I hate my winter chevy ride! Its broke help

Big Bopper · 11-16-2003, 06:16 AM

hey guys long time ... I just put my soft top away (90GT) and bought a 96' chevy 4x4 with a 350 vortec auto,,,. I know chevy crap..it was cheap...lol...
Anyway it had this tick it sounded like a loud lifter or somethin' it would only tick when it was warm and only ticked when you let off the gas when your driving...Well the stupid thing is worse now...Now it's missing on a cylinder and backfires through the exhaust..? What the hell does that mean? A few friends have said "bent valve"..,"bent or broken pushrod"..,"broken valve spring".. ??????????
Could someone that actually knows what their talking about help me?( My beer swillin' chevy friends I don't trust)

Thanks eh...... Jolee.

RoadWarrior · 11-16-2003, 05:59 PM

Could be a dead lifter.

billheis · 11-16-2003, 10:37 PM

Sounds like you may have a worn rocker/pushrod. See if you can determine which side and pull that valve cover. The old chebys would clog up the two exhaust pushrods on either side of the heat riser port that goes into the intake and then no oil would go to the rockers. Check those middle ones first

rwhite65 · 11-17-2003, 05:30 AM

wouldn't a compression test help him narrow down to hopefully one cylinder?
Ryan

hemlock · 11-17-2003, 03:36 PM

Chevy's have always been notorious for lifter "tick". I wouldn't have thought twice about that. Since you are having a backfire problem, it definitely sounds like you are hanging the exhaust valve open at the time of ignition. You can rule out broken pushrod, since the valve wouldn't open at all. Bent is possible, but not probable since most of the high-revving Chevy's come with hardened pushrods. Hence, they will break before bending.

Does the exhaust have a strong scent of gas when this is happening? If so, it may not be a mechanical problem at all. You may have a dead cylinder electrically and you are pushing raw fuel into the "cats". Check the spark plugs to see if you have a wet or badly fouled plug. Also, if you are pushing fuel into the exhaust, you can just drive it at night, stop and check the color of the "cats". If they are glowing, you are definitely pushing raw fuel out the exhaust, which means that you have a plug, wire, or ignition problem. Fix that before you have to spend alot on new cats and O2 sensors.

If it is not that, I would recommend taking off the valve covers, pulling the coil wire and have one of your "Beer swilling Chevy friends" turn the car over while you watch the rockers go up and down. Take special notice of the valve stem heights (straight edge) to see if you have an exhaust valve hanging low all the time. Also, if this is a high-RPM/deceleration problem, look at all of the springs, inner and outer. You might have one broken and it is "floating". You wouldn't see it at idle, but definitely up above 4000 RPM and coming down from there.

FYI - When you are asking for help from people knowledgeable about Chevy's, try not to insult them at the same time. ;-)

Big Bopper · 11-17-2003, 09:49 PM

Thanks Hemlock ....,I'll pull the valve covers off and have a look and see if i have one exhaust valve hanging low all the time ...
I don't smell any gas at the exhaust...? I don't want to drive it because I was told that the pushrod might not be oiling that rocker and that might do more damage?? Is that possible?
I can't turn the engine over with both valve covers off because all the a/c stuff and serpintine belt have to come off...can I do it by hand? will that get the same effect?

P.S. I wasn't trying to insult anyone,it's just that all my friends drive chevys and they always sit around drinking when I'm working on my 5.0's telling me "stop wasting your time with that ford crap".., never helping because it's a "FORD"
So I acually don't "trust" them, they are Always pulling my leg because I don't Know much ...yet...

Thanks again to "Roadwarrior","rwhite65" and "Hemlock"

Big Bopper.

Big Bopper · 11-17-2003, 09:51 PM

Sorry and to "billheis"

hemlock · 11-18-2003, 04:37 AM

Hi Big Bopper --

No apologies necessary. I was pulling your leg. I am an American muscle car fan. I hold no allegiance to any particular maker. Ford, Chevy or Mopar is all good. Your buddies are lazy, but that is not indicative of any particular car owner. I was more of a Chevy guy back in the day because they are so much cheaper to get parts (trade and purchase) plus the parts work for so many different year applications. If you got the money, Mustang is a great car to build and make horsepower with.

Absolutely, it is possible that the lifter/pushrod is not oiling the rocker. The lifters are hydraulic and can wear out. The pushrod however would have to be very bent to stop the flow of oil. When you get in there, turn the engine by hand and put each exhaust valve to its most closed position (individually of course). If you have a bad lifter, it will either be locked solid or so soft that you can push it back down by hand (push the pushrod side of the rocker). If it hasn't been run in sometime, then all of them may have bleed down and be soft. You may have to run it for a couple minutes to pump them up with oil and make them hard enough to do that test. If it locked solid, you will know that without running the engine first. This is highly probable since you describe a hanging exhaust valve.

Something else to check since you are already in there would be if there is a rocker that is extremely sloppy. When the tension is off, all of them will wiggle a little bit, but if you can actually turn it side to side and touch the head with the pushrod, you may have a bent pushrod like the others mentioned. If you can actually get the pushrod out of the cup on the rocker, it more likely that the lifter is dead. I don't think that is the problem since you sound like you are hanging a valve open, not closed, but it is something to check. It is not a fun job, so you might as well check everything you can while you are in there.

Turning the engine by hand is definitely an option to see the valves work, however everything happens so slowly that you might not recognize any abnormalities. Plus you probably won't be able to turn it yourself and watch everything at the same time. If you do turn it by hand, do yourself a favor and pull the plugs to release the compression. The way I have done it in the past is purchase one of those cheap remote start switches that you can hook to solenoid and watch from the engine compartment while you let the starter do the work. Just remember to pull the coil wire off so that it doesn't start on you.

Sorry about being so wordy with these replies. I just wanted to be as specific as possible. Let me know how it goes.

Thanks,
hemlock

Big Bopper · 11-18-2003, 04:29 PM

Hey Hemlock.... This may be a dumb question but...How will I know if it is "locked solid"? Do you mean the pushrod for the exhaust valve will be locked solid ..meaning it won't move or wiggle at all, no matter what the position of the motor is at ?

thanks for your time and patience... Jolee

hemlock · 11-19-2003, 07:55 PM

Hi Big Bopper --

You'll know if that's the case. A lifter is made up of the lifter body, spring, seal, cup and circlip (locks everything in the lifter body. If the spring inside of it broke and twisted, it will lock up the seal from being able to pump up and down to push oil up the push rod. It can also be solid in the bottom position with a broken spring.

Basically, it is the up and down that you are worried about with a locked lifter. You won't be able to push it down at all no matter what the position is. As a matter of fact, it is more than likely that the valve will be sitting open. Check with a straight edge if you can to see if it sitting low.

hemlock

Big Bopper · 11-20-2003, 10:25 PM

Hey Hemlock.,

I 've pulled one of the heads and i don't see anything wrong ....
all the pushrods are sraight as fare as I can tell..took both sides of the pushrods out all seem to be real good ends smooth not blocked ect...

All the valves on the head that I took (passenger side) off are in the closed position so ...I gueuss I'll take the other head off and check that one as well...

I hope I haven't overlooked something real simple...like a bad plug or ...... bad plug lead....I don't Know,... I'm losing my mind .... I just assumed because of the tick that developed recently...

Thanks for your advice Hemlock.

Big Bopper

11-16-2003, 06:16 AM	#1
Big Bopper Registered Member Join Date: Jun 2000 Location: Sechelt, B.C., Canada Posts: 200	I hate my winter chevy ride! Its broke help hey guys long time ... I just put my soft top away (90GT) and bought a 96' chevy 4x4 with a 350 vortec auto,,,. I know chevy crap..it was cheap...lol... Anyway it had this tick it sounded like a loud lifter or somethin' it would only tick when it was warm and only ticked when you let off the gas when your driving...Well the stupid thing is worse now...Now it's missing on a cylinder and backfires through the exhaust..? What the hell does that mean? A few friends have said "bent valve"..,"bent or broken pushrod"..,"broken valve spring".. ?????????? Could someone that actually knows what their talking about help me?( My beer swillin' chevy friends I don't trust) Thanks eh...... Jolee. __________________ 90' GT Drop-top, 88' 302,pulleys,full flowmasters (turndowns),Ported stock Intakes,twin flex-a-lites,Pro-5.0,3.55's,short belt,elctric water pump,timing bumped,taylor leads.(headers soon!)

11-16-2003, 05:59 PM	#2
RoadWarrior Registered Member Join Date: Apr 2000 Location: Edmonton,Alberta,Canada Posts: 317	Could be a dead lifter. __________________ Fast Company

11-16-2003, 10:37 PM	#3
billheis Registered Member Join Date: May 2001 Location: Fernandina Beach, FL 32034 Posts: 178	Sounds like you may have a worn rocker/pushrod. See if you can determine which side and pull that valve cover. The old chebys would clog up the two exhaust pushrods on either side of the heat riser port that goes into the intake and then no oil would go to the rockers. Check those middle ones first __________________ Bill Heiser 90 Convertable 5.0 LX, ported E7s w/ THumper valve job, TFS street, FR 65mm TB, B cam w/1.7 cobra rockers, kirban AFPR, Mac CAI, Mac Headers, off road h, 3 chamber flows, Crane ign. box, 3:73s, Art Carr AOD & 2600 converter

11-17-2003, 05:30 AM	#4
rwhite65 Ride Hard Join Date: Oct 2000 Location: Wyoming IL Posts: 1,094	wouldn't a compression test help him narrow down to hopefully one cylinder? Ryan __________________ 65 Fastback 91 roller 306, H/C/I AOD-Bauman, PI Stallion, 4.10's and traction loc 04 Grand Cherokee Freedom Edition 79 Ford F-250 4x4 - Restored

11-17-2003, 09:49 PM	#6
Big Bopper Registered Member Join Date: Jun 2000 Location: Sechelt, B.C., Canada Posts: 200	Thanks Hemlock ....,I'll pull the valve covers off and have a look and see if i have one exhaust valve hanging low all the time ... I don't smell any gas at the exhaust...? I don't want to drive it because I was told that the pushrod might not be oiling that rocker and that might do more damage?? Is that possible? I can't turn the engine over with both valve covers off because all the a/c stuff and serpintine belt have to come off...can I do it by hand? will that get the same effect? P.S. I wasn't trying to insult anyone,it's just that all my friends drive chevys and they always sit around drinking when I'm working on my 5.0's telling me "stop wasting your time with that ford crap".., never helping because it's a "FORD" So I acually don't "trust" them, they are Always pulling my leg because I don't Know much ...yet... Thanks again to "Roadwarrior","rwhite65" and "Hemlock" Big Bopper. __________________ 90' GT Drop-top, 88' 302,pulleys,full flowmasters (turndowns),Ported stock Intakes,twin flex-a-lites,Pro-5.0,3.55's,short belt,elctric water pump,timing bumped,taylor leads.(headers soon!)

11-17-2003, 03:36 PM	#5
hemlock Registered Member Join Date: Nov 2003 Posts: 3	Chevy's have always been notorious for lifter "tick". I wouldn't have thought twice about that. Since you are having a backfire problem, it definitely sounds like you are hanging the exhaust valve open at the time of ignition. You can rule out broken pushrod, since the valve wouldn't open at all. Bent is possible, but not probable since most of the high-revving Chevy's come with hardened pushrods. Hence, they will break before bending. Does the exhaust have a strong scent of gas when this is happening? If so, it may not be a mechanical problem at all. You may have a dead cylinder electrically and you are pushing raw fuel into the "cats". Check the spark plugs to see if you have a wet or badly fouled plug. Also, if you are pushing fuel into the exhaust, you can just drive it at night, stop and check the color of the "cats". If they are glowing, you are definitely pushing raw fuel out the exhaust, which means that you have a plug, wire, or ignition problem. Fix that before you have to spend alot on new cats and O2 sensors. If it is not that, I would recommend taking off the valve covers, pulling the coil wire and have one of your "Beer swilling Chevy friends" turn the car over while you watch the rockers go up and down. Take special notice of the valve stem heights (straight edge) to see if you have an exhaust valve hanging low all the time. Also, if this is a high-RPM/deceleration problem, look at all of the springs, inner and outer. You might have one broken and it is "floating". You wouldn't see it at idle, but definitely up above 4000 RPM and coming down from there. FYI - When you are asking for help from people knowledgeable about Chevy's, try not to insult them at the same time. ;-)

11-17-2003, 09:51 PM	#7
Big Bopper Registered Member Join Date: Jun 2000 Location: Sechelt, B.C., Canada Posts: 200	Sorry and to "billheis" __________________ 90' GT Drop-top, 88' 302,pulleys,full flowmasters (turndowns),Ported stock Intakes,twin flex-a-lites,Pro-5.0,3.55's,short belt,elctric water pump,timing bumped,taylor leads.(headers soon!)

11-18-2003, 04:37 AM	#8
hemlock Registered Member Join Date: Nov 2003 Posts: 3	Hi Big Bopper -- No apologies necessary. I was pulling your leg. I am an American muscle car fan. I hold no allegiance to any particular maker. Ford, Chevy or Mopar is all good. Your buddies are lazy, but that is not indicative of any particular car owner. I was more of a Chevy guy back in the day because they are so much cheaper to get parts (trade and purchase) plus the parts work for so many different year applications. If you got the money, Mustang is a great car to build and make horsepower with. Absolutely, it is possible that the lifter/pushrod is not oiling the rocker. The lifters are hydraulic and can wear out. The pushrod however would have to be very bent to stop the flow of oil. When you get in there, turn the engine by hand and put each exhaust valve to its most closed position (individually of course). If you have a bad lifter, it will either be locked solid or so soft that you can push it back down by hand (push the pushrod side of the rocker). If it hasn't been run in sometime, then all of them may have bleed down and be soft. You may have to run it for a couple minutes to pump them up with oil and make them hard enough to do that test. If it locked solid, you will know that without running the engine first. This is highly probable since you describe a hanging exhaust valve. Something else to check since you are already in there would be if there is a rocker that is extremely sloppy. When the tension is off, all of them will wiggle a little bit, but if you can actually turn it side to side and touch the head with the pushrod, you may have a bent pushrod like the others mentioned. If you can actually get the pushrod out of the cup on the rocker, it more likely that the lifter is dead. I don't think that is the problem since you sound like you are hanging a valve open, not closed, but it is something to check. It is not a fun job, so you might as well check everything you can while you are in there. Turning the engine by hand is definitely an option to see the valves work, however everything happens so slowly that you might not recognize any abnormalities. Plus you probably won't be able to turn it yourself and watch everything at the same time. If you do turn it by hand, do yourself a favor and pull the plugs to release the compression. The way I have done it in the past is purchase one of those cheap remote start switches that you can hook to solenoid and watch from the engine compartment while you let the starter do the work. Just remember to pull the coil wire off so that it doesn't start on you. Sorry about being so wordy with these replies. I just wanted to be as specific as possible. Let me know how it goes. Thanks, hemlock

11-18-2003, 04:29 PM	#9
Big Bopper Registered Member Join Date: Jun 2000 Location: Sechelt, B.C., Canada Posts: 200	Hey Hemlock.... This may be a dumb question but...How will I know if it is "locked solid"? Do you mean the pushrod for the exhaust valve will be locked solid ..meaning it won't move or wiggle at all, no matter what the position of the motor is at ? thanks for your time and patience... Jolee __________________ 90' GT Drop-top, 88' 302,pulleys,full flowmasters (turndowns),Ported stock Intakes,twin flex-a-lites,Pro-5.0,3.55's,short belt,elctric water pump,timing bumped,taylor leads.(headers soon!)

11-19-2003, 07:55 PM	#10
hemlock Registered Member Join Date: Nov 2003 Posts: 3	Hi Big Bopper -- You'll know if that's the case. A lifter is made up of the lifter body, spring, seal, cup and circlip (locks everything in the lifter body. If the spring inside of it broke and twisted, it will lock up the seal from being able to pump up and down to push oil up the push rod. It can also be solid in the bottom position with a broken spring. Basically, it is the up and down that you are worried about with a locked lifter. You won't be able to push it down at all no matter what the position is. As a matter of fact, it is more than likely that the valve will be sitting open. Check with a straight edge if you can to see if it sitting low. hemlock

11-20-2003, 10:25 PM	#11
Big Bopper Registered Member Join Date: Jun 2000 Location: Sechelt, B.C., Canada Posts: 200	Hey Hemlock., I 've pulled one of the heads and i don't see anything wrong .... all the pushrods are sraight as fare as I can tell..took both sides of the pushrods out all seem to be real good ends smooth not blocked ect... All the valves on the head that I took (passenger side) off are in the closed position so ...I gueuss I'll take the other head off and check that one as well... I hope I haven't overlooked something real simple...like a bad plug or ...... bad plug lead....I don't Know,... I'm losing my mind .... I just assumed because of the tick that developed recently... Thanks for your advice Hemlock. Big Bopper __________________ 90' GT Drop-top, 88' 302,pulleys,full flowmasters (turndowns),Ported stock Intakes,twin flex-a-lites,Pro-5.0,3.55's,short belt,elctric water pump,timing bumped,taylor leads.(headers soon!)