Luke, Congrats on all the progress and it sounds like you have a good plan going forward 
Blowing 3 Gees on my Six
- Thread starter Luke76
- Start date
Luke, Congrats on all the progress and it sounds like you have a good plan going forward 
Gene Fiore
Famous Member
In regards to the coolant leakage around the head...was that on the drivers side? These sixes are prone to having slight leaks in this area. Re-torqueing the head as previously suggested may stop most of not all of the leakage. It did for me as I was having a slight leak when I got my new motor together. I am using a Corteco head gasket. BTW, I always re-torque the head when the motor is stone cold.
Regarding the lastest metal shavings you found under the valve cover. I noticed that you are running OEM type ball and cup pushrods. I had an issue awhile back where I was running the same pushrods as you have with an aftermarket rocker assembly and there was a fitment issue with the cup of the pushrod and the ball on the rocker. The ball did not fit all the way down in the cup of the pushrod and the pushrod cup was galling the ball of the rocker and knocking metal shavings off. Might want to check that if you haven't already. This was resolved when Mike supplied me with a set of aftermarket pushrods that have a slightly larger cup. Good luck with everything!
Regarding the lastest metal shavings you found under the valve cover. I noticed that you are running OEM type ball and cup pushrods. I had an issue awhile back where I was running the same pushrods as you have with an aftermarket rocker assembly and there was a fitment issue with the cup of the pushrod and the ball on the rocker. The ball did not fit all the way down in the cup of the pushrod and the pushrod cup was galling the ball of the rocker and knocking metal shavings off. Might want to check that if you haven't already. This was resolved when Mike supplied me with a set of aftermarket pushrods that have a slightly larger cup. Good luck with everything!
I can't wait to see a video of it running, man it's been a long wait... I can hardly believe it's been almost 2 years and I've been here watching/waiting the whole time LOL! I need a life...
I really like your project, I wish you got some power figures for us crazy people but maybe when your done you can go get a dyno to dial in the carb better, if not for power then longevity of engine
I'm glad to hear your still at it getting it sorted, Hopefully those weekend cruise nights will come sooner than expected, remember to post picks of engine bay when all is done
I really like your project, I wish you got some power figures for us crazy people but maybe when your done you can go get a dyno to dial in the carb better, if not for power then longevity of engine
I'm glad to hear your still at it getting it sorted, Hopefully those weekend cruise nights will come sooner than expected, remember to post picks of engine bay when all is done
Your compression numbers were pretty good.
That does not indicate the block needs work.
Why do they want to rebuild it? To make your wallet a little slimmer?
The leak may be from a warped head. You can check it with a proper straight edge when it's off. Same with the block.
The rattle could be from any number of things. You need to pinpoint the location.
I thinking torque converter as someone else has mentioned. It might have something to do with the funny vibration as well.
But down in that area I also had problems with the bracket that holds the oil pump screen. It was broken and the screen was rattling around. Both my fox-bodied cars had the same problem.
Another problem I had was a failing harmonic balancer. It has two sections with a rubber insert between them that can separate.
That does not indicate the block needs work.
Why do they want to rebuild it? To make your wallet a little slimmer?
The leak may be from a warped head. You can check it with a proper straight edge when it's off. Same with the block.
The rattle could be from any number of things. You need to pinpoint the location.
I thinking torque converter as someone else has mentioned. It might have something to do with the funny vibration as well.
But down in that area I also had problems with the bracket that holds the oil pump screen. It was broken and the screen was rattling around. Both my fox-bodied cars had the same problem.
Another problem I had was a failing harmonic balancer. It has two sections with a rubber insert between them that can separate.
Thanks for your comments Jack, the torque converter especially sounds like something I should chase down.
There are several sounds I've talked about and I've taken care of or at least identified everything except for this clack which sounds like someone wailing on the valve cover with a wrench. I can barely get it to happen in park if I really rev the engine, and even then it is extremely faint. However it is very loud and certainly noticeable, almost frightening, at certain throttle settings while at speed (>=40mph). To the extent I can hear it at all with my head stuck in the engine bay in park, it sounds like it is coming from somewhere from deep within the rear of the engine, at or below cylinder #6. So that would in fact be in the general area of the torque converter.
I am going to do some more reading about the TC. In the meantime, are there any simple diagnostics that could rule it in or out? I'm guessing it only comes into play when the transmission is in gear and moving? This kind of fits with the fact that we really only hear it while driving, although as I say if I really gun it in park you can barely kind of hear it even then.
In my cursory flip through the Chilton and Haynes tonight it seems like I'd have to drop the tranny to check out the torque converter - is that about right?
In fairness of my mechanic, he actually didn't recommend an engine rebuild - when I brought it in I told him not to do anything that would rack up major labor charges. I mostly wanted to see if knowledgeable eyes could detect something obvious which I, as usual, would have overlooked or known nothing about. He didn't say the scratched cylinders were definitely the cause, just that in the amount of looking he did, that was the only thing he saw which might be problematic, and could potentially account for what we were hearing. He didn't even have the head off - he inspected the cylinders with a borescope. In the end we both remained somewhat stumped pending further searching. In my present situation I am limited to further searching that doesn't involve pulling the block, only he kind of thought pulling the engine might be the next logical step.
Gene: yes, the head leak was in fact on the driver's side, every time. It seems to have disappeared after my last re-torque.
I also do in fact have an exhaust leak between the 3&4 cylinders, I think this is due to the incomplete manner in which the port divider was welded in at the machine shop. But anyway I know about that one and it can be fixed.
Luke
There are several sounds I've talked about and I've taken care of or at least identified everything except for this clack which sounds like someone wailing on the valve cover with a wrench. I can barely get it to happen in park if I really rev the engine, and even then it is extremely faint. However it is very loud and certainly noticeable, almost frightening, at certain throttle settings while at speed (>=40mph). To the extent I can hear it at all with my head stuck in the engine bay in park, it sounds like it is coming from somewhere from deep within the rear of the engine, at or below cylinder #6. So that would in fact be in the general area of the torque converter.
I am going to do some more reading about the TC. In the meantime, are there any simple diagnostics that could rule it in or out? I'm guessing it only comes into play when the transmission is in gear and moving? This kind of fits with the fact that we really only hear it while driving, although as I say if I really gun it in park you can barely kind of hear it even then.
In my cursory flip through the Chilton and Haynes tonight it seems like I'd have to drop the tranny to check out the torque converter - is that about right?
In fairness of my mechanic, he actually didn't recommend an engine rebuild - when I brought it in I told him not to do anything that would rack up major labor charges. I mostly wanted to see if knowledgeable eyes could detect something obvious which I, as usual, would have overlooked or known nothing about. He didn't say the scratched cylinders were definitely the cause, just that in the amount of looking he did, that was the only thing he saw which might be problematic, and could potentially account for what we were hearing. He didn't even have the head off - he inspected the cylinders with a borescope. In the end we both remained somewhat stumped pending further searching. In my present situation I am limited to further searching that doesn't involve pulling the block, only he kind of thought pulling the engine might be the next logical step.
Gene: yes, the head leak was in fact on the driver's side, every time. It seems to have disappeared after my last re-torque.
I also do in fact have an exhaust leak between the 3&4 cylinders, I think this is due to the incomplete manner in which the port divider was welded in at the machine shop. But anyway I know about that one and it can be fixed.
Luke
Yes you can do a Converter Stall Test Engine coolant should also be at normal operating temperature. A tachometer is but if after you done a few times you can start to feel it when there is trouble. Block chocks the rear wheels and set the parking and your foot on the brakes. Put the car in drive; stomp down on the accelerator pedal fully to read max engine rpm. Don’t hold the throttle wide open any longer than is necessary to get rpm reading, about 5 seconds is max. If you need to do more than one stall test run engine at about 1,000 rpm in neutral for couple minutes to cool the fluid. This test should isolate all the chassis noises you would have when driving so that you can hear if the converter is bad. The problem will be internal so taking out the converter to look at it usually doesn’t help much although if they are really bad you can shake them and hear some rattling when they are very loose inside. The cure is to get a rebuilt or new converter than
Good luck Luke
Yes it's a way to try and pin point if the sound is coming from inside the converter, but it will also show if the converter is operating correctly. I.e. stalling at correct RPM range roughly about 1200 to 1400. There are a few parts inside that can wear. See below pictures of converter cut away. First is a stock TC being cut open second is the stock TC open and the last is a TCI street performance TC so you can see the differences.
http://imageshack.us/g/15/c4splittingopenastockco.jpg/
http://imageshack.us/g/15/c4splittingopenastockco.jpg/
Ok, I've been reading about the torque converter and I see what you mean now about checking the stall RPM vs listed specs. Here is a very good article from AutoShop 101 about how the TC works (for other newbies that may stumble across this thread):
Torque Converter Article
I'll do the test and see what I get...
Torque Converter Article
I'll do the test and see what I get...
good deal I did the stall test today and over three tries the RPM averaged about 1900. I actually couldn't find the listed specs for the C4 in my searching, and they weren't in the shop manual either (it just says to refer to the Specifications Book, whatever that is). But from other discussions on the web 1900 seems pretty reasonable or maybe just a tad high. Does this sound ok to you guys?
I shot a brief video clip (below). You can see in the video that my car has a bad hesitation on start, the carb definitely needs some adjusting. It's bad enough that it killed the engine on one try. (Yes I allowed the TC to cool off between tests.)
The Clicking Sound was not particularly noticeable during these tests but that did not surprise me, it's really only audible when driving at higher speeds. However, if you turn the volume up on Test #3 at the end of the clip you will hear it when the engine is being revved.
In a few minutes I will post a second video where you can hear the Clicking Sound while driving.
Luke
Torque Converter Stall Test video: http://vimeo.com/34763250
I shot a brief video clip (below). You can see in the video that my car has a bad hesitation on start, the carb definitely needs some adjusting. It's bad enough that it killed the engine on one try. (Yes I allowed the TC to cool off between tests.)
The Clicking Sound was not particularly noticeable during these tests but that did not surprise me, it's really only audible when driving at higher speeds. However, if you turn the volume up on Test #3 at the end of the clip you will hear it when the engine is being revved.
In a few minutes I will post a second video where you can hear the Clicking Sound while driving.
Luke
Torque Converter Stall Test video: http://vimeo.com/34763250
Here is the video of me driving around in which you can hear the clicking sound I have been talking about. It is much more distinct in real life than in the video clip.
Video: http://vimeo.com/34764439
Video: http://vimeo.com/34764439
Yeah no sound from the converter in fact I don't know if I herd much over the exhaust leak. In the first video I think heard a little ticking that I would say was up top like valve train noise. My hearing is not the best sometimes though.
Yes Bubba, that noise that sounds like valvetrain up top is the one I am talking about. You're right, it's hard to hear over the exhaust, at least on the video.
You're right that it sounds like valvetrain. That is the first thing I thought and the first thing my mechanic thought. However the valvetrain is easy to access and observe and if you stick your ear right on you can tell it is actually coming from somewhere deeper in the engine. The rockers and valves themselves are working very smoothly and without noise.
This leads me to believe that scuffed cylinders might not be a bad guess overall... Otherwise I suppose it could be piston rod or something, though I don't know what that sounds like and I've heard those sorts of problems kind of get bad quick so you'd know it.
Luke
You're right that it sounds like valvetrain. That is the first thing I thought and the first thing my mechanic thought. However the valvetrain is easy to access and observe and if you stick your ear right on you can tell it is actually coming from somewhere deeper in the engine. The rockers and valves themselves are working very smoothly and without noise.
This leads me to believe that scuffed cylinders might not be a bad guess overall... Otherwise I suppose it could be piston rod or something, though I don't know what that sounds like and I've heard those sorts of problems kind of get bad quick so you'd know it.
Luke
Absent having a stethoscope, you can help track down the source of certain noises by putting a long handled screwdriver against the suspected source of the sound (e.g., on the valvecover) and putting the other end of the long handled screwdriver against your ear. This works well for things like ticking sounds, water pump bearing failures, etc./, as it helps transfer the vibration/sound.
Yes, we have done the screwdriver trick. The challenge in this instance is that you can hardly get the sound to occur at all when the car is parked, and I don't fancy driving at highway speeds with my head in the engine bay and a screwdriver to my ear.
However, to the extent I have been able to do this test at all the sound is clearly not coming from the valve cover area. It seems to be coming from below the head in the area of the #6 cylinder (ie, near the firewall).
Luke
However, to the extent I have been able to do this test at all the sound is clearly not coming from the valve cover area. It seems to be coming from below the head in the area of the #6 cylinder (ie, near the firewall).
Luke
I don't think it's a rod or piston sound those bottom end noise have a much deeper sound to them more like a thud. Another way to test for a rod, piston, or isolate a sound is to pull a plug wire one at a time while its running. You would need the special insolated pliers you would hear the sound change (be quieter) and then you know which cylinder the noise is coming from. As Soldmy66 said, with out a stethoscope, you can help track down the source of noises with a long handled screwdriver or a length of broomstick I always carried them on my serviced truck for that purpose. Couple other things to check is a fuel pump and bottom of oil (dented in) they both can sometimes make a hammering noise too. Did you happen to check the inside of the valve cover for signs of a rocker rubbing? How hard is it to get the exhaust sealed up that would help? Yeah that’s quite the problem to find an intermittent sound when you’re driving ithmm, could it be carb being too lean??
http://vimeo.com/34764439
"maintaining speed = sound"
"no pedal coasting = no sound"
"acceleration = no sound"
reason is because when your accelerating you use the power valve which feeds more gas, and coasting you retard the timing from the distrubutor canister. what would really help now is a vacuum gauge, and make note of where the vacuum is while it makes the sound @ acceleration/coasting/maintaining, or the the range of vacuum where it starts and ends. it's even possible to go further and check the A/F while you drive. another check could be the vacuum canister, see if it's breached...
Also try to make note of what speed/gear you are in with the vacuum gauge. hopefully it's just as simple as a few jet sizes. (we already know that cyl's 1 and 6 are the most lean, I think 6 is the worst cause it gets the least amount of cool water to help fight lean-ness)
http://vimeo.com/34764439
"maintaining speed = sound"
"no pedal coasting = no sound"
"acceleration = no sound"
reason is because when your accelerating you use the power valve which feeds more gas, and coasting you retard the timing from the distrubutor canister. what would really help now is a vacuum gauge, and make note of where the vacuum is while it makes the sound @ acceleration/coasting/maintaining, or the the range of vacuum where it starts and ends. it's even possible to go further and check the A/F while you drive. another check could be the vacuum canister, see if it's breached...
Also try to make note of what speed/gear you are in with the vacuum gauge. hopefully it's just as simple as a few jet sizes.
(we already know that cyl's 1 and 6 are the most lean, I think 6 is the worst cause it gets the least amount of cool water to help fight lean-ness)