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Engine Specific Info and Questions => IDI Engine => Topic started by: Rabbit TD on March 18, 2009, 11:02:13 pm
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I discovered something yesterday that everyone should be aware of and is probably causing problems for some of you right now. I was taking my N/A pump off the old engine that I just pulled {great little engine} to use on my T/D till I get it rebuilt or re-sealed at least. Just for the hell of it I thought I would see how far the timing might have changed over 3 years now since I set it to 1.0. I already hade the valve cover off to use the bbaffle in the T/D engine and rotated the engine till #1's valver were up, locked the cam in back and the pin dropped right in the pump pulley hole but the crank mark for 0 tdc was no way in sight, about a quarter turn away. I thought WTF this can't have ran like this for 3 years, wouldn't last 3 seconds. I double checked this numerous times and then it hit me. Last Summer I put a clutch in this car [Rebuilt Autozone} and it bolted right up no problems and trans slid right in place fine and I adjusted the cable and all was fine. This one has crank holes that only go on 1 way and the pressure plate's holes for the flywheel are the same so you can't get wrong, only they can'. This pressure plate had to have been assembled with the crank and flywheel holes not being located correctly throwing the timing mark off as it was about 1/4 turn away before I found it. Since I was just changing the clutch and the motor was fine I never noticed anything then but if I had tried to time the engine I would have had a hell of a time figuring it out.
I went ahead and pinned the pump with #1's valves up, locked the cam with the file I use and just made a punch mark on the crank where it was at that point. I set up my pump indicator, rotated backwards, 0'd the gauge when the needle stopped and rotated to the punch mark and it was right on 1.0 where I set it 3 years ago. point is I'll never trust a flywheel mark again, the only way you can tell if it is right is to either have the head off with the trans and flywheel on, stick something in the injector or G/P hole or also make a mark on the crank pulley with a detachable pointer during assembly which luckily I did on the T/D engine while I was doing the piston projection check. With all these parts being rebuilt all over the world you don't know what you are getting today and it's getting worse all the time. I can hear some of you right now saying {the Dumb ****** probably just put the flywheel on wrong} but they only go on I way unless maching or something else was changed and this one bolted up fine when you get the right spot with no problems and trans went on far enough, no tight spots. This is probably causing a lot of people problems especialy a poor new guy trying to do his first clutch change and putting a timing belt on at the same time if he gets one of these f'd up Autozone or other versions that are possibly not assembled right, imagine the mess that would make if the engine wasn't hand rotated first to doublecheck and this is a good example of why it should always be done.
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G60 flywheels bolt right up but the timing mark is wrong for our engines, you should have checked this when assembling.
as you say, when in doubt, take an injector out and find true TDC, then scribe a new timing mark as you did
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G60 flywheels bolt right up but the timing mark is wrong for our engines, you should have checked this when assembling.
as you say, when in doubt, take an injector out and find true TDC, then scribe a new timing mark as you did
Its really surprising that German engineers would miss something as simple as the fly wheel bolt pattern not being symmetrical, or at least have a dowel pin to locate TDC marks. Must have been a junior engineer right out of college and no practical mechanics experience. Reminds me of the Chevy a few years back there you had to pull the engine to change the spark plugs.
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How about the Chevy Venture vans a few years ago where you had to remove the airbox and something other held in by like a dozen bolts just to jump the battery.. like what the hell were they thinking? lol
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G60 flywheels bolt right up but the timing mark is wrong for our engines, you should have checked this when assembling.
as you say, when in doubt, take an injector out and find true TDC, then scribe a new timing mark as you did
Its really surprising that German engineers would miss something as simple as the fly wheel bolt pattern not being symmetrical, or at least have a dowel pin to locate TDC marks. Must have been a junior engineer right out of college and no practical mechanics experience. Reminds me of the Chevy a few years back there you had to pull the engine to change the spark plugs.
quite off topic, but i thought that was the 70's mach 1 mustangs with big blocks in them that had to have the engines pulled to change plugs? maybe im wrong.. man, i love how often i have to change the spark bolts in my rabbit. :)
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Its really surprising that German engineers would miss something as simple as the fly wheel bolt pattern not being symmetrical, or at least have a dowel pin to locate TDC marks.
Not surprising at all, really. They did that for a reason, so that if you remove the original flywheel (to change a clutch) you can only install it one way and therefore preserve the timing marks. Doesn't make as much of a difference on the 02A and 02J trannys since the flywheel is on the "correct" side instead of flipped.
But now a days, with people swapping flywheels between all different types of cars, it obviously makes sense the timing marks can get screwed up. The Bentley manuals inform you of this and describe the proper way to re-mark the flywheel for proper timing in the event that you are replacing the flywheel. I had to do this very thing on my '84 scirocco since someone swapped the flywheel with a different car and the timing marks were wrong.
In my opinion, it was a very smart way to key the flywheels. What about the GM symmetrical flywheels that were for externally balanced engines? Now that was a stupid idea and poor engineering.
Brendan
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what is the proper way to re mark your flywheel? ive got a 210mm unit on my diesel, and i didnt realise, until i got it all bolted in and running, that the flywheel was from a gas engine. and im pretty sure they have a 6* timing mark and thats it.
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what is the proper way to re mark your flywheel? ive got a 210mm unit on my diesel, and i didnt realise, until i got it all bolted in and running, that the flywheel was from a gas engine. and im pretty sure they have a 6* timing mark and thats it.
The gas engine flywheels had marks all over the place. My JH was I think 12* before TDC, but a mid-year change made the mark something like 3* ATDC and the timing procedure was all different. :roll: You'll have to check the Bentley manual, I can do it when I get home if you don't have one. Easiest way if the flywheel is on the car already is to go ahead like the OP did and find true TDC with the pump/cam/piston and then mark it, but off the top of my head I don't know if the factory diesel flywheel mark is right on TDC or not.
Brendan
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im 99% positive that the marks on a diesel are tdc straight up. thats how it seems when you have the head off an engine with known diesel parts that times perfectly. this wheel is off a 92 EFI gasser. i dont have a bently either, but i wish i did.. so basically just take an infector out and find TDC that way? i kinda have a feeling this is why my pump has to be all the way retarded and still not be retarded enough.
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im 99% positive that the marks on a diesel are tdc straight up. thats how it seems when you have the head off an engine with known diesel parts that times perfectly. this wheel is off a 92 EFI gasser. i dont have a bently either, but i wish i did.. so basically just take an infector out and find TDC that way? i kinda have a feeling this is why my pump has to be all the way retarded and still not be retarded enough.
My current 1.6 has the factory mark at TDC - when I pulled the head, I used my dial indicator to verify this from the #1 piston. My last 2 IDI's also had it at TDC.
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I put a gas flywheel on my 1.6n/a , but 1st with the new belt and tentioner on and diesel flyweel i timed the pump and noted tdc mesurment,them put on gas flywheel and sent pump to same measurment as noted and marked tdc onto the gas flywheel for the future.
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see, i didnt think about that when i had the damn thing apart. now im stuck with a useless timing mark and a car that runs OK. it would probably run a hell of a lot better with proper timing marks.
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According to my Bentley A2 manual, we are supposed to make our own mark on the flywheel. It says this applies to gasoline flywheels butt, I would check it on all. I really don't think this was an Autozone, napa etc problem. VW does all sorts of weird things like this, like what is up with that camshaft sprocket without a key and keyway ??? :?
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G60 flywheels bolt right up but the timing mark is wrong for our engines, you should have checked this when assembling.
as you say, when in doubt, take an injector out and find true TDC, then scribe a new timing mark as you did
This is just the standard flywheel that was on the old Rabbit that was fine and the timing mark was right, I totaly rebuilt that engie also 3 years ago and used that mark numerous times experimenting with timing positions, removing timing belts ect. and was correct until the flywheel was taken off and an Autozone rebuilt clutch installed by me and it bolted up {only one way] but the pressure plate moved the tiimg mark by not being indexed right during its rebuild. I never noticed till I rechecked pump timing the other day when taking the pump off.
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G60 flywheels bolt right up but the timing mark is wrong for our engines, you should have checked this when assembling.
as you say, when in doubt, take an injector out and find true TDC, then scribe a new timing mark as you did
Its really surprising that German engineers would miss something as simple as the fly wheel bolt pattern not being symmetrical, or at least have a dowel pin to locate TDC marks. Must have been a junior engineer right out of college and no practical mechanics experience. Reminds me of the Chevy a few years back there you had to pull the engine to change the spark plugs.
It's not VW's fault at all, it's some of the cheaper rebuilt parts you can get today at different places that evidently don't know that they have to be assembled keeping the marks lined up. This is my main reason for these posts to let people know especialy new ones to this hobby some of the things that can actualy ruin an engine that was built right and end up thinking they did something wrong themselves. Again always hand rotate first who ever reads this. Luckily all I did at that time was change the clutch and at that time it didn't matter where the mark was, just so it bolted up which it did.
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Its really surprising that German engineers would miss something as simple as the fly wheel bolt pattern not being symmetrical, or at least have a dowel pin to locate TDC marks.
Not surprising at all, really. They did that for a reason, so that if you remove the original flywheel (to change a clutch) you can only install it one way and therefore preserve the timing marks. Doesn't make as much of a difference on the 02A and 02J trannys since the flywheel is on the "correct" side instead of flipped.
But now a days, with people swapping flywheels between all different types of cars, it obviously makes sense the timing marks can get screwed up. The Bentley manuals inform you of this and describe the proper way to re-mark the flywheel for proper timing in the event that you are replacing the flywheel. I had to do this very thing on my '84 scirocco since someone swapped the flywheel with a different car and the timing marks were wrong.
In my opinion, it was a very smart way to key the flywheels. What about the GM symmetrical flywheels that were for externally balanced engines? Now that was a stupid idea and poor engineering.
Brendan
This was the original flywhel and I used the mark lot's of times to set timing, nothing changed till an Autozone clutch was put in last Summer, pressure plate relocated the flywheel position during it's rebuild process.
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im 99% positive that the marks on a diesel are tdc straight up. thats how it seems when you have the head off an engine with known diesel parts that times perfectly. this wheel is off a 92 EFI gasser. i dont have a bently either, but i wish i did.. so basically just take an infector out and find TDC that way? i kinda have a feeling this is why my pump has to be all the way retarded and still not be retarded enough.
My current 1.6 has the factory mark at TDC - when I pulled the head, I used my dial indicator to verify this from the #1 piston. My last 2 IDI's also had it at TDC.
That's why from now on I will always make an acurate pointer and put a mark on the crank pulley also for verification in case a pressure plate or flywheel is ever changed in the future.
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see, i didnt think about that when i had the damn thing apart. now im stuck with a useless timing mark and a car that runs OK. it would probably run a hell of a lot better with proper timing marks.
That's one of my main points about this post, to let some of us know that mark can actualy be off and timing might not really be where you think it is and wonder about tuning problems instead.
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According to my Bentley A2 manual, we are supposed to make our own mark on the flywheel. It says this applies to gasoline flywheels butt, I would check it on all. I really don't think this was an Autozone, napa etc problem. VW does all sorts of weird things like this, like what is up with that camshaft sprocket without a key and keyway ??? :?
No it's not Autozone or Napa's fault, it's these companies that rebuild theese things for them that evidently don't have a Quality Control metod like a jig to check these things that would make sure they were located right after assembly or different parts from different types of pressre plates are combined which weren't designed to have the marks in the same place. How many other vehicle use this reverse method of pressure plate and flywheel set-up? I doubt if they even know it's an issue in a lot of cases at these rebuild facilities and God only knows where some of them are today.
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what is the proper way to re mark your flywheel? ive got a 210mm unit on my diesel, and i didnt realise, until i got it all bolted in and running, that the flywheel was from a gas engine. and im pretty sure they have a 6* timing mark and thats it.
The very most acurate way is to measure piston projection on a dial indicator when the head is off, the second is to use something in the injector or G/P hole that can work like pump timing tool which I would do on number 4 as the piston is in the same place as no. 1 but be sure # 1's valves are closed with the lobes up. It will be hard to hold the indicator while trying to turn the engine to get it exact by yourself as the tool would have to be held very steady or somekind of a combination of a welding magnet and visegrip combination type of holding tool improvised. If You are 100% sure the engine is mechanicly timed right from previous check beore a flywheel or clutch change then just put the cam lock in with number one's valves in the right place, put the injector pump pin in and see where your pump is in relation to it's little pointer on the belt end, should be pretty close to the center even at 1.0. If you are positive the crank is at TDC then use a punch or chisel and make your own mark right at the pointer on the trans., you have to be 100% sure it is there before you do this though. If you are satisfied the cam and crank are aligned and the pump doesn't have enough movement to put it where it needs to be to be able to insert the pin with the pumps indiator marks centered then you have to move the pump cog a tooth one way or the other. Loosen the cam pulley to make this easier as it isn't keyed to the cam anyway,just enough to let the pulley slip on the cam. The pulley will stick to the cam so after you loosen the bolt about 1 full turn or so take 2 scredrivers and drive them in aroud the pully at the center as close as possible to the head and as close to 180 degrees apart as you can, drive them in snug with a hammer just do't go crazy doing this Then with the cam pre-loaded to the pulley side of the engine then hit the bolt with a hammer making sure the screwdrivers are always tight after every hit and the pulley will pop and you won't be driving the cam backwards enough to hurt something. Obviously the belt tensioner hasto be loosened first and I should have mentioned it first before any of the adjustment procedure starts and the crank should be marked first as well, very mportant. Once you have the engine positively timed with the crank right, the cam locked on #1 and the pin in the pump and centered on its marks then tighten the tensioner while the cam pulley is stll loose enough just to be able to spin but not wobble. This method keeps the crank from creeping away doing this, then tighten the cam bolt. Now time the pump in the normal method and if the crank actualy is right the motor should run good if you have no other problems compression or fuel deliverywise. Good Luck and make damn sure the crank is where it is supposed to be befor you make your mark on it, most important part of this whole process. :wink: