Timing chains mk3...

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Originally Posted by Rob Burns

I understand that but the original post doesn't have enough information about why the poster wants to change the chain and reads (to me) as if the poster has been told the chain is a maintenance item. Every post after that seems to just assume that the car needs the timing chain replaced when that might not be the case. I just wanted to make the poster aware of that before they went and shelled out/budgeted for $2k for something that might not need doing after all.

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I think everyone here has a lack of understanding how the chains/guides etc work .
The guides should last 400,000km before they wear out , the chains never break , they stretch a little but you have hydraulic dampaners that keep it at a proper tension . Why do you need to replace the chains ? Well , the top chain is pushed by a bolt that has a spring in it . It works via hydraulic pressure from the oil system . What happens is over time or more so with lack of oil changes the pin inside the bolt gets clogged with old oil thats turned crusty , it eventually jams itself and pushes upon the top guide with more force than usual , the chain in turn is pushed against the guide harder and starts cutting into the guides , eventually breaking the rivets at the top of the guide followed by the bottom then it falls apart and starts running rough , occassionaly jumping teeth .

The biggest problem with doing the chains is the headgasket . Made of composite it just falls apart when you pull the covers off . Getting it back together without oil leaks is a hit and miss . One of the reasons why VW went with multi layered metal gaskets on the later VR6's

I've been preparing for this job for some time. I have started to collect the parts and think about ways of removing the engine. I really want to get the most our of this job so I plan to do a lot while the engine is out. My car has travelled over 250,000kms... 1994 Duel row chains.

What you'll need at a minimum.

Quality timing chain kit (year appropriate)
VW Sealant. (re seal gasket area and alloy cover)
New fly wheel bolts
New Clutch pressure plate bolts
New rear main oil seal (under fly wheel)
New rocker cover gasket.
New O ring for thermo housing.
Exhaust header gaskets.

Tools.

All the usual plus a holding device for the cams and locking device for the fly wheel.

What else I'm planning to do at the same time.

Renew clutch... New clutch kit and replace slave cylinder.
Fly wheel resurface or renew... Depends on condition and specs.
If OK clean and re-lube CV joints x4. If not replace... Renew CV joint bolts.
Replace front wheel bearings. (You need a press to get the CVs out.)
Pressure clean and paint engine block.

If you can afford it suggestions

Replace fuel lines from firewall x2 - Often cracking and perished.
Replace water pump regardless of condition. (relatively cheap)
Re new all engine mounts. OEM or after market your choice.
Change oil, filters and spark plugs.

Things to check

Alternator, Air conditioning pump, Power steering pump, Starter motor, Radiator and hoses etc.
Steering rack and tie rods.
Suspension bushes. (can be replaced with engine in place but you need to lift the engine to get one bolt out)

Some more for the list

Coolant... I prefer the VW G12+
Power steering fluid... Again the VW OEM works best for me.