tapping noise in top of motor

[rockyman]

1978 inline 6cyl 250 chevy motor . would like to know the proper way to adjust valves or lifters .thanks

 

[fishrdan]

Re: tapping noise in top of motor

Or if you want to do it the messy way,,, warm up the engine, remove the valve cover, while the engine is running back off each rocker (1 at a time) until it starts to clatter, slowly tighten back down until it "just" stops ticking and then slowly tighten it another 3/4 turn,,, clean off the oil that splattered all over the place

On the cold adjustment Bubba was talking about, I was taught to roll the push rod lightly in-between 2 fingers while tightening the nut and when you feel slight drag on the pushrod, you are at zero lash. Then slowly turn the nut another 3/4 turn.

Why do you need to adjust the lifters? Noisy? Could be a dirty/sticky or bad lifter(s)

(EDIT, I should have said slight resistance or drag on the push rod, not the puch rod stopping)

 

[Don S]

Re: tapping noise in top of motor

Hydraulic lifters do not get out of adjustent. They get suck or leaky, because of dirt or just plain worn out. But, they are self adjusting so readjusting is not fixing anything, only temporarily making it quieter.
Are you sure the oil level isn't over full? That would cause noisy lifters because the crankshaft hits the oil and aireates it. Aireated oil will not keep a lifter pumped up.

 

[fishrdan]

Re: tapping noise in top of motor

Yeah, 6 of 1, half dozen of the other

I edited my post since you don't want the spinning of the push rod to "stop", only to feel some drag on the spinning of the push rod. If it stops,,, you're too tight and past zero lash.

 

[rockyman]

Re: tapping noise in top of motor

does the L6 have hydrolic lifters

 

[Don S]

Re: tapping noise in top of motor

Yes

 

[rockyman]

Re: tapping noise in top of motor

at idle when i first crank it up cold oil presure goes to the half way point ,my gauge has four marks after an hour or so of stop and go at idle it stays on the first mark but as more throttle is given it goes back to the half way point again and staysn there,also i must say when it warms up it dont tap as loud . how do you change hydraulic lifters

 

[Don S]

Re: tapping noise in top of motor

If you have to ask "How", then the only thing you can do is follow the OEM service manual.
Here is a link to the manual downloads. Pickout the one for the year you have.

http://forums.iboats.com/showthread.php?t=251571

 

[rockyman]

Re: tapping noise in top of motor

what type oil should be used for this motor

 

[DJ]

Re: tapping noise in top of motor

Most use a straight 30.

I agree that if you have "clattering" rockers, you may have other issues.

Unless the adjustment is WAY OUT, the lifters should take up the slack.

Of course, it doesn't hurt to make sure the adjustments are at least close. It will only cost you a gasket.

 

[chiefalen]

Re: tapping noise in top of motor

Ok i stayed away from this post cause you have some great minds already posted reply's.

Have you done a compression check on this motor ?

First thing i would have done. At the same time you get to look at the plugs.

Just my 2 cents.

Good luck !

 

[dan t.]

Re: tapping noise in top of motor

ok,my two bits worth. a noisey rocker can be a number of things, worn swivel ball, worn or bent push rod, worn valve guide, worn end on the rocker or top of valve stem, broken valve spring. check them all. K D tools make clip on plugs for the oil hole in the rocker so it doesnt spray so bad. another way is to loosen the rocker till it ticks, tighten to quiet, then go to the next one until all are at 0 lash shut off the motor, then turn down 3/4 of a turn.

 

[rockyman]

Re: tapping noise in top of motor

i have been putting 10-w30 gtx gastro oil in there, could i have caused any damage, it didnt start tapping untill i changed the oil at the beggining of summer,

 

[Don S]

Re: tapping noise in top of motor

Now, we get the Rest of the Story as Paul Harvey would say.

it didnt start tapping untill i changed the oil at the beggining of summer,

Since it didn't have a problem till you changed the oil, that statement alone should give you a hint of the problem.
Put a new filter with a good quality straight 30W oil in it and see what happens.

 

[chiefalen]

Re: tapping noise in top of motor

1978 motor, i still say do a compression check and post the numbers, please.

 

[rockyman]

Re: tapping noise in top of motor

was wandering if 1984 v6 mercruiser has hydraulic lifters as well because my friend has tapping in his top end,if i have to start a new thread for this let me know, this is the only question that will be ask concerning his motor, thanks

 

[Don S]

Re: tapping noise in top of motor

ALL Mercruiser Chevy gas engines have hytraulic lifters. Did your friend use the same oil as you did ??????????

 

[rockyman]

Re: tapping noise in top of motor

yes don he sure did , could it have caused any damage

 

[Bondo]

Re: tapping noise in top of motor

yes don he sure did , could it have caused any damage

Ayuh,.... Probably Not,... But,.. You've used up your Questions, til you start providing some Answers....

 

[rockyman]

Re: tapping noise in top of motor

okay bondo you will have some ansewers by the weekend but in the meantime thanks for all of you guys help ,its really been very helpful and most of all a big learning experience.