dimented24x7

iTrader: (2)

Ever since I put my new engine together, there has been one lifter that has an intermittent RPM/temperature dependant tick. No ammount of adjusting will cure it. Its really damn annoying. What would be the most likely cause? A scored valve or valve seat in the lifter? Mis-sized plunger or bore?

I was thinking of trying to rebuild it with parts from a new lifter to see if the tick can be stopped.

Damon

Don't play mix-n-match. Replace the lifter if you suspect it's bad.

Also check for a worn valve guide on that one. Lots of times they don't tick until things warm up. Ditto a worn out lifter bore.

tom3

Take a look at the top of the valve stem too. Some times the tip will wear off to one side, the rocker will run a bit crooked at times and the lifter can't keep up with it.

dimented24x7

iTrader: (2)

Its a flat tappet, so I was thinking of getting the exact same set of lifters that it currently has to rebuild one, assuming its actually not something wrong with the body of the lifter itself.

Is it safe to break in a flat tappet cam with a new lifter? Some have the opinion that you run the risk of wiping a lobe during a second break-in.

The block and heads are pretty much new. I cant see it already having a worn bore or valve guide yet. It also has lash caps, so wear at the tip should not be an issue.

DeathStarr89

iTrader: (1)

Yes, you can break a new lifter in to a used flat tappet cam. Just make sure to have some good zinc additive in the oil.


If you pull the valve cover with the engine running, how is the oil flow out of the pushrod that's on the suspected bad lifter?

five7kid

iTrader: (14)

There's a difference between "ticking" and "collapsed".

How much of a turn down did you use when you adjusted them? I've had a few lifters that would not quiet down with 1/4 or 1/2 turn, but are completely silent at 1 turn down.

After adjustment, the next most common cause of ticking is dirt. Often disassembly, thorough cleaning (non-abrasive), lube & reassembly will cure that.

Don't mix parts from different lifters.

Put ARP thread lube on the bottom of the lifter and as much of the lobe as you can reach if putting a new lifter on an old cam.

F-BIRD'88

What is the engine idle rpm? What is the engine oil pressure at that idle speed? What is the engine oil pressure checked@2000rpm and all warmed up? (ya it matters) What is the engine water temp at idle when all warmed up and makes lifter noise.
Why does a street motor with a hyd flat tappet cam need lash caps?

If after trying more lifter preload adjustment and a higher viscosity oil 15w-40, remove the lifter and inspect the face. If it has a slight crown face, install a new lifter on the lobe. You can hold the lifter against another lifters body or face to see the crown. If the lifter face is flat replace the cam and all lifters with new. (you may even get warranty. If you are going to claim a warrranty replacement on the cam and lifters 'cause one is wearing the face and/or making noise now is the time) Do not mix internal lifter parts.

Since the OEM's have stopped using flat tappet cams and lifters in any of their production motors, the quality of flat tappet lifters has degraded.
Ya get more bad ones in a bunch with fubared internals that make noise at idle.

dimented24x7

iTrader: (2)

See below in bold...

dimented24x7

iTrader: (2)

Another thought occured to me. Since Im going over to a later PCM at some point, and can run an external 24x crank trigger, I wont need the crappy plastic vortec timing chain cover. So, I can go over to my retro roller kit. Are there any potential relatively 'long' term issues leaving it like it is? It only seems to really be an issue at low engine speeds.

I dont think its wiping a lobe. Its been run like this for a while now, and it hasn't gotten any worse.

F-BIRD'88

240 degrees is way toooooooo hot. No wonder its ticking. You need to get that under control.
Apparently GM sells the good HD "taxi" hyd lifters with the special foot. Again. I don't have a part number for them. The foot/face of the lifter body is made of a special steel.

dimented24x7

iTrader: (2)

the heat issue wasn't by choice. I grounded out and took the airdam clean off.

Those are the ones I had before, with the spun-welded hardened foot on the bottom. Theyre like $90 or so from summit, and are much quieter than any aftermarket lifter Ive used up to this point. They also seem to be indestructable. My last engine had the front cam bearing go bad, which caused the front of the cam to sag, and teh lifters at the front to ride up onto and over the edge of the cam lobes. They actually survived like that for a while. Now, how come the aftermarket ones cant be that good?

dimented24x7

iTrader: (2)

Hmmm... It seems to have gone away on its own. I dont know whether to be happy, or concerned. Hopefully the lifter just managed to regurgitate whatever was holding the checkvalve open.

Im definitely thinking of running a solid roller next time around. The hydrolic lifters just dont seem to be that great with a more aggressive cam profile. Even with a new airdam/air deflector and reworked cooling system that now keeps the engine at 195 at all times, all the lifters still clatter at certain RPMs.