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Engine Specific Info and Questions => IDI Engine => Topic started by: 92EcoDiesel Jetta on June 19, 2009, 03:28:21 pm
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The Bently says remove the water pump pulley and 2 botls one nut securing the lower cover and remove cover. However, the crankshaft pulley and vibration damper is preventing that from happening. The Bently did not say it is necessary to remove the crankshaft vibration damper and pulley in order to remove the lower cover. What am I misssing? Does undoing the 4 socket head bolts remove both the vibration damper and pulley? Or do I have to remove the 12 point crankshaft bolt also?
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Do I need a puller to get it off? Is there a woodruff key?
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There is no key on the dampener. Take out the 4 bolts and wiggle it back and forth and it will come off. You may need to lightly persuade it with a rubber mallet
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The dampener is smaller in diameter than the pulley behind it. The pulley is bigger in diameter than the hole in the lower cover. How can the cover come out after removing the dampener? Confused.
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I don't think that you see it correctly. The v belt pulley will come off without the crank sproket comming off. Here is a picture of the pulley and the cover off, but the crank sproket still on there.
(http://i13.photobucket.com/albums/a269/libbybapa/Imag0339.jpg)
Can you see it now? At least I think I know what you are saying.
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The V belt pulley(s) and the damper are 1 piece.
The timing gear as seen above is behind the v-belt pulley/dampener and should be left alone. It's held on by the 12pt 19mm bolt.
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man, that picture makes taking that bolt out look easy. I broke two sockets, bent 1/4 inch flat bar steel, and lifted my car off the ground trying to undo mine... i guess mine was still in the car... perhaps that makes the difference...
anyways, ditto! no need to undo the bolt-of-death to fire that sucker off!
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Well, I wiggled it hard and it didn't budge. I hit it a bunch of times with a rubber mallet and it didn't want to come out either. I just sprayed lot's of penetrating oil in the sprocket bolt area and will try again in a short while. Any other tricks to get it out? Pry it out? I don't really want to damage the plastic cover.
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there are 3 fasteners holding the cover on, I don't know if you got them all. It will bend a lot, also the water pump pulley is a pain and I usually take mine off to get the cover.
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all 3 cover fasteners are off. you are correct that the water pump pulley has to come off to get to one of the fasteners. The problem I have now is getting the vibration damper off. It just will not budge from wiggling and beating from a mallet! What kind of a fit is the dampener? Is it a bushing? A taper? I see a hole in the dampener with what looks like a pin. Is that just a key to line up the marks?
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It was corrosion on the approx 3/16" thick damper hole where it goes over the 12 point bolt. Why did they make the tolerance so tight for corrosion to set it, unless it's load bearing? Why didn't VW use a timing chain instead of a belt? ??? And you have to do this PITA job every 60k miles? :o I would have gladly pay more for a chain. I am beginning to really appreciate the timing chain in my Mercedes 300D turbo. ;)
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And you have to do this PITA job every 60k miles? Shocked I would have gladly pay more for a chain. I am beginning to really appreciate the timing chain in my Mercedes 300D turbo.
The first time I did this I was cussing the whole way through.... Just have some beer handy, it helps. always does. lol
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Why did they make the tolerance so tight for corrosion to set it, unless it's load bearing?
It has to be centered exactly, since it's a pulley.
Why didn't VW use a timing chain instead of a belt? ???
Lots of good reasons... if you're interested "search" will turn up quite a few threads.
And you have to do this PITA job every 60k miles?
Use antiseize on all threads and surfaces, like the last guy that did the job could have done, and you'll be able to do a belt in less than an hour.
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Andrew, that's a good reason for using a belt. My next question is: Why is such tight tolerance between valve and piston ineeded?
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you need to have a high compression (23:1) for one simple reason, as found out by (should be your god) Dr. N. A. Otto in 1876. He found out that once you compress air in a cylinder so tightly (23:1), an extremely high temperature is produced. squirt just a little bit of that diesel goodness into that cylinder, and BAM......it burns almost immediately. This tiny amount of diesel is what makes our idi's get 40-50 mpg consistently. ;D
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Actually many diesels have significantly lower compression ratios 16-17:1. The 23:1 compression ratio was prescribed by the VW engineers to alleviate hard cold starting due to the heat loss of the pre-combustion chamber design. My mercedes diesels start just fine in the cold with significantly lower compression.
The Mercedes diesels (80's era) also has pre combustion chambers. What's so different in their (pre combustion chamber) design where one needs high combustion to start (in the cold) and the other does not?
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i wasn't trying to say that the original diesel founder detemined the 70's and 80's vw idi technology. just saying that any diesel motor is going to have a close tolerance between the pistons and valves. a little knowledge never killed anyone ::)