Recovering From The Crash

Hi All,

I lost time on my MK3 1Z engine due to a previous owner re-using the crankshaft stretch bolt. I am working with a local mechanic to put this all back together and could use some guidance on the plan.

For the head, the lifters are being replaced and my very rare 8mm valves are being replaced with 7mm Intervalve intake/exhaust valves and OEM valve stems. The machine shop says this can be accomplished by just replacing the valve guides. The camshaft looks ok, but I am putting in a brand new OEM replacement just to be safe. I had a temporary detour by purchasing some 8mm valves from a German shop that don't fit and it looks like I will probably have to eat that cost.

I am planning to buy the replacement harmonic balancer (028 105 243). Mine is definitely the old style without the rubber on top. I'm looking at eBay listings and some say Febi is the OEM and others say Vaico. Which one should I buy?

I have records the water pump was replaced very recently, so I'm going to skip that. We have the old timing belt, but will be putting a new one on along with idler roller and tensioner roller.

Can the head bolts be reused or is there any value in buying new head bolts?

One of the howtos mentions replacing the tensioner rod and the serpentine tensioner. Do these affect the timing belt or engine operation? Can I replace them by myself later?

The last part that concerns me is that I do not have a working computer interface. There is power to the OBD port, but some connection issue. I have tried generic OBD scanners and a VAG-COM. The mechanic is mentioning to time it without VAG-COM. He is a skilled mechanic, but not a TDI guy.

Is there anything else I should be concerned about or parts to replace or check while everything is still apart?

h.ubk

I can't answer all your questions, but I'll take a crack at some of them.

h.ubk said:

Can the head bolts be reused or is there any value in buying new head bolts?

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What does the Bentley say? If you don't have one, look on eBay. However, I would be astonished if Bentley said you could reuse them. They are probably stretch (torque to yield) bolts that are one time use only.

h.ubk said:

One of the howtos mentions replacing the tensioner rod and the serpentine tensioner. Do these affect the timing belt or engine operation? Can I replace them by myself later?

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Yes, these can be done separately. While you're at it, I would install a clutched alternator pulley as well (Gates 37010P; and you'll need a special tool such as MetalNerd MN3400 to pull the old one off).

h.ubk said:

The last part that concerns me is that I do not have a working computer interface. There is power to the OBD port, but some connection issue. I have tried generic OBD scanners and a VAG-COM. The mechanic is mentioning to time it without VAG-COM. He is a skilled mechanic, but not a TDI guy.

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You set mechanical timing on a TDI without using the computer interface, but then you must set injection timing, which DOES require the interface along with VCDS. You can guess, and the car might run, but you won't get proper power and fuel economy.

What does the Bentley say? If you don't have one, look on eBay. However, I would be astonished if Bentley said you could reuse them. They are probably stretch (torque to yield) bolts that are one time use only.

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Thanks, the Bentley is in the car with the mechanic. After doing some research, I'm pretty sure they do need to be replaced.

Yes, these can be done separately. While you're at it, I would install a clutched alternator pulley as well (Gates 37010P; and you'll need a special tool such as MetalNerd MN3400 to pull the old one off).

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Great, I think I'll do these myself later.

At this point, the most pressing issue is why the crank bolts have failed three times. Apparently, they failed twice for the last owner. The only things I can come up with is that the previous owner used Febi crank bolts and I will be using OEM. Also, I have a new harmonic balancer, although I am not convinced this would cause the bolt to snap. Another possibility is they were not properly torqued. I am thinking about finding an ARP bolt and spending the extra $$ as I really can't afford to do this twice.

h.ubk

Well, I finally got my car back. I have never been this overwhelmed with a car before with the lack of parts availability and people who have experience with them. It took literally two months to get all of this together and I spent a ton of time trying to get the right parts and figure out how to do this.

A local machine shop surfaced the head and replaced the lifters. I bought 8mm intake and exhaust valves from a store in Germany, waited three weeks for shipping and then found they did not fit. 8mm valves are unobtanium in the US. The machine shop said they could not do the conversion to 7mm. I then sent it to another rebuilder that has rebuilt a bunch of TDI heads and they said my glow plug threads were mostly stripped and it would be leaking diesel. I paid $120 just to ship it there and back.

Eventually, I ended up buying a complete OEM new head with valves -- this after already buying a new camshaft and another set of new valves. So, now I have my old head that is probably rebuildable by someone who knows what they are doing, an extra set of 7mm valves and another set of 8mm valves.

I changed all of the pulleys. I believe my harmonic balancer was the old style and the clutch pulley on the alternator were the old style previously. Aside from this, I'm nearly certain this whole mess was because the last mechanic put the crank bolt on dry and did not properly tension it.

The IP timing is still not set but the car runs better than it did before. It seems to have more power up hills. Why does the IP timing need to be set when nothing has changed with the IP? Is this just an interval for maintenance or because something was altered in removing the cambelt?

Shortly before this incident, the power steering pump failed. It had 350,000 miles so I figured it was just time. But, when I put the new one on, it just wouldn't stop squealing as I turned the steering wheel and it didn't matter whether the belt was tight or looser. Yes, it was bled and there was power steering fluid. When I got the car back, there is zero squeal from the power steering and I can't get it to make the noise again.

Another oddity I had before was when I put the car into reverse, it really started moving backward quickly. I wasn't sure if this was normal for a TDI, but I usually had to ride the clutch while hitting the brakes. Right now, the car will reverse like a normal manual transmission car. Can anyone explain this?

h.ubk

Thanks for posting an update -- really appreciate it.

h.ubk said:

The IP timing is still not set but the car runs better than it did before. It seems to have more power up hills. Why does the IP timing need to be set when nothing has changed with the IP? Is this just an interval for maintenance or because something was altered in removing the cambelt?

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The mechanical timing sets the valve timing in relationship to the crank. The injection timing is dependent on the mechanical timing setting, and it can also vary a little with belt stretch, etc. It also changes a lot if you switch out injectors. I've always found that if I mess with anything related to the TB, I have to re-set my injection timing.

Interesting. So, I called a local mechanic who had a Vagcom and they wanted $115 to set the timing. I was able to get the eBay cable and VCDS lite for less, so I did.

According to VCDS Lite, I was only able to get the coolant temp to 173 deg F. This is after I ran the A/C for about 15 minutes on a relatively warm SoCal day and then drove up a large hill. The injection timing was just about perfect. The line hovered just above the blue graph. I'm almost disappointed -- I had my wrenches out and was ready to start adjusting.

I'm looking into camshaft timing right now. My new head has a new camshaft so it would be nice to check it. I saw a Youtube video about setting cam timing, but it featured a newer TDI and I was unable to find torsion values or anything that looked like cam timing.

h.ubk

The cam timing is set with a holding tool when the belt is installed.

Steps are: cam lock in place, cam sprocket loose, pump pinned, crank at TDC, install belt, remove pump pin, tension belt, verify crank position, torque cam sprocket.

So if the mechanic did it properly there's no adjustment to be made on the cam.

I believe the instructions on this site have you leave the pump pin in during tensioning but that is incorrect.