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bowtie76 11-15-2010 01:27 PM

dead cylinder? Confused and about to lose my mind
i got a 1971 camaro with a stock SBC 350. I have a edlebrock intake with a 600cfm holley carb. I installed a Accel HEI dist a few months ago. car was running great. I was driving from NY to Virgina and the car started backfiring on the way down. When I pulled off the road I found that two of my spark plug wires burned up. I went ahead and replaced all the wires. tooki it back out on the road and it was still doing the same thing. I went ahead and pulled the plugs. Ifound a couple were fouled out in the same cylinders that the wires were burned. So I replaced all 8 plugs jsut to cover everything. I got back on teh road and it still did the same thing. Now confused I pulled the cap and rotor. All the points seemed like that had been burned up. i went ahead and cleaned them still didnt change anything. So I decided to get a new cap and rotor. After i installed it nothing changed. I talked to a fellow mechanic and he mentioned the coil. I didnt have any way to test the coil so having the extra money and no were near home I bought a new coil adn put it on. Still nothing.
finally after 8 weeks of being gone I was able to get home. i contacted accell and talked to them. the guy said it sounded like the control module was bad. I couldnt find the receipt he wanted so i took the distributor back to were I bought it and they warrantied it out. i dropped the new one in and still havent had any luck. Now being beyond mad I took it into a shop. They couldnt look into it for long. he did a couple quick checks on it and found that the #6 Cyl was 200 deg cooler then the other 7. He pulled the plug adn it was getting spark but it still looked brand new. he mentioned a possible sucked in intake gasket. I did bring it to work and replaced the valve cover gaskets and turned it over by hand. Saw all the valves moving. All though I did find the intake valve on the #4 cylinder was loose. you caould pick it up by hand and turn it around. I tightned it back down. But I dont know if I should pull the heads and intake off and replace the gaskets. I know at some point someone is going to tell me I am retarded for putting all the money into it replacing everything when i could have spent the money to take it to a shop to diagnose the issue. but I am past that point and I am at a point were I am ready to drive it over a cliff and leave it be. This is my everyday driver at this point. Can anyone help me out?

lmsport 11-15-2010 02:13 PM

Sudden loss of valve adjustment is usually a sign of camshaft failure. But, check that none of the rocker arm studs are being pulled out on the affected valves, and that no valve springs are broken

SDLuck 11-15-2010 03:00 PM

Compression test

bigdog7373 11-15-2010 05:17 PM

Run a compression test and leak-down test. Make sure none of the rocker nuts are over tightened or it will hold the valve open. Turn the engine over a few times and make sure all the rockers move the same amount. Make sure all the plugs are sparking and at the right time. Let us know what you find. :thumbup:

bowtie76 11-17-2010 06:10 AM

ok, so I decided on my day off to tear it down some. didnt have time to go to indepth on it.
I went ahead and removed the intake manifold. Needless to say that the gasket was beyond tore up. But it went down hill from there. I didnt have a compression gauge to check the cylinders. But I had a buddy turn it over by hand. I did find that the #6 was not sealing at all. both valves were moving good. however when it go into the compression stroke I could see bubbles leaking from the intake valve and you can hear a hissing noise coming from it. I also noticed that the two valves had a different amount of travel when they closed. the intake valave didnt seem toclose enough like the exhaust valve did. Also when i removed the intake the exhaust port that connects the #4 and #3 exhaust valves was clogged. i had to chisel it out with a screwdriver. I cleaned everything up and also noticed that on passenger side head there were large gouges taken out in the head by the #2 and #4 Intake valves. I did check the plugs and the amount of spark and the color of them. They all spark the same and all but the #6 plug are a slight brown color. the #6 is still white. I am sure at this point I need to replace he heads. I am sure I could probably get away with just getting a valve job. but seeing the knicks in the head concerned me. I replaced all the intake gaskets. I also reset the timing. it was also off some. it runs better than it did but is still popping when it is under a load. if I am gentle with it she seems to do ok but the slightest hill I had to climb you can feel the loss in power and she starts popping. Is there anything I could possibly do with the valves to fix them without replacing the heads or am I at the point I am lucky it is still running?

lanier ledford 11-17-2010 07:01 AM

dead cylinder
Next post, please go to the bottom of the page an hit the SPELL CHECK I think you'll be surprised. thanks

bowtie76 11-17-2010 07:15 AM

LOL Hey I never said I was perfect. But I will spell check it next time. i think you need to do the same. You got a word wrong in yours too.

454C10 11-17-2010 07:52 AM

need to do a compression check.

sounds like the cam is flat and the heads need work.

a valve job on an old v8 is 125.00, can get a summit cam and lifters for 110.00, and a gaskets for 60.00. so 300 dollars should cover it (plus your labor).

bowtie76 11-17-2010 07:58 AM

I know I need to do a compression check. I know it is easy and fast just a matter of getting the time off to get it done. I was expecting about that much for the parts. I guess i am going to have to force work into giving me the time off to get the compression checked. i know it was done years ago. i had the intake and rear main gaskets replaced. He said he ran the compression and all were up to 120 psi but the #8 cyl was running 90. Now it seems it has moved into other cylinders like a disease HAHA. imagine that!! Thanks for the info

Overdriv 11-17-2010 11:48 AM

I would also check and reset the preload on the hydraulic lifters before I did anything else. Then a compression check, among other things.

bowtie76 11-17-2010 12:00 PM

Ok well at this point I wont lie. You just spoke spanish to me. LOL I uno dos tres and that is it. I got the basics and can take something apart and get it back together like it was new. IF I know what I am looking for and doing. As for what i have done to i. I have dealt with all that before. but i have never really messed with the rockers other than tightening the one up that was about to fall off.

Overdriv 11-17-2010 02:28 PM


Originally Posted by bowtie76
Ok well at this point I wont lie. You just spoke spanish to me. LOL I uno dos tres and that is it. I got the basics and can take something apart and get it back together like it was new. IF I know what I am looking for and doing. As for what i have done to i. I have dealt with all that before. but i have never really messed with the rockers other than tightening the one up that was about to fall off.

Try this link from our knowledge base

kc8oye 11-17-2010 09:47 PM

hrrm.. I dont' see a delete post button.

bowtie76 11-18-2010 05:50 AM

Thanks overdriv. i am going to try that this weekend. doesnt look tough at all. Most of everything I have learned so far has been hands on. So again thanks. I am hoping that helps some. Only because I dont want to start learning how to install a new cam yet haha. I was hoping to do that when I find another engine. i have always wanted to build one from the ground up to put in my camaro. It is looking like I might be doing that sooner than later.
but i do have anotehr question. I have read a few places about the popping also being linked to a lean condition or retarded timing. i know the timing isnt retarded. But as for running lean. Well that I am unsure of. I know it has plenty of fuel flow. Is there a way to find out if it is running too lean?

bowtie76 11-19-2010 01:35 PM

Ok so here is a question i was pondering today at work. I know I had been told a possible bad lobe on my cam could cause the issue I have with my car. however, when I had the intake off and watching the valves open and close. They all did just that. the intake fully opened and just don't seem to close. So that would rule out a bad cam right? second It was mentioned to adjust the valve and make sure they are zero backlash. I read up on it. looks simple. But the question I have at this point. If i never had a issue up until recently, wouldn't the rocker be loose when the valve is closed? Not holding it open. A nut doesn't tighten itself down on a spring loaded valve. I am going to buy a compression gauge tomorrow morning and test the compression. but I wanted to get someones opinion on it before I start messing with the valves. There is one I know for a fact came loose and that was on the #4 cylinder intake valve. i just tightened it down to stop the slapping it was doing. So that I will adjust properly. but can someone answer the other questions I have please.

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