Pushrod question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

784X4GUY · 12-22-2003, 05:29 PM

Hey yall,

Ive got a popping sound in my motor...and some people have told me that i might have a bent pushrod cause i just replaced the cam lifters timing chain and forgot to replace the pushrods...yeah yeah i know ima idiot...but do yall think a bent pushrod could be causing the popping sound coming out of the #7 cylinder exhaust port area...ive got headers and because of that pop my header gasket keeps blowing right there...any help would be greatly appreciated...

Thanks, Mike

784X4GUY · 12-22-2003, 08:13 PM

well I did adjust all of them the way mike ervin described on his web page no tighter and no looser...i really dont understand why its making that sound...

Tom · 12-22-2003, 08:35 PM

Dont be so hard on yourself. Changing pushrods is not normal and deffenatley not standerd when switching cam+lifters. I agree its the valves not adjustedly correctly yet.

EDIT: take a valve cover off and inspect all the pushrods. If they are all ok, find the ticking noise with the motor running [quickly or else oil is going places

] and adjust that valve until it goes away.

MylilBowTie · 12-23-2003, 09:13 AM

Setting the idle down will help to adjust the rockers while the engine is running. So there isn't as much oil flying around. You also have to take your time when you adjust the lifters. Adjust them one by one then wait a couple of seconds for it to change.

Have you done a compression check yet? For some reason I think it could be valve related. Like a burnt valve or something like that. If its not the valve lash. I think its to early to see a collapsed lifter or concave lifter. Compression test will help out a little bit if you are able to do it. Vacuum gauge wouldnt hurt either.

784X4GUY · 12-23-2003, 05:17 PM

yeah, thats the same thing i thought. I also took the heads off and took them to a machine shop and had them check and then cleaned. He did a vacuum check on all the valves and all valves checked out good. He said there wasnt anything wrong with the heads. Im completely lost and dont know where to go from here. Any help would be appreciated.

Mike

*1972C10* · 01-02-2004, 03:47 AM

Did you break in the cam ?
Could be insuficcent lube up and one lobe wore flat or got one too tight and wore one flat.. you could possibly rent a mic to check the valve lift Might see if autozone has them Im sure you can find a cheap one If not look at pawnshops for a used one because machinsts tools arent cheap. but first try the compresion test test each cylinder document it and see what the variance is if one has alot less compression than the rest that cylinder is the culprit ..

chevyfan420 · 01-02-2004, 11:49 AM

your exhuast valve is probably overtightened. with it running, back off the locking nut 'til the rocker starts to chatter. tighten 1/4 turn past the point it stops chattering. good luck

78chevstepside · 01-02-2004, 12:22 PM

there is a possibillity a lifter never turned upon installing the new cam. all the adjusting in the world wount fix this. I had this happen recently. I pull the intake and found a ground up lifter .

12-22-2003, 05:29 PM	#1
784X4GUY Did someone say MUD? Join Date: Aug 2003 Location: Pullman,WA Posts: 1,089	Pushrod question Hey yall, Ive got a popping sound in my motor...and some people have told me that i might have a bent pushrod cause i just replaced the cam lifters timing chain and forgot to replace the pushrods...yeah yeah i know ima idiot...but do yall think a bent pushrod could be causing the popping sound coming out of the #7 cylinder exhaust port area...ive got headers and because of that pop my header gasket keeps blowing right there...any help would be greatly appreciated... Thanks, Mike __________________ Im in the market guys...so keep ya eyes peeled -------------------- Mini trucks are for guys who cant get it up!

12-22-2003, 08:13 PM	#2
784X4GUY Did someone say MUD? Join Date: Aug 2003 Location: Pullman,WA Posts: 1,089	well I did adjust all of them the way mike ervin described on his web page no tighter and no looser...i really dont understand why its making that sound... __________________ Im in the market guys...so keep ya eyes peeled -------------------- Mini trucks are for guys who cant get it up!

12-22-2003, 08:35 PM	#3
Tom driving is in my blood Join Date: Dec 1999 Location: Mesa AZ Posts: 5,748	Dont be so hard on yourself. Changing pushrods is not normal and deffenatley not standerd when switching cam+lifters. I agree its the valves not adjustedly correctly yet. EDIT: take a valve cover off and inspect all the pushrods. If they are all ok, find the ticking noise with the motor running [quickly or else oil is going places ] and adjust that valve until it goes away. __________________ -78 c10 short/step: 388cid, M20, 5/5 drop, lots more. Playtoy and first vehicle. -98 c1500 x-cab: 5.7L, 17" rims, 5/6 drop, flowmaster, helper bags,NBS rear disk brakes. -02 Suburban 4x4: leveled front -CBR600F4i, CBR600RR, CBR1000RR, and standup skis DISCLAIMER: I cant spell for the life of me. Last edited by Tom; 12-22-2003 at 08:37 PM.

12-23-2003, 09:13 AM	#4
MylilBowTie Right turn Clyde Join Date: Nov 2002 Location: Cincinnati, Ohio Posts: 2,911	Setting the idle down will help to adjust the rockers while the engine is running. So there isn't as much oil flying around. You also have to take your time when you adjust the lifters. Adjust them one by one then wait a couple of seconds for it to change. Have you done a compression check yet? For some reason I think it could be valve related. Like a burnt valve or something like that. If its not the valve lash. I think its to early to see a collapsed lifter or concave lifter. Compression test will help out a little bit if you are able to do it. Vacuum gauge wouldnt hurt either. __________________ 1974 C25 LWB: 454 4bbl Carb / TH400 / 3.73 1992 Camaro RS 305 TBI Last edited by MylilBowTie; 12-23-2003 at 09:16 AM.

12-23-2003, 05:17 PM	#5
784X4GUY Did someone say MUD? Join Date: Aug 2003 Location: Pullman,WA Posts: 1,089	yeah, thats the same thing i thought. I also took the heads off and took them to a machine shop and had them check and then cleaned. He did a vacuum check on all the valves and all valves checked out good. He said there wasnt anything wrong with the heads. Im completely lost and dont know where to go from here. Any help would be appreciated. Mike __________________ Im in the market guys...so keep ya eyes peeled -------------------- Mini trucks are for guys who cant get it up!

01-02-2004, 03:47 AM	#6
1972C10 Account Suspended Join Date: Dec 2003 Location: Texas Posts: 2,686	Did you break in the cam ? Could be insuficcent lube up and one lobe wore flat or got one too tight and wore one flat.. you could possibly rent a mic to check the valve lift Might see if autozone has them Im sure you can find a cheap one If not look at pawnshops for a used one because machinsts tools arent cheap. but first try the compresion test test each cylinder document it and see what the variance is if one has alot less compression than the rest that cylinder is the culprit ..

01-02-2004, 11:49 AM	#7
chevyfan420 Registered User Join Date: Nov 2003 Location: Ancaster, Ontario, Canada eh Posts: 95	your exhuast valve is probably overtightened. with it running, back off the locking nut 'til the rocker starts to chatter. tighten 1/4 turn past the point it stops chattering. good luck __________________ 80 Chevy K10 350/350turbo 86 Chevy 1/2 ton shorty project truck 79 Chevy 1/2ton 350/350turbo not much to look at... *Retired* 97 Chevy C1500 4.3/5 speed.....daily driver

01-02-2004, 12:22 PM	#8
78chevstepside Registered User Join Date: Nov 2002 Location: lacenter, washington Posts: 718	there is a possibillity a lifter never turned upon installing the new cam. all the adjusting in the world wount fix this. I had this happen recently. I pull the intake and found a ground up lifter .



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