Timing belt brain fart
08-06-2010, 11:48 PM
#61
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at this point pulling the cams is a pain the butt to do.
It would be best to turn the crank to 45 and then you can turn the cams any way you want. Just turn slowly so you dont cause additional damage when the piston hits the valve by turning either of the cams the resistance will either increase or decrease and the most that the crank would have to be turned is 180 degrees or less (half a turn or less)
That said since the OP may not be a shop mechanic or even a backyard mechanic why add additional steps ??
Taking the cams can cause other issues that at this point dont need to be found.
Though its likely that the valves did get bent .
It is worth a chance that if the steps i posted are followed he can find out if the engine will run without any more disassembly
It would be best to turn the crank to 45 and then you can turn the cams any way you want. Just turn slowly so you dont cause additional damage when the piston hits the valve by turning either of the cams the resistance will either increase or decrease and the most that the crank would have to be turned is 180 degrees or less (half a turn or less)
That said since the OP may not be a shop mechanic or even a backyard mechanic why add additional steps ??
Taking the cams can cause other issues that at this point dont need to be found.
Though its likely that the valves did get bent .
It is worth a chance that if the steps i posted are followed he can find out if the engine will run without any more disassembly
08-07-2010, 12:12 AM
#62
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Best to heed....
Comment anyway you want. Enjoy.
This engine might not have a thing wrong with it. No sense messing it up. Take a breath.
We all know how to fix bent valves if it come to that.
Guys with this Kohler engine advice need to lay off.
With some careful movements, like a safecracker would employ, the cams and crankshaft can likely be re-indexed into time.
THEN its possible to assess.
And with some luck, a fair amount of luck actually, the engine might be saved without disassembly. That's what we are talking about.
Think Apollo 13. Some of the guys on this board work at NASA, really. Let them work.
This engine might not have a thing wrong with it. No sense messing it up. Take a breath.
We all know how to fix bent valves if it come to that.
Guys with this Kohler engine advice need to lay off.
With some careful movements, like a safecracker would employ, the cams and crankshaft can likely be re-indexed into time.
THEN its possible to assess.
And with some luck, a fair amount of luck actually, the engine might be saved without disassembly. That's what we are talking about.
Think Apollo 13. Some of the guys on this board work at NASA, really. Let them work.
Good Advice.
08-07-2010, 12:27 AM
#63
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OK, let's back up a little.
We know you didn't pay attention to where the cam gears were when you installed the belt.
In your more recent statement you seem to be doing things OK now - you have the crank at 45 degrees, for example.
WHEN YOU WENT TO REMOVE THE BELT AFTER YOU REALIZED YOUR MISTAKE DID YOU HAPPEN TO NOTICE WHERE THE CAM GEARS WERE WITH THE CRANK AT 45 DEGREES?
If the timing marks were anywhere close to 3 teeth counterclockwise, you should be OK. Also, note that they can be 180 degrees off from that and be fine, as the cams rotate once for every 2 revolutions of the crank.
You wrote above that you have the crank at 45 degrees. You got a little confused by all the other 45 degree incremental positions others were suggesting. You don't need to worry about that now.
It would be good if you knew the answer to my question in caps, but regardless I would procede to get the belt back on correctly and see how the engine rotates with the plugs out, etc.
We know you didn't pay attention to where the cam gears were when you installed the belt.
In your more recent statement you seem to be doing things OK now - you have the crank at 45 degrees, for example.
WHEN YOU WENT TO REMOVE THE BELT AFTER YOU REALIZED YOUR MISTAKE DID YOU HAPPEN TO NOTICE WHERE THE CAM GEARS WERE WITH THE CRANK AT 45 DEGREES?
If the timing marks were anywhere close to 3 teeth counterclockwise, you should be OK. Also, note that they can be 180 degrees off from that and be fine, as the cams rotate once for every 2 revolutions of the crank.
You wrote above that you have the crank at 45 degrees. You got a little confused by all the other 45 degree incremental positions others were suggesting. You don't need to worry about that now.
It would be good if you knew the answer to my question in caps, but regardless I would procede to get the belt back on correctly and see how the engine rotates with the plugs out, etc.
08-07-2010, 02:28 AM
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OK. let's go your way. Did anyone suggesting the safe crack method also suggest three people with wrenches on hand. One with a 27mm socket to turn the crank and two others with 30mm wrenches to handle the cams using the inner washer to turn them? The cams are going to want to snap forward or backward inviting more damage. If there are no added violent crashes, then the miracle realignment might be acheived. After all, if it's not a potential danger, why do we change out interference 928 engine TBs at 45 degrees?
08-07-2010, 02:39 AM
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I must still be suffering from "pump head" from my heart surgery. I'm not following a lot of the suggestions. He's just said he has the crank at the 45 degree mark. And he's written that at some point the cams were only off a tooth. All this stuff about 3 wrenches and cams crashing and various 45 degree increments are great ideas but do not apply anymore. He should be in the final stages of getting the belt on correctly and then finding out if the motor will turn. He tried to start the motor after the original belt job and the motor turned freely but did not fire. Either the damage is already done or he just forgot to reattach the coil wires. No more damage can be done by getting the belt on and then seeing where he stands.
08-07-2010, 02:45 AM
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I must still be suffering from "pump head" from my heart surgery. I'm not following a lot of the suggestions. He's just said he has the crank at the 45 degree mark. And he's written that at some point the cams were only off a tooth. All this stuff about 3 wrenches and cams crashing and various 45 degree increments does not apply anymore. He should be in the final stages of getting the belt on correctly and then finding out if the motor will turn.
Edit: This what I read:
"Ok to reiterate where I am and what I did.
1) I took the belt off while repairing a leaking oil pump and did not pay attention at all where any marks where ( AT ALL)
2) Started turning the car over after assembly but it would not start. Did not hear any terrible sounds it just wouldn’t start or fire.
3) Took it all apart again lined it up to the 45deg. mark on the crank but I am not sure if it is at 45 / 135 / 225 or 315 At this time but the motor turned by hand, but forgot to set it to #1 cylinder redid the belt. The belt was off like a tooth on each cam counter clockwise.
***** ( While having the belt off both cam gears sprung back about 1 ½ inches the passenger side made a not so nice noise, The driver side didn’t seem to sound as bad. It happen to the driver side first so I didn’t think much of it.
4) Put it back together and tried to turn it by hand before I started it and I hit a hard spot and I stopped. That’s where I am now.
So I am at the 45 deg. But at this time I do not know what which rotation 45 / 135 / 225 or 315
I don’t know if this sheds any light on this or makes if worse, I guess we’ll see.
I hope to get back to it this weekend. I think I have enough info to be dangerous "
08-07-2010, 02:50 AM
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Now then. Eventually he's going to need it at the real 45 degree mark and set the cams three teeth off. You suggesting he do this without three people and three wrenches? Can he just rotate all together using the TB after setting at any 45 degree mark. I think not. But I'll let the NASA guys give us the final word.
08-07-2010, 02:53 AM
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Last I read he thought he had it at some degree of 45 but not sure which one and was encountering resistance. Correct me if I'm wrong.
Edit: This what I read:
"Ok to reiterate where I am and what I did.
1) I took the belt off while repairing a leaking oil pump and did not pay attention at all where any marks where ( AT ALL)
2) Started turning the car over after assembly but it would not start. Did not hear any terrible sounds it just wouldn’t start or fire.
3) Took it all apart again lined it up to the 45deg. mark on the crank but I am not sure if it is at 45 / 135 / 225 or 315 At this time but the motor turned by hand, but forgot to set it to #1 cylinder redid the belt. The belt was off like a tooth on each cam counter clockwise.
***** ( While having the belt off both cam gears sprung back about 1 ½ inches the passenger side made a not so nice noise, The driver side didn’t seem to sound as bad. It happen to the driver side first so I didn’t think much of it.
4) Put it back together and tried to turn it by hand before I started it and I hit a hard spot and I stopped. That’s where I am now.
So I am at the 45 deg. But at this time I do not know what which rotation 45 / 135 / 225 or 315
I don’t know if this sheds any light on this or makes if worse, I guess we’ll see.
I hope to get back to it this weekend. I think I have enough info to be dangerous "
Edit: This what I read:
"Ok to reiterate where I am and what I did.
1) I took the belt off while repairing a leaking oil pump and did not pay attention at all where any marks where ( AT ALL)
2) Started turning the car over after assembly but it would not start. Did not hear any terrible sounds it just wouldn’t start or fire.
3) Took it all apart again lined it up to the 45deg. mark on the crank but I am not sure if it is at 45 / 135 / 225 or 315 At this time but the motor turned by hand, but forgot to set it to #1 cylinder redid the belt. The belt was off like a tooth on each cam counter clockwise.
***** ( While having the belt off both cam gears sprung back about 1 ½ inches the passenger side made a not so nice noise, The driver side didn’t seem to sound as bad. It happen to the driver side first so I didn’t think much of it.
4) Put it back together and tried to turn it by hand before I started it and I hit a hard spot and I stopped. That’s where I am now.
So I am at the 45 deg. But at this time I do not know what which rotation 45 / 135 / 225 or 315
I don’t know if this sheds any light on this or makes if worse, I guess we’ll see.
I hope to get back to it this weekend. I think I have enough info to be dangerous "
08-07-2010, 03:02 AM
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The bold part is key. There's only ONE 45 degree mark. He's just confused by all the other degree suggestions. You guys have got him thinking that each time he rotates the crank to the 45 degree mark it changes to some multiple of 45. Now, I could be wrong too, but that's the way I read it.
But I still think it's FUBAR because he's still getting resistance.
Last edited by DuncanR50; 08-07-2010 at 03:22 AM.
08-07-2010, 03:22 AM
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BUT here's why I think he might be OK. He took the belt off and he put it back on. The crank HAD to be locked in order to remove the crank bolt so he could get the pulley and center cover off so he could remove the belt (and fix the oil pump, his primary intent). And it had to still be locked to reinstall the crank bolt after this work was done. So, at least we know the crank did not move. Plus, it just doesn't move on its own anyway. Also, the engine tends to stop at points where the cams are in the most stable position. So, if he locked the crank there instead of at 45 degrees BTDC, there's a decent chance the cams did not move when he removed the belt.
I don't know if the resistance he is feeling is valves hitting pistons or just the normal resistance to turning the crank against compression.
08-07-2010, 03:32 AM
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Yes, if he truly put the belt on at a random position, then it's highly likely the valves are FUBAR.
BUT here's why I think he might be OK. He took the belt off and he put it back on. There's a decent chance nothing moved in the interim. The crank HAD to be locked in order to remove the crank bolt so he could get the pulley and center cover off so he could remove the belt (and fix the oil pump, his primary intent). And it had to still be locked to reinstall the crank bolt after this work was done. So, at least we know the crank did not move. Also, the engine tends to stop at points where the cams are most stable. So, if he locked the crank there instead of at 45 degrees BTDC, there's a decent chance the cams did not move when he removed the belt.
I don't know if the resistance he is feeling is valves hitting pistons or just the normal resistance to turning the crank against compression.
BUT here's why I think he might be OK. He took the belt off and he put it back on. There's a decent chance nothing moved in the interim. The crank HAD to be locked in order to remove the crank bolt so he could get the pulley and center cover off so he could remove the belt (and fix the oil pump, his primary intent). And it had to still be locked to reinstall the crank bolt after this work was done. So, at least we know the crank did not move. Also, the engine tends to stop at points where the cams are most stable. So, if he locked the crank there instead of at 45 degrees BTDC, there's a decent chance the cams did not move when he removed the belt.
I don't know if the resistance he is feeling is valves hitting pistons or just the normal resistance to turning the crank against compression.
If he moved the tensioner to the full slack position and slid the belt off without any effort......yada...yada...yada. But we know the cams moved because he tried to start the car and it will not fire up because it's out of sync. Suppose one cam jumped to the next stable point and the other stayed. It's bad juju any way you look at it IMO. Hey, I'm not wishing anything bad on any 928 owner.
At this point I recommend DO NOTHING UNTIL YOU POST PICTURES!!!!
Does that sound reasonable?
08-07-2010, 04:09 AM
#73
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If he moved the tensioner to the full slack position and slid the belt off without any effort......yada...yada...yada. But we know the cams moved because he tried to start the car and it will not fire up because it's out of sync. Suppose one cam jumped to the next stable point and the other stayed. It's bad juju any way you look at it IMO. Hey, I'm not wishing anything bad on any 928 owner.
At this point I recommend DO NOTHING UNTIL YOU POST PICTURES!!!!
Does that sound reasonable?
At this point I recommend DO NOTHING UNTIL YOU POST PICTURES!!!!
Does that sound reasonable?
I was involved in an incident with an 87 where the water pump siezed and the belt welded itself to the pulley causing the crank gear to strip a dozen teeth off the belt (i.e., the crank kept turning, but the belt and cams didn't). It looked like a certain fatality. Real bad juju. We put in a fresh water pump and belt and the car started and ran perfectly.
08-07-2010, 04:34 AM
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We don't know what you say in the bold part. All we know is the car did not start. There were no horrible noises of valves hitting pistons. It just didn't start. The coil wires have to be removed to do this job. That's one of many other possible explanations. If he just took the belt off and didn't move anything and put it back on, then there shouldn't be a problem. All he has said is that the cams did not line up when he looked at them with the crank at 45 degrees. They could have just been 180 degrees off if he was at 45 BTDC on cylinder 6 instead of 1. This is not yadda, yadda, yadda. I've done more of these belt jobs than I can remember and have made almost every mistake you can make. I'm doing one right now and made a couple of new mistakes (Note: I must be more careful next time when I pull off the 14-pin connector). Anyway, I think he should just finish putting it back together properly (he appears to me to be close), try turning it over with the plugs out (although there will be a fair amount of resistance just from the valve springs). Heck, he might as well just try to start it. He can't do any more damage if he has the belt on right this time. If it doesn't run properly, then a leakdown will tell him which cylinders are damaged.
I was involved in an incident with an 87 where the water pump siezed and the belt welded itself to the pulley causing the crank gear to strip a dozen teeth off the belt (i.e., the crank kept turning, but the belt and cams didn't). It looked like a certain fatality. Real bad juju. We put in a fresh water pump and belt and the car started and ran perfectly.
I was involved in an incident with an 87 where the water pump siezed and the belt welded itself to the pulley causing the crank gear to strip a dozen teeth off the belt (i.e., the crank kept turning, but the belt and cams didn't). It looked like a certain fatality. Real bad juju. We put in a fresh water pump and belt and the car started and ran perfectly.
Sounds like the last time I had to do the WP/TB, but luckily I only had about a 1/4 of a cup of melted TB stuck to the WP drive wheel. The tension warning light and increase in coolant temp got me to pull over in time.
08-07-2010, 05:04 AM
#75
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Another guy here saved his engine the same way a couple weeks ago. Siezed pump, light came on, he shut it down quickly. And saved it like you did. Gotta respect the warning light design!