[Z06] smoke out the rear exhaust
#41
If the valve head is fully detached from the valve then there should be lease pressure to the valve making the "wiggle test" even more pronounced. I know from experience. You might get lucky and be able to resleeve the cylinder. In my case I had water in the oil because the sleeve was compromised. My block didn't "window" but under closer inspection there was a hairline crack in the block around the cylinder and we determined that it was not going to be reused. You will need to take the head off to fully inspect. I took mine off in a couple hours and it wasn't a big deal. You just want to keep some sandwich baggies to put bolts in and a Sharpie felt marker to document. It may be a while before you can get it into a shop and you don't want to loose anything.
To get the best answer right a way is to dump your oil and look for coolant, it will be obvious. Save the head removal for later, you already know you have problems.
Good luck
To get the best answer right a way is to dump your oil and look for coolant, it will be obvious. Save the head removal for later, you already know you have problems.
Good luck
There is another case in here where there was a crack in the bore and a Darton Sleeve was used if I recall correctly, but I can't find that one just yet. I believe it was one that tjwong wrote about.
I also agree with draining the oil right away and having a look at it. Easy enough to do.
I remember your case SmokinZ.
On the dyno, got a lot of smoke when you let off it, and a couple weeks later it dropped an exhaust valve.
I also remember that it didn't window your block.
#43
The more of this stuff I read the more convinced I become that it is nothing to do with strength/hardness of the valve because I firmly believe the valves are momentarily sticking in the worn guide and being whacked by the piston and that would break any valve.
Therefore as far as I can see the only thing to ascertain is why the guides are wearing and was it a manufacturing problem. Seems hard to believe over such a long time frame. But once that is determined and if it can be remedied, I would expect the standard sodium valves are adequate for normal usage just as they are on an enormous number of other high performance vehicles coming from manufacturers worldwide - including even the LS9.
Of course changing the valves and guides may possibly be a good long term remedy but only time will tell if wear again becomes an issue. At present it is far too early to shout that the problem is solved even though it may look promising. The question then would be why the LS7 and not the LS9 with hardly a murmur on the ZR1 forum re engine probs.
It certainly is a serious issue judging by the number of problems arising here. And likely to get far bigger too.
I just hope the debate can return to the issue and move on from the bitching and point scoring. Everybody has an opinion and at present nobody is necessarily right or wrong. We need more data over time on rebuilt heads to be certain of anything. And it now takes too long to filter thru all the ******** and bickering for me.
Therefore as far as I can see the only thing to ascertain is why the guides are wearing and was it a manufacturing problem. Seems hard to believe over such a long time frame. But once that is determined and if it can be remedied, I would expect the standard sodium valves are adequate for normal usage just as they are on an enormous number of other high performance vehicles coming from manufacturers worldwide - including even the LS9.
Of course changing the valves and guides may possibly be a good long term remedy but only time will tell if wear again becomes an issue. At present it is far too early to shout that the problem is solved even though it may look promising. The question then would be why the LS7 and not the LS9 with hardly a murmur on the ZR1 forum re engine probs.
It certainly is a serious issue judging by the number of problems arising here. And likely to get far bigger too.
I just hope the debate can return to the issue and move on from the bitching and point scoring. Everybody has an opinion and at present nobody is necessarily right or wrong. We need more data over time on rebuilt heads to be certain of anything. And it now takes too long to filter thru all the ******** and bickering for me.
#44
Pro
From what I've read here, a dropped valve is often not obvious from that side of the head.
As to the oil drop, if it's got coolant in it there is no need to pull the head; the entire engine will need to come out. So... easier to drop the oil and see if pulling the head is worthwhile at this stage.
.
As to the oil drop, if it's got coolant in it there is no need to pull the head; the entire engine will need to come out. So... easier to drop the oil and see if pulling the head is worthwhile at this stage.
.
#45
The more of this stuff I read the more convinced I become that it is nothing to do with strength/hardness of the valve because I firmly believe the valves are momentarily sticking in the worn guide and being whacked by the piston and that would break any valve.
Therefore as far as I can see the only thing to ascertain is why the guides are wearing and was it a manufacturing problem. Seems hard to believe over such a long time frame. But once that is determined and if it can be remedied, I would expect the standard sodium valves are adequate for normal usage just as they are on an enormous number of other high performance vehicles coming from manufacturers worldwide - including even the LS9.
Of course changing the valves and guides may possibly be a good long term remedy but only time will tell if wear again becomes an issue. At present it is far too early to shout that the problem is solved even though it may look promising. The question then would be why the LS7 and not the LS9 with hardly a murmur on the ZR1 forum re engine probs.
It certainly is a serious issue judging by the number of problems arising here. And likely to get far bigger too.
I just hope the debate can return to the issue and move on from the bitching and point scoring. Everybody has an opinion and at present nobody is necessarily right or wrong. We need more data over time on rebuilt heads to be certain of anything. And it now takes too long to filter thru all the ******** and bickering for me.
Therefore as far as I can see the only thing to ascertain is why the guides are wearing and was it a manufacturing problem. Seems hard to believe over such a long time frame. But once that is determined and if it can be remedied, I would expect the standard sodium valves are adequate for normal usage just as they are on an enormous number of other high performance vehicles coming from manufacturers worldwide - including even the LS9.
Of course changing the valves and guides may possibly be a good long term remedy but only time will tell if wear again becomes an issue. At present it is far too early to shout that the problem is solved even though it may look promising. The question then would be why the LS7 and not the LS9 with hardly a murmur on the ZR1 forum re engine probs.
It certainly is a serious issue judging by the number of problems arising here. And likely to get far bigger too.
I just hope the debate can return to the issue and move on from the bitching and point scoring. Everybody has an opinion and at present nobody is necessarily right or wrong. We need more data over time on rebuilt heads to be certain of anything. And it now takes too long to filter thru all the ******** and bickering for me.
Any suggestions in there for helping this guy in the immediate evaluation and management of his current issues?
#46
Burning Brakes
Sorry Op but when you have that kind of contact it's a bad sign that your motor is now a boat anchor. Best thing to do is determine what you can afford(if any at this time) to try and get rolling again. Usually folks are making payments on the car when this happens and it's tuff.
I would start thinking about tearing the motor apart and go from there. You may be lucky and the block could be ok.
I would start thinking about tearing the motor apart and go from there. You may be lucky and the block could be ok.
#47
Assuming you do need a new block, you might want to call around to the big name performance shops to see if they know of any getting ready to hit the market.
When people upgrade to 6 bolt and get new sleeved blocks they sometimes have running LS7s to sell in complete form. I understood from one shop that 10k-11k is going rate.
A huge price but far below 15-18k
Still, I'd go through GM and work my way up the appeal ladder to see if you can't get some help (even if a partial amount) - even if not in warranty.
When people upgrade to 6 bolt and get new sleeved blocks they sometimes have running LS7s to sell in complete form. I understood from one shop that 10k-11k is going rate.
A huge price but far below 15-18k
Still, I'd go through GM and work my way up the appeal ladder to see if you can't get some help (even if a partial amount) - even if not in warranty.
#48
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No water came out of the oil. Here is what the oil looks like. This is what came out first and it was the same color until it stopped. No metal came out. I had a strainer under the oil.
#49
A ray of hope
Time to pull the head. Or borescope that cyl. Or pull those two rockers. Sing out of you need shop recommendations.
.
Time to pull the head. Or borescope that cyl. Or pull those two rockers. Sing out of you need shop recommendations.
.
Last edited by Mark2009; 05-06-2013 at 08:36 AM.
#51
Not looking as bleak as it was, but may as well go ahead and pull the head.
It's going to have to come off anyway.
Something did that to that spark plug. And the rest is somewhere.
It's going to have to come off anyway.
Something did that to that spark plug. And the rest is somewhere.
#53
Pro
[QUOTE=Mark200X;1583825824]A ray of hope
Time to pull the head. Or borescope that cyl. Or pull those two rockers. Sing out of you need shop recommendations.
Pull the rocker arms. Notice at the height of the valve stems. Pull on the stems or tap the stems with a rubber hammer or dead blow and see if they return to seat or spring upward. Do you have a borescope? Once again putting 80 psi of air will also verify if the cylinder has an effective seal. If not sealing (Leak down rate), you'll hear air escaping and be able to identify where it's going. Out the throttle body, out the exhaust, or internal to the crankcase. Then proceed to remove the head. Need to find the rest of that plug and do a visual inspection. If you tap the valves, remove the lash cap first, don't get carried away. Just want to lightly unseat the valve if it is still there. Sure don't want to put it into a piston that may be on Top Dead Center.
Time to pull the head. Or borescope that cyl. Or pull those two rockers. Sing out of you need shop recommendations.
Pull the rocker arms. Notice at the height of the valve stems. Pull on the stems or tap the stems with a rubber hammer or dead blow and see if they return to seat or spring upward. Do you have a borescope? Once again putting 80 psi of air will also verify if the cylinder has an effective seal. If not sealing (Leak down rate), you'll hear air escaping and be able to identify where it's going. Out the throttle body, out the exhaust, or internal to the crankcase. Then proceed to remove the head. Need to find the rest of that plug and do a visual inspection. If you tap the valves, remove the lash cap first, don't get carried away. Just want to lightly unseat the valve if it is still there. Sure don't want to put it into a piston that may be on Top Dead Center.
Last edited by JWingo; 05-06-2013 at 10:16 AM.
#54
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Jwingo, I like all of the tips. However, I know the basics of working on a car. Messing with the head is out of my area. Never played with rockers, springs, and valves. Taking the whole head off may be easier for me to do. I would like to see the write up on removing the head. I will go to the auto parts store for a borescope. What am I looking for? I don't have a shop of tools. I can do the basics.
#55
Pro
Jwingo, I like all of the tips. However, I know the basics of working on a car. Messing with the head is out of my area. Never played with rockers, springs, and valves. Taking the whole head off may be easier for me to do. I would like to see the write up on removing the head. I will go to the auto parts store for a borescope. What am I looking for? I don't have a shop of tools. I can do the basics.
#56
Pro
Too bad you are not local to me. I would be willing to lend a hand.
Last edited by Svre46; 05-06-2013 at 12:48 PM.
#57
Come on guys why waste more money on a borescope when without doubt the heads have to be removed anyhow.
Whip the head off and all will be clear to see. No point in stuffing around with this sort of damage because by the look of that plug it won't be a pretty sight.
Whip the head off and all will be clear to see. No point in stuffing around with this sort of damage because by the look of that plug it won't be a pretty sight.
#58
Any better pictures of that oil.? That is still some nasty looking oil IMO. Could be the way the picture was taken. Glad to hear no metal was found which could mean you are potentially in a better spot then others. Grab the borescope and scope that cylinder.
Too bad you are not local to me. I would be willing to lend a hand.
Too bad you are not local to me. I would be willing to lend a hand.
I was looking at that oil in the sunlight and on my phone when I posted up earlier.
At home on my desktop, that oil is as you say "nasty looking".
It's not "chocolate milk" looking which is what you can get when diluted coolant and oil mix. But it's not something I'd want to see when I drained the oil from my own car either.
#59
So a look-see thru the spark plug hole (or twigging the spring) could confirm a missing valve head. And if it is, if it were me I'd certainly approach GM about a good faith warranty... you never know. In which case you'd want to let them pull the head.
In the U.S. the major chain auto parts stores will 'lend' major tools if they have them (actually you buy it, and if you return it in good condition they give you a refund). Usually pullers and stuff like that.
#60
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Hey guys, I will get back on it Wed. I can't move the springs or rockers. Like one of the members said the head will have to come off. not as easy as the rocker cover.