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Offline Cole

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There is a lot of *random* information out there on Eurovan timing chain, oil screen, slugging, tensionors and cam sensors. Let's compile some of the great write ups into one good place for easy Q&A to help others!
Cole

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Offline Micah

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Re: The Ultimate guide to timing chain issues, diagnosis and repair!
« Reply #1 on: May 20, 2015, 12:02:07 pm »
Good timing! I'm currently tearing down my '99 MV to do the chains. I've pulled the intake, and have the valve cover ready to come off. I am curious what the easiest way to separate the engine from the transmission is, and how much room you need to do the lower chain. I do not plan on taking the engine out.

Any input on this?

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Offline albertr

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Re: The Ultimate guide to timing chain issues, diagnosis and repair!
« Reply #2 on: May 20, 2015, 12:36:19 pm »
Take a look at the pictures posted on the following thread over @ vwvortex:
http://forums.vwvortex.com/showthread.php?5890626-Good-DIY-write-up-on-24v-timing-chain/page2

That might give you some ideas.

I will try to consolidate some of my old posts from that forum thread and re-arrange them in a proper order... if I ever have time for that.

-albertr
 

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Offline Micah

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Re: The Ultimate guide to timing chain issues, diagnosis and repair!
« Reply #3 on: May 20, 2015, 01:32:55 pm »
Thanks for the link!


Sent from my iPad using Tapatalk

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Offline Cole

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Re: The Ultimate guide to timing chain issues, diagnosis and repair!
« Reply #4 on: June 25, 2015, 03:36:08 pm »
Ok - almost the last of the engine component comparisons. I'm eager to start piecing things back together.

Picked up some new, OEM timing chain guides from my local dealership. After looking at online suppliers -- this worked out to be about the same price for the 5 components when I factored in shipping, duty and exchange rates. I'm not exactly thrilled to spend approximately $200 CDN for what amounts to 5 pieces of plastic (OEM chains would have been another $125-150 CDN).  >:(

New Parts




In the comparison of the timing guides - all showed chain contact wear - channels/grooves in the plastic. With the guides from the good BDF - the channels are usually visible, tight/straight, but barely/faintly perceptable by touch. Lucille's (AXF) upper guides were always the worst condition - grooves showed a lot of lateral play and wear on guide - making the depth of groove hard to perceive. The AXF's lower guides were generally in better shape -- deep grooves but straight. The other garbage BDF's guides were almost always nice and straight, with deep pronounced grooves. I tried to use my callipers to get some more empirical data, but it's not the right tool.

Chains

From Top-Bottom: Good BDF, Bad AXF, Ugly BDF

Chains -- by my eyeball and comparison were all very much the same length. I used a calliper in spots (such as the space between pins) and the results were consistently even on all the chains. One interesting note here -- is you can see that the upper chains from both the BDFs have some coloured links in them (to help count 16 rollers?) -- where as the AXF does not. I'm trying to determine if Lucille's had the chains done at all -- this could be a clue that it has. HAs  anybody else had a coloured chain link from their AXF?

Upper Right Guides

From L-R: New Guide, Good BDF, Bad AXF, Ugly BDF


From L-R: New Guide, Good BDF, Bad AXF, Ugly BDF


From L-R: Good BDF, Bad AXF, Ugly BDF

Top Left Guide

From L-R: New Guide, Good BDF, Bad AXF, Ugly BDF

Top Guide

From L-R: New Guide, Good BDF, Bad AXF, Ugly BDF

One thing I noticed with all this -- the disproportionate cost of the small upper guide. For it's size and complexity, it was considerably more expensive. I also noticed that this item is not always carried by the typical online suppliers -- and the reason why is that VW doesn't make this part or the cam phaser assembly.  :o

Lower Tensioner/Guide

From L-R: New Guide, Good BDF, Bad AXF, Ugly BDF
Here you can see Lucille's AXF guide which snapped when I tried to loosen the the intermediate sprocket retaining bolt.

Lower Chain Guide

From L-R: New Guide, Good BDF, Bad AXF, Ugly BDF

Here you can see the guide from the Good BDF snapped -- these are very brittle -- and three of the used guides had at least a hairline crack in them along the back. Sorry no decent picture of this.

Intermediate Sprockets

From L-R: Good BDF, Bad AXF, Ugly BDF


Close up of Bad AXF sprocket wear.

All showed about the same amount of wear on the bigger sprocket that connects to the lower chain. This makes me think that the lower tensioner works very well -- steadily applying pressure to the chain.  Where as the smaller sprocket from Lucille's AXF showed a lot of wear. The AXF also has the stiffest upper tensioner bolt -- which I think allowed more chain play -- and hence greater wear on the upper components.
Cole

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Offline Cole

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Re: The Ultimate guide to timing chain issues, diagnosis and repair!
« Reply #5 on: June 25, 2015, 03:37:10 pm »
Cam Phaser Module - you ask? Yes, if you noticed that cam phasers and the upper timing guide had a unique name stamped on to them: Hydraulik Ring. If you google it, eventually you will come to Hilite International's page here: http://www.hilite.com/products/engine-products/camphaser-modules.html  ;)  Good to know -- as this could help others find a replacement for the delicate cam phaser oil filter screen, or even a cheaper source for the upper chain guide.

Anyhow I pulled the cam phasers off of the engines -- I was just too curious about the screen condition. Something that probably everyone should at least check if they are deep into a timing chain job. Note, I also looked at the MK4 Jetta/Golf Bentley at this -- and the four bolts that hold the cam phaser housing on to the head are not stretch bolts. In some diagrams - they are referenced as "always replace" and in others there is no mention. The stretch bolts here are the ones that go through the cam phaser hub/sprocket and connect to the camshafts -- and then the large bolt that secures the intermediate sprockets.

Anyhow, the pictures...

Good BDF

Clean!  :)

Bad AXF




Busted screen. I later found small pieces of the screen inside the control valves.

Ugly BDF

Filled with metal shards - but intact!  :o

Is this good evidence that sludge is what busts through the screen on these? That filter mesh is so fine -- I could see it reaching a point where it is so full of sludge that the incoming oil pressure just blows itself through the screen.

FWIW - I also compared the cam phaser sprockets. There was evidence of wear - but generally all very even and nothing like the AXF intermediate sprocket.
Cole

Re: The Ultimate guide to timing chain issues, diagnosis and repair!
« Reply #6 on: November 02, 2019, 09:27:23 am »
Hi Cole. Great stuff here. Is the chains & guides replacement a service you do for other E Van owners? Eurovan are a puzzlement to repair shops here in the Chicago area.
Spencer