Engine is tapping bad, but not all the time, how do i adjust valves? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

>X< · 10-23-2002, 10:43 PM

my engine (350 pontiac with at least 200 thou miles on it) taps real bad at 50 or over, does this all the time, but now it taps when i take a right turn, not a right angle tun, but a gradual right curve, i taps very bad, but not on left, so that meant it must just be one side, also when i get on it, it taps bad right before it shifts, i've never taken off the valve covers before, but would like to learn how to adjust valves, since it might be this, i guess. what do i lok for to be wrong when i take the covers of? thanks, sean

bigjimzlll · 10-23-2002, 10:54 PM

Hi...it dosen't sound like lifters rattling to me...have you checked your oil?????? if its a little low then when you turn the oil pick up wont be in the oil...then the tappets will make noise... I hate to even mention the fact that might be a rod a knockin...check the oil first...if its low try alittle 20-50w in it

Hooter · 10-23-2002, 11:00 PM

well if you want to know how to adjust the valves here is how i do it. I will start the motor throw on the custom valve cover i made so i can have access to the rocker bolts and not have oil get all over the place. 1. Back off the valve until it starts going clickity click 2 slowly tighten it until it gets quiet 3 tighten it another 1/4 turn

Jwill41 · 10-23-2002, 11:08 PM

i have always used 3/4 turn total but 1/4 at a time.

JimKshortstep4x4 · 10-24-2002, 07:34 AM

I adjust valves as Hooter does, but I install the little clips on the rockers to keep the oil from squirting over the top of the cut off valve cover. I have done the 1/4 turn tight as Hooter does for a lot of years and it works well over time.

The rattle you hear could be lifters or possibly rods. The lifters are the first to rattle when oil pressure drops off. If the engine oil is ok, it is possible that the pickup screen is set too high in the pan or has dropped off. When you go around a curve the oil can move away from the oil pump pickup and what you describe sounds like a loss of oil pressure.

Jim

meathead95 · 10-24-2002, 07:51 AM

I would check the exhaust manifolds real quick before I took the valve covers off. you could have a loose manifold. maybe when you go around a curve your truck twist makes it leak a little more my v-8 s-10 leaks like you said all the time I am constantly tightening the headers on it. I may be wrong but its worth a shot.

Frank_Zeller · 10-24-2002, 08:45 AM

The stock Pontiac rocker arm set up is non adjustable. Just torque the nuts to around 25 foot pounds. You can convert to chevy bb studs and polylocks if you have screw in studs to make the valve train adjustable. Also try running plus one quart of oil to see if the problem goes away. I do this on my 455 to insure I have enough oil at high rpm. No ill effects.

I would be interested in you frame to motor mounts if you ever deside to go back to a Chevy motor.

>X< · 10-24-2002, 03:20 PM

bigjim- i check the oil weekly, so i dont think its that, but it might be the pickup thing, but why does it only do it on right turns? if it is this wouldnt it do it on both right and left? thanks, sean

meathead95-it cant be the bolts because if i let off the gas it stops, so its motor related, thanks for guess tough

Frank Zeller- i'll take he cocvers off today if i get off work. my motor mounts look homade, and i'm selling my truck when i finish painting it, but if i o decide to put eth 454 in that truck, i'll save your name for the mounts, but i dont think there worth anything. i can takesome pics if yo uwant though

meathead95 · 10-24-2002, 03:24 PM

when you let out of the gas on my s-10 it gets alot quieter too. less exhaust pressure, less exhaust leak. just a thought though. your description sounded just like my sh*tty headers on my s-10

>X< · 10-24-2002, 03:56 PM

i'm gonna go outside right now and check ex. manifold bolts, and check rockers later, truck wouldnt start by the way, been having problems with battery and alternator, i think alernator isnt bog enougt for battery. thanks man

10-23-2002, 10:43 PM	#1
>X< registered IWATA user Join Date: Feb 2002 Location: Baton Rouge Posts: 4,481	Engine is tapping bad, but not all the time, how do i adjust rockers? my engine (350 pontiac with at least 200 thou miles on it) taps real bad at 50 or over, does this all the time, but now it taps when i take a right turn, not a right angle tun, but a gradual right curve, i taps very bad, but not on left, so that meant it must just be one side, also when i get on it, it taps bad right before it shifts, i've never taken off the valve covers before, but would like to learn how to adjust valves, since it might be this, i guess. what do i lok for to be wrong when i take the covers of? thanks, sean __________________ -'63 Ford Fairlane 500 coupe, v8, auto, faded and rusty. awaiting built roller 302 and some flat black -'99 Honda Prelude. vtech/5spd. no pipe, no intake, bone stock. awaiting new top end. -01 GMC Yukon SLT 5.3 dented and scratched with a noisy tranny. Take off that Von Dutch hat before i stab you with a 000 Mack. Last edited by >X<; 10-24-2002 at 03:13 PM.

10-23-2002, 10:54 PM	#2
bigjimzlll Senior Member Join Date: Dec 2001 Location: Redding,CA...USA Posts: 4,736	Hi...it dosen't sound like lifters rattling to me...have you checked your oil?????? if its a little low then when you turn the oil pick up wont be in the oil...then the tappets will make noise... I hate to even mention the fact that might be a rod a knockin...check the oil first...if its low try alittle 20-50w in it __________________ It's called "drag racing" if they called it "tic..tic..WHAM!..BANG! F*&K!!!", they'd have to keep the magazines under the counter with the other men's publications click the clicky to join the site.... http://67-72chevytrucks.com/vboard/payments.php 67 lwb..first hotrod in 25 years..540 best ET is 9.45 @ 141.44 Anderson,CA

10-23-2002, 11:00 PM	#3
Hooter My other Love Join Date: Aug 2001 Location: Castlegar B.C. Canada Posts: 4,085	well if you want to know how to adjust the valves here is how i do it. I will start the motor throw on the custom valve cover i made so i can have access to the rocker bolts and not have oil get all over the place. 1. Back off the valve until it starts going clickity click 2 slowly tighten it until it gets quiet 3 tighten it another 1/4 turn __________________ Castlegar B.C.The great white North (Canada Eh!) Hooter_5@hotmail.com First generation Monte Carlo club pictures of my life

10-23-2002, 11:08 PM	#4
Jwill41 Registered User Join Date: Aug 2002 Location: Farmers Branch, Tx Posts: 1,009	i have always used 3/4 turn total but 1/4 at a time. __________________ http://www.picturetrail.com/jwill41 67 1/2 ton GMC short step side 68 1/2 ton Chevy long fleet side 72 1/2 ton Chevy Suburban 99 1/2 ton Chevy Suburban founder (and only member) of the primer/clearcoat club

10-24-2002, 07:51 AM	#6
meathead95 computer illiterate Join Date: Jan 2001 Location: Des Moines, IA Posts: 6,440	I would check the exhaust manifolds real quick before I took the valve covers off. you could have a loose manifold. maybe when you go around a curve your truck twist makes it leak a little more my v-8 s-10 leaks like you said all the time I am constantly tightening the headers on it. I may be wrong but its worth a shot. __________________ 72 2wd blazer 72 swb 4x4

10-24-2002, 07:34 AM	#5
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	I adjust valves as Hooter does, but I install the little clips on the rockers to keep the oil from squirting over the top of the cut off valve cover. I have done the 1/4 turn tight as Hooter does for a lot of years and it works well over time. The rattle you hear could be lifters or possibly rods. The lifters are the first to rattle when oil pressure drops off. If the engine oil is ok, it is possible that the pickup screen is set too high in the pan or has dropped off. When you go around a curve the oil can move away from the oil pump pickup and what you describe sounds like a loss of oil pressure. Jim

10-24-2002, 08:45 AM	#7
Frank_Zeller Registered User Join Date: Jun 2001 Location: Austin, Texas Posts: 796	The stock Pontiac rocker arm set up is non adjustable. Just torque the nuts to around 25 foot pounds. You can convert to chevy bb studs and polylocks if you have screw in studs to make the valve train adjustable. Also try running plus one quart of oil to see if the problem goes away. I do this on my 455 to insure I have enough oil at high rpm. No ill effects. I would be interested in you frame to motor mounts if you ever deside to go back to a Chevy motor. __________________ 69 SWB C/10 5-6 drop 700R4 69 Firebird Convert 455 4 spd 70 Torino GT Convert Austin-Texas Last edited by Frank_Zeller; 10-24-2002 at 08:47 AM.

10-24-2002, 03:20 PM	#8
>X< registered IWATA user Join Date: Feb 2002 Location: Baton Rouge Posts: 4,481	bigjim- i check the oil weekly, so i dont think its that, but it might be the pickup thing, but why does it only do it on right turns? if it is this wouldnt it do it on both right and left? thanks, sean meathead95-it cant be the bolts because if i let off the gas it stops, so its motor related, thanks for guess tough Frank Zeller- i'll take he cocvers off today if i get off work. my motor mounts look homade, and i'm selling my truck when i finish painting it, but if i o decide to put eth 454 in that truck, i'll save your name for the mounts, but i dont think there worth anything. i can takesome pics if yo uwant though __________________ -'63 Ford Fairlane 500 coupe, v8, auto, faded and rusty. awaiting built roller 302 and some flat black -'99 Honda Prelude. vtech/5spd. no pipe, no intake, bone stock. awaiting new top end. -01 GMC Yukon SLT 5.3 dented and scratched with a noisy tranny. Take off that Von Dutch hat before i stab you with a 000 Mack.

10-24-2002, 03:24 PM	#9
meathead95 computer illiterate Join Date: Jan 2001 Location: Des Moines, IA Posts: 6,440	when you let out of the gas on my s-10 it gets alot quieter too. less exhaust pressure, less exhaust leak. just a thought though. your description sounded just like my sh*tty headers on my s-10 __________________ 72 2wd blazer 72 swb 4x4

10-24-2002, 03:56 PM	#10
>X< registered IWATA user Join Date: Feb 2002 Location: Baton Rouge Posts: 4,481	i'm gonna go outside right now and check ex. manifold bolts, and check rockers later, truck wouldnt start by the way, been having problems with battery and alternator, i think alernator isnt bog enougt for battery. thanks man __________________ -'63 Ford Fairlane 500 coupe, v8, auto, faded and rusty. awaiting built roller 302 and some flat black -'99 Honda Prelude. vtech/5spd. no pipe, no intake, bone stock. awaiting new top end. -01 GMC Yukon SLT 5.3 dented and scratched with a noisy tranny. Take off that Von Dutch hat before i stab you with a 000 Mack.

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