Lost a cylinder
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Not using the distributor rotor....using the balancer marks and watching the valves of #1....see if they match-up.....I suspect they will not if indeed the timing has jumped.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Service Engine lite come on?
.......................been a long frustrating weekend..... It will not idle at all.....and driving it anywhere is doubtful as it is a manual trans and trying to keep it running and shifting is not easy.
Yes I have the CCC and the E4ME carb....which was all running really good until the timing jumped..
Nothing is going to get taken apart until I know more about what happened. That I have got to get my 95 oil pan gasket to seal.
Yes I have the CCC and the E4ME carb....which was all running really good until the timing jumped..
Nothing is going to get taken apart until I know more about what happened. That I have got to get my 95 oil pan gasket to seal.
The code is a series of long an short flashes of the Check Engine/Service Engine lite.
I found something in a Chiltons on the CCC diagnostics. PM me if you need me to send you more info - maybe i can scan and attach to an email.
Hope this helps,
cardo0
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Nope...no Check Engine Light....
Have not checked the balance yet...plan to do so today. I did watch the valves as I rotated then engine....looks like exhaust rocker is moving before TDC is indicated. Going to put a wood dowel rod in the #1 spark plug hole and then rotate engine....see if I can tell when at TDC. Crude but should be good enough for now.
Have all the spark plugs out and may do a compression check....but was not pleased with the numbers I got last summer. Still think there is something wrong...perhaps the moly rings never seated or ????
More to follow on this.
Have not checked the balance yet...plan to do so today. I did watch the valves as I rotated then engine....looks like exhaust rocker is moving before TDC is indicated. Going to put a wood dowel rod in the #1 spark plug hole and then rotate engine....see if I can tell when at TDC. Crude but should be good enough for now.
Have all the spark plugs out and may do a compression check....but was not pleased with the numbers I got last summer. Still think there is something wrong...perhaps the moly rings never seated or ????
More to follow on this.
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Checked balancer for slipping...its good. Used a wood dowel and piston came up and aligned with TCD mark.
Was putting distributor back in and did notice that the oil pump shaft sure wiggles around alot. Put distributor in and aligned just fine.
Put compression gauge on #7 cylinder....this is one of the three that did not seemed to be firing.....compression was 132...same as it was last summer. Then I blocked-open the carb...redid compression and got 135. Squirted some oil into the cylinder and got 135.
It appears that the distributor may have jumped somehow...it was tight...but timing seems to be okay.
I am going to put all back together and see if it runs normally or still has the problem.
Then there is the low compression....will probably pull the heads off later and get some decent alumimun heads....as soon as I find a spare $1000 sitting around.
I will update with whether the engine runs or not.
Was putting distributor back in and did notice that the oil pump shaft sure wiggles around alot. Put distributor in and aligned just fine.
Put compression gauge on #7 cylinder....this is one of the three that did not seemed to be firing.....compression was 132...same as it was last summer. Then I blocked-open the carb...redid compression and got 135. Squirted some oil into the cylinder and got 135.
It appears that the distributor may have jumped somehow...it was tight...but timing seems to be okay.
I am going to put all back together and see if it runs normally or still has the problem.
Then there is the low compression....will probably pull the heads off later and get some decent alumimun heads....as soon as I find a spare $1000 sitting around.
I will update with whether the engine runs or not.
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Well....got the engine to run...but not very well. Still have a timing issue....did not get a chance to put a timing light on it...will do that tomorrow.
But hearing a knock, like a hammer inside the block. So it is possible I have spun a rod bearing(s) after all.....do not know yet.
I will see where timing is at tomorrow and go from there.
But hearing a knock, like a hammer inside the block. So it is possible I have spun a rod bearing(s) after all.....do not know yet.
I will see where timing is at tomorrow and go from there.
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Engine runs better with computer disconnected; checked timing with computer connected at at idle it was showing about 30 BTDC...not steady...moving around.
Disconnected computer...about 12 BTDC.
Pulled one plug wire off at a time....no real difference in engine sound, although #3 off seemed to run a bit smoother...but only for a few seconds. Good spark on all.
Engine has a periodic "shudder" to it....from what I have yet to determine.
Any ideas as to where to go from here??
Disconnected computer...about 12 BTDC.
Pulled one plug wire off at a time....no real difference in engine sound, although #3 off seemed to run a bit smoother...but only for a few seconds. Good spark on all.
Engine has a periodic "shudder" to it....from what I have yet to determine.
Any ideas as to where to go from here??
Last edited by LannyL81; Apr 3, 2011 at 02:43 PM.
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Think I found the problem
Removed valve covers again to check rocker arms and pushrods.....found #4 exhaust quite loose....took rocker arm off and noticed the exhaust valve spring seemed to be sitting lower than the others. Got all the rockers arms loose and began comparing exhaust spring heights....finally measured #4.....yes it is indeed lower by 1/8".
Put air to the cylincer with both rocker arms off.....air just flowed out the exhaust port.
So what has happened?
Valve seat broken and keeping the valve from closing?
Piston ring broke and a piece of it is wedge in the exhaust port?
Valve spring appears to be okay...no pieces anyways.
I do not have a valve spring compressor....so I will probably take the head off and hope the piston/rod/cylinder is not damaged.
Put air to the cylincer with both rocker arms off.....air just flowed out the exhaust port.
So what has happened?
Valve seat broken and keeping the valve from closing?
Piston ring broke and a piece of it is wedge in the exhaust port?
Valve spring appears to be okay...no pieces anyways.
I do not have a valve spring compressor....so I will probably take the head off and hope the piston/rod/cylinder is not damaged.
Last edited by LannyL81; Apr 3, 2011 at 06:55 PM.
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Drifting
Joined: Jun 2010
Posts: 1,781
Likes: 15
From: Oxford Ohio
Yes they can, on rare occasions. A bad overheat can help that along some. Compare the number running around to the number that drop, the odds are they aren't. Depends on how well they were installed. Look at all the cars with aluminum heads and how often you hear of one dropping.
That can eat the crap out of a head.
That can eat the crap out of a head.
Instructor
Joined: Apr 2009
Posts: 213
Likes: 0
From: Tulsa Oklahoma Area
Just a thought do these heads happen to have brass inserts in the guides. If so one could have seized to a valve stem or just loosened over time and dropped alittle bit...... I have seen more than one do it before?......
Drifting
Joined: Jun 2010
Posts: 1,781
Likes: 15
From: Oxford Ohio
If a valve would sieze open it would either get knocked shut or poke a hole in the piston. If siezed closed it would or could take out a cam lobe. There isn't really a safe place for one to decide stay.
I think I'd pull the heads and SEE what's going on, if it's the top end or not. A guy could spend the summer looking and hoping it's a quick easy cheap fix.
Run the normal tests, compression, vacume after it's with in reason with respect to timing. No compression, start digging.
I think I'd pull the heads and SEE what's going on, if it's the top end or not. A guy could spend the summer looking and hoping it's a quick easy cheap fix.
Run the normal tests, compression, vacume after it's with in reason with respect to timing. No compression, start digging.
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Some answers:
Yes the heads have bronze wall valve guides, about 8-9K miles ago.
Very possible that the valve guide has dropped, keeping the valve from closing. I am sure the valve is not siezed as it was rocking when I first stated trying to figure-out what had happened.
Hopefully the exhaust valve did not hit the piston....but the block is zero-decked so.........I will find out this weekend when I pull the head off.
May be I should start a poll.....did it or did it not hit the piston....??
Yes the heads have bronze wall valve guides, about 8-9K miles ago.
Very possible that the valve guide has dropped, keeping the valve from closing. I am sure the valve is not siezed as it was rocking when I first stated trying to figure-out what had happened.
Hopefully the exhaust valve did not hit the piston....but the block is zero-decked so.........I will find out this weekend when I pull the head off.
May be I should start a poll.....did it or did it not hit the piston....??
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Pictures
Well...here are the pictures...
#4 Valve:
#4 Piston:
So...valve is bent....hit the piston...where to go from here?? Piston does not appear to be damaged....just really clean in the shape of the exhaust valve.
I really do not want to pull the engine (again). Does anyone think I can just clean off all the piston tops, put new heads and gaskets on and be good to go for 100k miles???
Do not know why the valve hit the piston...timing appears to be fine. Will pull the front cover off and be sure of course...but I would think if timing did jump then other valve would be bent.
Suggestions.......................
#4 Valve:
#4 Piston:
So...valve is bent....hit the piston...where to go from here?? Piston does not appear to be damaged....just really clean in the shape of the exhaust valve.
I really do not want to pull the engine (again). Does anyone think I can just clean off all the piston tops, put new heads and gaskets on and be good to go for 100k miles???
Do not know why the valve hit the piston...timing appears to be fine. Will pull the front cover off and be sure of course...but I would think if timing did jump then other valve would be bent.
Suggestions.......................
Melting Slicks
Joined: Apr 2002
Posts: 2,337
Likes: 14
From: Norfolk VA
If it were mine I would remove the piston/rod assembly and have the piston checked out. The engine does not need to be removed to remove the piston/rod assembly provided you can get the vehicle high enough off the ground to tap the piston/rod assembly out as you would with the engine out. As for the valve, it will have to be replaced, you may be able to find a machine shop to replace the valve and repair the seats on that cylinder. I'm sure some may say this is bad info but I would do it. If you choose to remove the engine you might as well rebuild it completely.
Last edited by Oldguard 7; Apr 9, 2011 at 08:28 PM.
Melting Slicks
Joined: Feb 2006
Posts: 3,428
Likes: 5
From: Japan
If it were mine I would remove the piston/rod assembly and have the piston checked out. The engine does not need to be removed to remove the piston/rod assembly provided you can get the vehicle high enough off the ground to tap the piston/rod assembly out as you would with the engine out. As for the valve, it will have to be replaced, you may be able to find a machine shop to replace the valve and repair the seats on that cylinder. I'm sure some may say this is bad info but I would do it. If you choose to remove the engine you might as well rebuild it completely.
There's no reason to tear the engine completely down at this point...you've obviously found the problem, and thankfully before (It would appear, anyway) any major damage has occurred. The most important thing at this point would be to get that piston+rod out of the hole without doing any harm to the crank, inspect the rod journal for any damage, and the piston/wrist pin for any cracking or other damage around the pin boss. Just judging by the pics it looks like that valve just tagged the piston lightly so I really doubt if any serious damage was done there. Make sure you put sleeves over the rod bolts so you don't ding the crank, fix whatever's wrong with the head, be careful putting it back together and you should be fine.
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Using my finger I cannot feel any raised metal on the piston....so hopefully the wrist pin is okay. It is a floating wrist pin.
My plan is to remove #4 piston and check the wrist pin and rod bearings. Working under the car and removing the piston is going to take two people...to make sure the rod bolts do not nick the crank journals.
Not going to happen until two weeks from now.
Still trying to figure-out why I had two other cylinders that did not seem to be firing the last time I ran the engine. Looking at the top of piston #6 has alot of carbon flakes on it. Will pull the other head off tomorrow. Engine was sure running rich.
I am not going to have the heads repaired. They are reworked GM 882s and I had low compression for some reason. And it was not the rings, so these heads are headed for the neighbor's pool.......
My plan is to remove #4 piston and check the wrist pin and rod bearings. Working under the car and removing the piston is going to take two people...to make sure the rod bolts do not nick the crank journals.
Not going to happen until two weeks from now.
Still trying to figure-out why I had two other cylinders that did not seem to be firing the last time I ran the engine. Looking at the top of piston #6 has alot of carbon flakes on it. Will pull the other head off tomorrow. Engine was sure running rich.
I am not going to have the heads repaired. They are reworked GM 882s and I had low compression for some reason. And it was not the rings, so these heads are headed for the neighbor's pool.......
Melting Slicks
Joined: Feb 2006
Posts: 3,428
Likes: 5
From: Japan
As long as you put some sleeves over the rod bolts (I've always used a short length of 5/16" fuel hose cuz I'm too cheap to buy the real ones; it works fine) you'll be able to remove and install the piston without nicking the crank and without any help...the biggest PITA will be doing it in the car and trying to keep any trash from getting into the engine. Otherwise you shouldn't have anything to worry about...
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
I still have the yellow plastic sleeves I used when I put the engine together so that is not any problem.
I am looking at the Edelbrock E-Street heads as replacements. The cam I have meets the "under 0.550 lift" and since I am still using the computer (CCC system) I really cannot go any larger.
However there was a note regarding the 2.02 valves requiring additional valve to piston clearance...but that is all it states.
Now my block has been zero-decked, and as shown in the pictures, flat-top 2 valve relief pistons.....anyone know more about the statement above??
I am looking at the Edelbrock E-Street heads as replacements. The cam I have meets the "under 0.550 lift" and since I am still using the computer (CCC system) I really cannot go any larger.
However there was a note regarding the 2.02 valves requiring additional valve to piston clearance...but that is all it states.
Now my block has been zero-decked, and as shown in the pictures, flat-top 2 valve relief pistons.....anyone know more about the statement above??
Melting Slicks
Joined: Apr 2002
Posts: 2,337
Likes: 14
From: Norfolk VA
It means the cleareance between the top of the piston and the valve when it is open. To measure this is to take a piece of clay and place it across the piston head and put the cylinder on the block and rotate the engine when the intake valve opens. Remove the cylinder head and measure the indentation in the clay left by the intake valve. That measurement is the valve to piston clearance. Since your block is zero decked, it should be fine. I would chuck that computer.
So can anyone surmise as to what caused this to happen ?