AJ_92RS

I have a tick in my engine that is primarily heard at lower RPM. It's rather loud, and IMO, a deep pitch.

It's barely audible above 2500 RPM, and totally gone at 3000 RPM.

I'm concerned that it's piston slap just because of how loud it is.

So this is what I did.

I had a friend time me for 30 seconds while I counted the ticks. I did them in multiples of 10, putting dash marks on a piece of paper, for every 10.

When 30 seconds had passed, I counted 13 dashes of 10 (give or take a few ticks) I.E. 130 ticks per 30 seconds, or 260 ticks per minute.

The engine was idling around 500-600 RPM (it fluctuates a bit, so it's hard to say and exactly what RPM.)

By doing that I suspect it's a valve train tick. Only because multiplying 260 x 2 equals half the crank RPM of 520.

Would that be a correct assumption? Or could it still be piston slap that only occurs on the compression/power stroke since those are the two consecutive strokes when the cylinder has pressure, i.e. piston rock at TDC.

I wish I could be more descriptive of what the tick sounds like, but honestly I've never heard piston slap or rod knock. A few people I've had listen to it said it certainly isn't rod knock because rod knock doesn't go away at higher RPM.

I have new lifters and a new cam. Should I go ahead and give it a try or am I being too optimistic?

Unfortunetly I bought the car like this, so I don't know how long it's been like this nor what type internal parts were used.

Also..... could it possibly be a broken ring(s) contributing to piston slap?

MrBill

Have you tried a makeshift stethescope to narrow down the source of the tick? If not find yourself some sort of long metal rod, stick one end on your ear and probe around the engine with the other end...including the block. You'll be amazed how easy you can pinpoint whether it's top or bottom end.

AJ_92RS

Yes I have.

I used a really long prybar/screwdriver. I just put my ear on it.

I put it on every one of the intake runners, header tubes, on the base of the intake, on the side of the block under the car, even on the carb itself just to make sure it wasn't a float rattling around.

All I hear are normal sounds from the valves opening and closing.

I guess I may just pull the engine apart and start looking. Process of elimination I guess.

jamesbob02

I've got the same kind of thing. No idea what it is - definitely not the rocker, though. Hope you figure it out! (Me too lol)

Take this opportunity to rebuild the engine or put in a stroker kit!

I'm assuming the tick was there before you put in the lifters and the cam?

I posted about this and somebody mentioned that it could be a bent pushrod or worn valve guides. I have no idea though. Good luck solving it.

MrBill

Did you check around the bell housing area? Loose TC-flexplate bolts can cause a ticking/knocking sound (assuming yours is an auto).

AJ_92RS

It's certainly frustrating. I can tell you that.

James,

I haven't installed the new cam and lifters. I just have them because I figured that's what the noise was from.

I've been through the rockers about 3 times. Backing off until they clank around, snug them up 'til they stop, then another 1/2 turn.

Mr. Bill,

Yes it's an automatic and that's a good possibility. I never thought of that. It would kind of make sense except wouldn't it be as fast as the RPM? It does seem to move around the engine compartment, and sounds like it's coming more from the Right Rear of the block.

Not doubting that it maybe either torque converter bolts or flexplate bolts. It's just got me so frustrated I keep second guessing.

Maybe that's part of my problem.

Thanks for the help guys.

MrBill

Well I think you should be able to pinpoint to some degree with the "stethescope". I would be hesitant to start replacing stuff until I could do that.

I had a similar issue with my vette. A very slight "ticking" sound that I couldn't track down on the top end. When I stuck my "stethescope" on the side of the block though it was very evident that it was a bottom end problem. Turns out some bonehead installed a .010" under crank but used standard rod and main bearings.

Keep probing around, when you find the general area you'll know it.

dimented24x7

iTrader: (2)

id definatly check teh flexplate bolts. I had a problem jsut like that when all the bolts began to back out.

Air_Adam

Exhaust leak? Check your manifold gaskets and torque specs.

AJ_92RS

I know it's not an exhaust leak. I know that sound.

Nobody has really answered my question about whether it could actually be piston slap or rod knock.

Does piston slap happen only on the cycles with cylinder pressure, or all the time? Same with a rod knock.

Do either of those normally go away at higher RPM? Or stay all the time?

Does a broken piston ring make the piston slap around?

I've heard everything else short of the flexplate/TC bolts. That's something I never thought of.

I do appreciate everyone's input though. I just don't want you guys wasting your time telling me what it might be when I know it isn't those things. Understand?

It's a deep sound, not a typical lifter tick, broken spring, exhaust leak sound.