New lifters - old cam?

[RossGN]

Bought the car on Ebay last year (I know). Cant find the folder that came with the car, but I seem to remember paperwork showing an engine rebuild 6k ago. Car sounds great at idle and for the first minute of cruise, what I am pretty sure is a lifter starts acting up. It is the typical clickety clickety. Have had a GN with bad rod bearing before...nothing like that. After your pull into the drive way, the noise goes away. Even from idle and brief revving reveal no noise. If you hold at 2k or 3k, the noise will come back. I have the intake off now (only took me 8 months to get around to doing it). Cam lobes look good...no sign of wiping. I have a new set of HT969 lifters and am tempted to just replace them all, but have had wiped a cam lobe before with new lifters on old cam. suggestions?

 

[earlbrown]

When you say the cam lobes ''looked good'', did you have a dial indicator on the lobes backing up your observation? If you've got a lifter that won't be pumped up with the engine revved up, it's most likely not going to pump up at idle oil pressure. Have you verified you don't have any rocker shaft buttons broken (or rocker shafts themselves)?

Since you've already got the intake off, I'd pull the lifters out one at a time and spin them on a piece of plate glass. If any of them have a convex bottom and don't Weeble-Wobble, go ahead and start drinking....

 

[RossGN]

Will do....thanks Earl.

 

[87chrisss]

Will do....thanks Earl.

Noises always seem to haunt some of us, im also a fanatic of noises.. "Do you hear that" everyone thinks im crazy, few things i have noticed that sounds similar to a tick tick or click that you stated, driver side header with hairline crack, or a failing header gasket on either side. I have also noticed are engines are usually noisey like a sewing machine. If a cam lobe was worn or a lifter were bad you would have vacuum inconsistency lack of power and metal in the oil, probably have some bad poppin on WOT. Overall if your engine has decent oil pressure and there is a way to test it with RPM Gnttype has the specs on where your oil pressure should be with rpm / temp.

I would also check the lifters like Earl stated since its all apart already. I guess we all have to start learning if it aint broke dont fix it and pump up the music so you cant find any noises, lol ive started out with a noise and ended up with a new engine multiple times when it was perfectly fine

 

[RossGN]

Thanks Chris.....have had header cracks before on other GNs I have owned and this is distinctively different sound....almost a "double click". Will check all the lifter faces. Thought about disassembling each lifter, but wouldn't know what to look for other than trash

 

[RossGN]

Also....this is not a small tick.....this makes you worry that the pushrod might shoot through the valve cover if you really wound it up

 

[87chrisss]

Also....this is not a small tick.....this makes you worry that the pushrod might shoot through the valve cover if you really wound it up

Check the actual rocker shaft for crack, i also had a tick one time and noticed that the orange alignment plug had came loose on a rocker arm.
(Cant think of the name of the orange plug) what holds the rocker arm in place

 

[earlbrown]

^rocker arm button

 

[Pronto]

Ya, that plastic button was a brilliant idea.

 

[ZNix]

Ya, that plastic button was a brilliant idea.

LOL, right?

Sounds like my car did when I broke a rocker shaft... Check them for any little cracks or loose bolts?

 

[RossGN]

Rocker shafts look good...rocker buttons look good. all pushrods measure right at 8-11/16". Lifters feel the same on plate glass as the new 969s. Should I just replace the lifters and go for it, or should I check something else? If I install the new lifters...what is the best assembly lube? Should I get 4 quarts of break-in oil or would the comp cams additive suffice?

 

[hensleyt]

when you pulled the rocker shaft ,did all the faces on the rocker arms that touch the valve stem look alike? and all the stems look good (no bur around the edge of the stem) If you got valve train noise you should see it on stem and rocker

 

[RossGN]

Rocker surfaces all look and feel fun, BUT just discovered the pushrod for the #5 intake valve was stopped up. Cleared it with piano wire. Wonder if that could be the culprit?

 

[RossGN]

Update. ...replaced lifters and cleared blockage in one pushrod. No more noise after warm up.

 

[Pronto]

Nice to see you fixed it without much trouble.