ALH timing belt mishap, holy belt, oil on roller

So I just did my first timing belt change on my 2000 golf ALH. Along with turbo replacement and radiator replacement. Everything went fine for a week or so until a not backed off the timing belt tensioner. After the nut had fallen down before I found it I was attempting to determine thread size with another nut when it dropped. I then found the correct nut and installed/tensioned. I proceeded to forget about the draft night and continued with starting the car, then lots of smoke running horrible and found this .

https://lh3.googleusercontent.com/n...WkGLP7GoIy0G6WQAZh8gTry8HYmx5Yao=w834-h625-no
Today upon digging deeper I found oil running a little down the oil pan and on the bottom of the roller in the upper left of this photo.

https://lh3.googleusercontent.com/J...M-t84f7VoqDDmbcQ-_rT6jQUCFB4esF8=w834-h625-no
I did not find the culprit nut and not see any scarring marks on any of the pulleys which have less than 100 miles on them. I want to figure out where this oil could be coming from before I put a new timing belt on and put it all back together, any ideas?

Your pictures aren't showing up for me, (and I'm on a pc right now) but the only place oil can come from would be front main seal, head gasket, or cam seal.

If you can't find the nut, let er be for now, but I would tear the timing covers off all the way down to the crankshaft. I've seen what happens when a nut drops down to the crank and runs a groove right down the middle of the timing belt... Not a good time

The missing nut is a concern. But it could've also fallen out through a gap in the cover. All you can do take off all the components (rollers/tensioner/studs) and make sure it's not stuck between somewhere you can't easily see.

As for the oil stain, it could be the grease from the roller. If so, you probably should change out the roller. In fact, it's probably a good time to change everything out (rollers, tensioner, studs) since you don't know if the nut is stuck somewhere and if it managed to damage something when it fell off.

When you put everything back, make sure your torque everything down to spec. A nut should not fall off if properly torqued.

i have all the timing belt covers off currently, always seem to have a hard time getting photos to load here. I just finished the timing belt stuff last week i think, all the rollers etc have less than 100 miles on them, are you saying i should change them all out again? The TB tensioner backing out was my bad, i must have forgot to go back an TQ it down, and now im paying the price.
The line of oil down the side of the oil pan is new and the lower small roller ( between the crank cog and the tensioner ) had a drip of oil, although i had cleaned it off before i took the photo ( if the anyone can actually see the photo)

Funny, I can see your photos on mobile lol

Oil on that roller could be the seal failed. It doesn't hold much fluid. I'd pull it off and make sure it's ok.

And as for that belt... Holy cow big ol chunk missing. Talk about dodging a bullet. Yeah with the covers off to that extent, if you can't find the missing nut, I'm sure it's long gone.

3baudios said:

i have all the timing belt covers off currently, always seem to have a hard time getting photos to load here. I just finished the timing belt stuff last week i think, all the rollers etc have less than 100 miles on them, are you saying i should change them all out again? The TB tensioner backing out was my bad, i must have forgot to go back an TQ it down, and now im paying the price.
The line of oil down the side of the oil pan is new and the lower small roller ( between the crank cog and the tensioner ) had a drip of oil, although i had cleaned it off before i took the photo ( if the anyone can actually see the photo)

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I wasn't sure if you'd replaced it when you changed the belt. If it's new, then it's probably. I would still take everything off and double check everything for leaks/bent bolts though.


You really got lucky that you didn't have any cylinder head coverage.

Sounds like the nut got sucked between the crank pulley and punched a hole in the front main seal housing.

turbocharged798 said:

Sounds like the nut got sucked between the crank pulley and punched a hole in the front main seal housing.

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that is what i was thinking, i have a seal here but am not sure how to hold the FW to be able to remove the crank bolt, ill have to take some time to look it up

Apart from finding the oil leak, I don't see where you made sure the cam and pump were still properly timed. Likely not as shown by the horrible running you mentioned.

Check where they are before removing the belt. You need to know if you had piston/valve contact.

I have it timed with the fly wheel marks injection pump pin and camshaft lock tool

But was it still in time after the incident?

it seems to be, i rotated it with the belt intact to find TDC, was watching the injection pump slot and as it got close i went and looked for TDC on the FW and it was in the window and upon removing the vacuum pump the slot seems approx horizontal, im waiting for the new TB before i take the VC off so i can put the cam lock plate in to make sure it is exact. when it was running bad i had VCDS running and it was super retarded, which makes sense because i was just bringing the slot close to the alignment hole when the TCD mark came up on the FW

The margin of error on the cam/crank before valve contact occurs is about 7 degrees of crank rotation. That's NOT MUCH.....

If you "think" it didn't happen, don't verify it, and are wrong you're odds-on to drop a valve a few thousand to 10,000 miles down the road -- which is usually a wipe-out event.

Genesis said:

The margin of error on the cam/crank before valve contact occurs is about 7 degrees of crank rotation. That's NOT MUCH.....

If you "think" it didn't happen, don't verify it, and are wrong you're odds-on to drop a valve a few thousand to 10,000 miles down the road -- which is usually a wipe-out event.

Click to expand...

how does one check? compression? i was going to put a new belt on and see how it turns over(if it feels the same as it did before in regards to the ammt of force needed) has anyone had experience with this?

IMHO, since you're doing the timing belt already --

Once you have the cam sprocket off remove the cam (it's easy; it's just the caps) and look VERY CAREFULLY at the tops of the lifters. If you see ANY evidence of dishing or cracking -- ANY -- you had contact and the head has to come off.

If the camshaft and crank were out of time by ONE TOOTH when you first looked after the incident you *probably* had contact. If more than one tooth it's essentially certain you did.

Pretty much, the cam followers should be completely flat and smooth on the top.

Thank you for the help guys, i will hopefully have time to pull the cam tonight and take a look at the lifters ill take photos and hopefully be able to share them on here

ok, VC and cam are off, i cleaned up/wiped off the lifters and they all seem to be fine, no signs of scratches/dishing what have you.... i tried to take some pics (difficult with the shiny/reflective metal) did i miss something?
https://photos.app.goo.gl/99ei2Z4DEMj6hXUs7
https://photos.app.goo.gl/vuxBqoKonjq1xFse6
https://photos.app.goo.gl/dq4F593y3UiBkvmR9
https://photos.app.goo.gl/6hbnc2FtmSNspJtE6

The circular bits in the middle is normal wear, but if there was valve contact, there'd be dents there. Here's what an obviously bad one looks like. The flat line on the top is where the valve lobe tried to push down... But couldn't

I would say that if you were able to turn the motor over by hand it didn't go out of time enough for valve contact. It wouldn't have jumped time, have a valve hit then jump back.

Unless #1 was on its way up and you just finished half rotation to bring it to the top.

If the belt did slip it would be an exhaust valve that was hit.

Evidence of a hit would be cracks from the valve pushing up the center while the cam hit the edge of the lifter.

Edit: Like the picher above.

definitely don't look anything like those, they look just like normal lifters. What I think I'm going to do is put a new timing belt and turn over a bunch by hand to make sure everything feels ok, then i will have to replace the crank seal carrier, last night i saw where the missing nut went...took a photo this morning...anyone have a crank seal carrier?

https://photos.app.goo.gl/NP57ivfUZPq86Btt8

Looks like you dodged the bullet....

2.slo front covers are the same so plenty of good used one available. I would also replace that crank pulley as it likely got marred up from the nut.



You will need a holding fixture for the crank pulley. I made my own from a plate and a piece of pipe.

turbocharged798 said:

2.slo front covers are the same so plenty of good used one available. I would also replace that crank pulley as it likely got marred up from the nut.



You will need a holding fixture for the crank pulley. I made my own from a plate and a piece of pipe.

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i just spent $35 for one from ID parts with the new timing belt and bolt. A friend has a motor that has bent valves that i can hopefully pull the cog and crank seal carrier, ill have to talk to him

Make sure you replace the crank bolt too. Good luck torquing that in chassis....

Nero Morg said:

Make sure you replace the crank bolt too. Good luck torquing that in chassis....

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i have a new bolt ordered, with the cam out i should not have to worry about accidentally spinning the engine while torquing ( all the valves being up) still looking to get a crank seal carrier and possibly a new crank pulley

yesterday i removed the crank bolt, i was really worried about being able to get it out. I had read that i should be using a 3/4" breaker bar, but only had my 1/2" and did not want to break it ( obviously ). It came out rather easily, i made sure that TDC mark on the FW was still ligned up and now i will just be waiting for the new crank seal carrier to arrive to be able to button everything up and put back on the road

3baudios said:

yesterday i removed the crank bolt, i was really worried about being able to get it out. I had read that i should be using a 3/4" breaker bar, but only had my 1/2" and did not want to break it ( obviously ). It came out rather easily, i made sure that TDC mark on the FW was still ligned up and now i will just be waiting for the new crank seal carrier to arrive to be able to button everything up and put back on the road

Click to expand...

The fun part will be holding the motor from turning over while getting that bolt tight! I borrowed a homemade crank yank tool that bolts to the crank pulley and rests against the subframe. I was able to do it with a 1/2" breaker bar with a cheater pipe.

Or if you can get the engine low enough, use an impact. That's how I did the 90° over on the one I changed.

Use a hydraulic jack on the breaker bar. Easy peasy.