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General Information => General => Topic started by: wadem on January 09, 2013, 12:22:55 pm
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Hi again guys, so after my last advanced timing post and been so pleased with how my AAZ is running, I now have a new problem.
For the third time, thats right 3 times in a row, my timing is going out all by itself. I could tell the first time that it was not running as well as it had been since the advanced timing thread. Harder starting and different sound. So, pulled it all apart again and saw that it was out! At TDC on the crank the cam was just a smidge off as well as the pump had become more retarded. Set it all up again and it drove fine for another day or 2 then it happened again. Same routine, found it out again, fixed, and back together this morning. Running awesome again, but i'm thinking it won't last.
The car runs just fine going down the road, lots of power and no smoke, but again you could tell it was just a little out from the optimum setup that i locked it into. I dont think its out enough to blame it on a skipped belt cog. Its like something is coming loose just enough to upset the balance slightly. My cam sprocket is torqued to 33 foot lbs, the IP sprocket (adjustable) has the 3 bolts and they are very tight. I have read some info that this could be the nasty crank bolt issue! But mine has the newer multi point bolt in it and its so tight i cant budge it even with a 4 foot snipe.....what am i missing here?
My sequence to tighten and adjust has been, TDC on the flywheel, lock cam, loosen cam bolt, line up cam and lock it in, torque cam bolt, recheck that nothing has moved, adjust the IP to same setting as before, torque those up...thats it. The last 2 times I spun the crank over via the crank nut about 100 times and all was still lined up.
So wuz up!!!
Wade
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Hi again guys, so after my last advanced timing post and been so pleased with how my AAZ is running, I now have a new problem.
For the third time, thats right 3 times in a row, my timing is going out all by itself. I could tell the first time that it was not running as well as it had been since the advanced timing thread. Harder starting and different sound. So, pulled it all apart again and saw that it was out! At TDC on the crank the cam was just a smidge off as well as the pump had become more retarded. Set it all up again and it drove fine for another day or 2 then it happened again. Same routine, found it out again, fixed, and back together this morning. Running awesome again, but i'm thinking it won't last.
The car runs just fine going down the road, lots of power and no smoke, but again you could tell it was just a little out from the optimum setup that i locked it into. I dont think its out enough to blame it on a skipped belt cog. Its like something is coming loose just enough to upset the balance slightly. My cam sprocket is torqued to 33 foot lbs, the IP sprocket (adjustable) has the 3 bolts and they are very tight. I have read some info that this could be the nasty crank bolt issue! But mine has the newer multi point bolt in it and its so tight i cant budge it even with a 4 foot snipe.....what am i missing here?
My sequence to tighten and adjust has been, TDC on the flywheel, lock cam, loosen cam bolt, line up cam and lock it in, torque cam bolt, recheck that nothing has moved, adjust the IP to same setting as before, torque those up...thats it. The last 2 times I spun the crank over via the crank nut about 100 times and all was still lined up.
So wuz up!!!
Wade
i would bet that your crank sprocket keyway is just about dead..
does your crank pulley wobble at all?
the only way your timing can change on its own, is when the crank sprocket key, and crank keyway are worn out..
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Key shearing? Tensionor not tight or have the right washer under the nut?
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Key shearing? Tensionor not tight or have the right washer under the nut?
usually when they jump teeth, the valves get wrecked..
i doubt the belt is jumping time.. i imagine the keyway is trashed, and the timing is changing because the crank sprocket cant stay located in one spot..
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time for a tdi crank sprocket upgrade id say.
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So anyone know why VW switched to the keyway design, instead of keeping the old style taper fit?
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All the info i have read says that the last IDI's (1996)were not susceptible to the loosening crank bolt/sprocket! If the bolt s so tight that you cant budge it with a 4 foot snipe, how could the sprocket be loose?
Also, is there a work around or a home made tool that i can make/use to lock the crank while i attempt to remove the bolt? Or is it imperative that you use the proper VW locking tool?.......not really looking forward to this >:( >:(.
I guess it is my hobby car but I think i have had this thing ripped apart about 5 times in 1 week!
Any tips on how to do this job would be great......
Thanks guys
Wade
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Before you rip it apart, you might consider marking each sprocket and determining exactly what is moving/changing.
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PS: I'd use a scratch-awl to make fine marks.
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Impact guns get bolts out of spinny locations
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I thought the AAZ had a keyway cam sprocket also?
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So anyone know why VW switched to the keyway design, instead of keeping the old style taper fit?
they never had a tapered fit on the crank sprocket.. its always been a ghetto design since the water cooled inline 4 cylinder came out in the early 70s..
they changed from the original style, to the TDI D-shaped crank snout and friction fit sprocket just because of soo many crank nose failures..
and as for the cam, no diesels EVER came with a key in the keyway on the cam.. they are a taper fit, and never were intended to use a key to locate the pulley, like on a gasser..
and if your belt is tight, then the only thing that is changing your timing, is a slipping crank sprocket..
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sorry, I though I read that AAZs had a keyed cam sprocket. I also thought we were talking about the cam sprocket not the crank sprocket ::)
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sorry, I though I read that AAZs had a keyed cam sprocket. I also thought we were talking about the cam sprocket not the crank sprocket ::)
nope, no diesel ever had a key in the keyway on the cam..
CRANK sprocket.. the one on the bottom of the engine.. the one that the pulley bolts to..
start your engine, and look at your crank pulley as the engine is running.. does it have ANY run-out? does it wobble AT ALL? you should barely be able to tell that the crank pulley is spinning, because it runs soo true..
if your crank pulley has any wobble to it AT ALL, then i would remove the crank bolt, and inspect the crank nose, and the crank sprocket..
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Good info, thanks guys. I looked at the crank pully while running and it was almost perfect....almost. So i guess as you say it should come apart. I think that the only thing that could be doing this is the crank sprocket.......so stay tuned and i will forward the results.
So just to give me more thoughts so i dont sleep tonight, if the crank keyway is damaged or smashed up, is there an in car fix for this? I love my old Jetta, but i bought the car for 600 dollars 2 years agao and it has been a love of labour ever since. I have learned a ton about the IDI's, mostly from you guys. But i think before I rip a crank and engine out of her, i would probably just let it go. Kinda of too bad because it runs great, air con and cruise actually work, its a great hobby car!
Anyway, if i can get away with just replacing the crank sprocket and bolt, wonderful. If there is a in car repair for a worn crank nose, might consider that. Anything more invasive and its bye bye :'( :'(
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..... I think Andrew Libby has in car fixes for this issue. Libbydiesel is his name on here, shoot him a PM.
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..... I think Andrew Libby has in car fixes for this issue. Libbydiesel is his name on here, shoot him a PM.
broach the crank, and install a TDI crank sprocket..
Andrew has a tool fixture made up to do the work in the car...
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I don't think he rents it out unless it is in his area. It could be copied and I think the one guy was doing that, but never finished.
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What about somehow securing the sprocket to the crank by some other means. Spot welding, or using some kind of drill and pin method. Even generous amount of JB weld? could you fill in the keyway with JB weld or some other type of poor mans weld, and then file/grind it out to the correct tolerance to fit the key in the sprocket? Or would all this just be too soft and not durable enough.........I realize its caveman tactics, but am just wanting to keep it running for a little while longer without huge expense or time.
Again I haven't torn it down yet so don't really know what I will be faced with, but all the evidence points towards a wrecked crank keyway!
Wade
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I think some folks have pinned the sprocket. JB won't hold up.
(I would put some witness marks on the bolt, washer and sprocket to see what's moving... the sprocket likely is, but I like to validate.)
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Ya that's probably a good idea, I was sort of afraid to drive it as is because of the fear of God that some have thrown into me with regards to the sprocket or bolt failing completely. I have checked the bolt and its not loose, how much time do i have? Tough one. I can't see the key way in the sprocket letting go entirely. So as long as the bolt stays in I think the worst that can happen would be for it to just go out of time again.
Or maybe I'm just living in fantasy land?????
Wade
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I've seen the key sheer off completely. Yes, I have a broach/jig that lets me mod them in car. No, I don't rent it out. I'm in Flagstaff, AZ.
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What about somehow securing the sprocket to the crank by some other means. Spot welding, or using some kind of drill and pin method. Even generous amount of JB weld? could you fill in the keyway with JB weld or some other type of poor mans weld, and then file/grind it out to the correct tolerance to fit the key in the sprocket? Or would all this just be too soft and not durable enough.........I realize its caveman tactics, but am just wanting to keep it running for a little while longer without huge expense or time.
I'd expect about a week.
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745 I think you we're generous with a week! Man, 5 days ago I checked that nut and it was so tight I couldn't budge it, today it came of like it was stuck in peanut butter ;D ;D
It's a lot worse than I thought, here are the pics...........your thoughts gents?
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I'd call that a save.... a crank nose-job is better than a basket full of destroyed engine.
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745 I think you we're generous with a week! Man, 5 days ago I checked that nut and it was so tight I couldn't budge it, today it came of like it was stuck in peanut butter ;D ;D
It's a lot worse than I thought, here are the pics...........your thoughts gents?
I was talking about if you welded or glued it.
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I say you spray the nose of the crank with some lube, maybe PAM from the Kitchen, no not the cook either. Then you get a blob of clay from the kid down the street or the hobby store, which ever is closer. Then you put that on the back of the pulley and form it to the nose of the crank to get an impression. Carefully remove the pulley and use the clay impression as a model for some metal you bead up on the pulley with a welder. Does not have to be perfect just more secure than what you have going currently. Which is next to Nada but you now know that.
I can't see getting heat to the crank without damage to the seal so that is why I am going fab on the pulley route. You can't drill and pin this either as you don't have the engine out of the bay. That and the crank would likely walk a small bit right off anyway even if you did drill an access hole in the fender. Or drop the engine some off the engine mount on that side and the middle. Bet those pics were about all the room you had to slip a cell phone down there.
Amazing that you didn't blow this up already. But then you say you aren't driving it right?
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http://forums.vwvortex.com/showthread.php?1598023-Here-is-my-complete-Crank-Fix../page3&highlight=drill+crank+timing+gear
That is another fix, but tons of work too. I like the D sproket as if you would ever lose it in a rebuild or something you do not have to re make it. You just get another D sprocket.
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Thanks for the ideas! Orcoaster, i think i may give your suggestion a try. It seems to be the least amount of work and doable with the engine still in the car. I think that with a new bolt, and a built up sprocket it may last for awhile until I decide to either ditch the car or do a proper TDI crank fix.
Now that I know what the signs are, change in timing,engine sound, harmonic balancer wobble, I am hopeing that I can somehow visually mark the crank sprocket/bolt and check it and retorque every lets say 500 to 1000 kilometers. Possibly squeek another few klicks out of it.
Coaster, have you tried this technique or had success with it? I have a basic wire feed welder and I am a very BASIC welder, would this be adequate?
Just out of curiosity, if one were to choose the dowel/pin fix, how deep or how far can you or should you drill into the crank nose?
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I could weld and machine that crank nose to the D-shape in the car, but it would be a lot of work (and the car would have to be in Flagstaff in nicer weather - it was -13°F at 8:00a.m. this morning...).
You can pull the cam (and glow plugs or injectors for easy spinning) and use the starter to spin the crank. I made a jig to hold my dremel tool against the flat pulley end of the block. It works a treat for truing up the crank nose.
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I have used this technique to fabricate other things of this nature where you need a tab to go into a hole to align or keep it steady. I have not tried it in this manner. Just seemed similar work/fix and you were needing something quick and easy and somewhat durable. It is the durability that eludes me. I don't thing it gets a lot of pressure or force once the proper tab is in the hole.
You will actually end up with more supporting tab or button than stock with doing it this way. Maybe as much as 4 times the width of the original? Ok, 3 times. Think like a sculpture, bring out the artist in yourself. Make it function and perhaps it will be beautious as well.
Good luck. DAS
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Make it function and perhaps it will be beautimous as well.
In the words of Honey Boo-Boo herself.. lol err his self?
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Who the heck is Honey Boo Boo? I am such a social basket case. Maybe if I didn't spend all the time I have on this forum I would be in the know. TV? not since about 1974 guys. Couldn't take it no more and I bet it hasn't improved much since.
I am guessing Reality Show that really isn't real at all.
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Hey guys, have decided to pin the crank as I believe that will probably be best for my situation. I managed to drill the sprocket today and that went well, the crank was a little trickier but I managed to get it done. How deep should i drill into the crank for the pins? Also what is the best kind of pin or dowel to use? Some of the threads suggest using drill bits while others say not a good idea as they are strong but too brittle, I went with a 5/32 bit size for the hole.
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You are using a new crank sprocket right? I would use a dowel pin.
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Thanks for the ideas! Orcoaster, i think i may give your suggestion a try. It seems to be the least amount of work and doable with the engine still in the car. I think that with a new bolt, and a built up sprocket it may last for awhile until I decide to either ditch the car or do a proper TDI crank fix.
Now that I know what the signs are, change in timing,engine sound, harmonic balancer wobble, I am hopeing that I can somehow visually mark the crank sprocket/bolt and check it and retorque every lets say 500 to 1000 kilometers. Possibly squeek another few klicks out of it.
Coaster, have you tried this technique or had success with it? I have a basic wire feed welder and I am a very BASIC welder, would this be adequate?
Just out of curiosity, if one were to choose the dowel/pin fix, how deep or how far can you or should you drill into the crank nose?
just do it right... please?
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I think the dowel pin is more a preventative measure than a repair.
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Sounds like he is trying to do it right. He went with the pin not the tab build up idea I threw at him. What kind of softer rod could he use for the pin? Just some sort of steel rod? Maybe a tad bigger, 3/16 ths and take a flat off one side on a taper from front to back. That way it would go in and he could tap on it and drive in tight.
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Hey guys, have decided to pin the crank as I believe that will probably be best for my situation. I managed to drill the sprocket today and that went well, the crank was a little trickier but I managed to get it done.
Pix, please... if you have the time.
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I think the dowel pin is more a preventative measure than a repair.
x2
the dowel pins will be shot in no time..
look at the old air cooled bugs..
they had the flywheel pinned to the crank, and the fix was to get your crank drilled for 8 pins, rather than 4..
i think this is gonna be the same deal..
i would have done nothing besides the TDI crank nose mod... but thats me.
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The Dowel fix has been done in the 16v world for a while. The link I had was from a Scirocco guy that had done it, they started with 1 and ended up 4 dowels and the stock tab like what he has that is worn down. Those held, and the dowels I am thinking of should be almost as tough as the crank. Any Unbrako or Holocrome or even import dowels should be perfect for what this will do. I wouldn't do it though for no other reason than if I needed another sprocket, I would have to remake it. The TDI one I could buy another and be done. I have heard that even the TDI sprocket isnt quite enough in some TDI builds and they are using dowels on top of it too.
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The Dowel fix has been done in the 16v world for a while. The link I had was from a Scirocco guy that had done it, they started with 1 and ended up 4 dowels and the stock tab like what he has that is worn down. Those held, and the dowels I am thinking of should be almost as tough as the crank. Any Unbrako or Holocrome or even import dowels should be perfect for what this will do. I wouldn't do it though for no other reason than if I needed another sprocket, I would have to remake it. The TDI one I could buy another and be done. I have heard that even the TDI sprocket isnt quite enough in some TDI builds and they are using dowels on top of it too.
dowel pins in a TIGHT< FRESH setup would make sense..
pinning a setup thats already worn out, i would think that it will only be a matter of time before its loose again..
the injection pump takes ALOT of power in the upper RPMs..
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I'm thinking the bigger problem is the low rpms. The load is high but nearly constant at high rpm, but the shock loads of intermittent pulses at low rpm would put more shear stress on keys & pins, IMO. Case in point: the clutched alternator.
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It's always interesting to see what kind of discussion these topics will generate! Guys, I have researched this to the enth degree, were talking probably 10 hours logged on 50 different sites to establish the best course of action. Turns out like most things on the net, there are a million different opinions heading in different directions. Regarding the pin "fix", it sounds like there have been many successful REPAIRS! using the pin method on a worn gear/crank. Also, there have been many failures! I don't know the ratio, there are just too many variables in the equation to consider. Again this is the deal on MY car: I paid next to nothing for it, it owes me nothing, I am not nearly addicted ENOUGH, to rip the car apart spend another 500.00 or so just to put it back together and in 2 weeks loose the transmission or some other pricey component to end up right back where I am today. This is my 4th or 5th diesel "hobby" car. Mitsubishi,VW,Mercedes in the last 10 years, I am sure this one wont be my last. To the die hard purist enthusiast, I apologize in advance if my hack job "ghetto" repair has struck a nerve. To the others that are curious, risk management seekers, and experimental automotive hobbyists, let me be your official guinea pig on this one. I will keep everybody abreast of the situation, it may be a dismal failure instantly, or it may take months or even years to reveal the flaw. Either way the glow or the egg on my face will not emotionally scar me for life, ok maybe a day or two!
Ok moving on, here's the skinny, I have drilled the holes, was going to use the old gear but during my 9th hour of lost sleep decided against it, why would you? So will get a new one today and re drill. I visited an old machinist dude yesterday and he gave me some very bizarre nylon impregnated steel/ titanium, yes titanium, 5/32 rod, that's the size I drilled. Its military spec so dont ask! You can't cut this stuff with a cobalt band saw from the industrial revolution, but put it in a vice and it will bend with out shattering. Too hard, too soft, too pliable or flexible? Who knows, again (see above). So new gear, bolt, a dabble or 2 of JB weld just because, and hold onto your experimental automotive horses ;D.
I really appreciate all the experience of this site, you guys have been very helpful, the fuse has been lit and wether it fails or succeeds I think we will all take a little away from this.......look up definition,of FORUM you will see what I mean ;).
Stay tuned
Cheers
Wade
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Much appreciated, Wade.
Maybe I'm paranoid, but stuff like this makes me go look at my engine and ponder if I need to add each ounce of prevention.
This issue is probably endemic to the 1.6. There don't seem to be many options... take the crank to a shop, or pin it in the car. (Unless you live near Flagstaff.)
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Much appreciated, Wade.
Maybe I'm paranoid, but stuff like this makes me go look at my engine and ponder if I need to add each ounce of prevention.
This issue is probably endemic to the 1.6. There don't seem to be many options... take the crank to a shop, or pin it in the car. (Unless you live near Flagstaff.)
the broach isnt too terrible expensive, and neither is the fixture to hold the tool..
i think with all costs included, it would be less to have a tool fixture machined, and buy a broach, than to pull the crank..
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IDK broaches are expensive. I sold one last year it was 300.00 and it wasn't anything special.