a lot of lifter noise, tapety tap tap from idle hot or cold no diff..up to about 40 MPH Going Hiway 50-80 Mph the bike is solid, engine sound is good, plugs are good. Maybe I have no issues at all.

I have a EV3 cam with adjustable rods, SE Hi flo kit, Mikuni 42 and a D & D Fatcat. Only 7500 Mi. on motor. It seems the Tap has become more pronounced, it has always been noisy but seems to be more so now. Hot or cold no Diff. I listened to couple of buddy's stock bikes and there was no noise at all, good n tight one has 70k on bike.

Evo BT BTW

Try the baisley oil pump spring...made by baisley performance (head porters, engine builders). Cost is $12.95 + S/H. It really made a huge difference in the noise I experienced with my motor build. It raises the oil pump pressure slightly to keep the lifters pumped up...which quiets down the valve train noise.

For more info and opinions on this read here:
http://www.v-twinforum.com/forums/showthread.php?t=56650&highlight=baisley spring

I don't know what caused this recent disturbing noise, that I can't find the source of...but prior to that, it hummed like a super powered sewing machine. Before the baisley spring, it had that clackety/tapping noise.

My current noise doesn't seem to increase and decrease in frequency with the rpm...so I don't think it is the valve train...but I did take a chance on a new performance part company that promises high quality at half the price...so I fear it may be the lifters I bought from them, even though I can't hear anything wrong down there with the stethoscope.

Your absolutly right Seahag, I should have been more clear on the "timing" subject. The lifters and tappets only control the opening and closing of the valves. If the pushrods slip out of the pocket of the upper valve it will seem as though it is out of time. Thanks for the correction. Ride Safe, David.

It may weaken some, but if you saw the difference between it and the wimpy stock spring, you'd know it could never be worse than stock.

A collapsed lifter is a very loud tapping sound. If it is one that is not holding pressure very well, it makes a tick-tap sound depending on how hot the engine is and how bad it is. Usually a bad hydraulic unit fails when hot because of a poor seal or it may have debris etc. If oil pressure drops when hot, it may collapse due to low oil pressure. Check your hot and cold oil pressure.

Get a long wooden dowel and place it on each push rod tube. The one that is making the most sound gets you a lot closer.

Some notes:

Low oil pressure can cause this problem so, if oil pressure is suspect, check it.
A failed roller axle can make a similar noise right up 'till it breaks and destroys a whole bunch 'o stuff.
A push rod tube that is rubbing on a push rod makes a ticking sound also and can be seen pretty easily by looking at the tubes will idling.
A bad rocker bushing, collapsed valve spring etc are pretty much not gonna sound that way.