Author Topic: AAZ Broken timing belt (Read 6698 times)

jolotter · « **on:** September 26, 2007, 08:31:46 pm »

I just bought a 93 Golf including a spare 1.9 engine. The PO said the timing belt broke as he started it in the driveway and the engine died right away. Is there any chance that the valves arent all turned to pretzels? Should I pull the head with the engine in the car or should I just swap in the other used but supposedly good engine and tear the other one down later?

BTW the car also came with a new timing belt on the floor by the pedals. Wishful thinking?

Johann

Jetta Fan · « **Reply #1 on:** September 27, 2007, 04:27:50 am »

My timing belt broke on start up and, thankfully, the engine suffered no damage.

mk2diesel · « **Reply #2 on:** September 27, 2007, 08:42:41 am »

the valves are at right angles to the pistons .... chance of hurting the pistons is slim... slim chance of valve damage ... but most times the stem of the valve punches through the bottom of the lifters ....

follow the advice of Libby ... he's hit it on the head

jolotter · « **Reply #3 on:** October 01, 2007, 07:49:28 pm »

Well I got the car home this weekend on a trailer. Had a look today. Took the belt cover off. Timing belt not broken as PO said! Got the cam out. The valves all seem to be at the same height, lifters and cam ok. Back together and timing the pump. With the four bolts loose, the pump won't shift. Liquid Wrench... Hammer and a block of wood. Eventually, I got it to move but it was so hard that a) I was afraid of breaking the pump and b) the dial gauge kept slipping out from the shock. Anyway finally got it done. Checked it 4 times as it was so much trouble.

Next thing, the fuel lines (clear) are empty. When I get the charged battery in (tomorow?) I'll crank it over, see if I can get fuel through the system. A good search of the forum indicates that should do it provided there's no leaks, although I suspect there are since the lines are empty.

More to come.

This is distracting me from my TD van project.

Johann

jolotter · « **Reply #4 on:** October 02, 2007, 05:35:00 pm »

Well this morning I put the battery in, cranked it over and got a loud metallic bang! I took a deep breath, went to check if maybe I had left a tool in one of the timing belt gear holes or maybe the IP lock pin in. Nothing bent or broken visible. So I tried again. Bang! Another deep breath and that sinking feeling. Still couldn't find anything wrong, so I put it in gear and rocked the car back and forth. Everything seemed to turn fine as I bumped it along so I tried the starter again. This time it turned over like a real car!

So after cranking it quite a few times, the fuel lines were filled with only small bubbles but no start. i cracked the injector lines and got fuel leaking at them all. Still no start. Tomorrow I'll check the glow plug circuit and see what's what.

Johann

burn_your_money · « **Reply #5 on:** October 02, 2007, 10:37:04 pm »

maybe you should drop the pan and have a gander in there so see what all that racket is about? I'd be pretty hesitant to keep on cranking

jolotter · « **Reply #6 on:** October 03, 2007, 06:40:01 am »

After rocking the car to make sure everything was free, it turned over smoothly on the starter. I also did quite a few revolutions with a wrench while setting the timing. While I don't know what it was, I'm guessing maybe the clutch was stuck or something?

I'm out to check the glow plugs

Johann

jolotter · « **Reply #7 on:** October 03, 2007, 06:12:43 pm »

So two of the glow plugs showed infinite resistance so AI swapped them with two from my spare engine. The two oroginal plugs showed a resistance of 1.2 Ohms (maybe the decimal is wrong) and the two I swapped in showed about 0.8 Ohms. Is that close enough? They all glow red and none showed signs of dripping injectors. Does the resistance denote fast or slow? THey all have brass contacts.

So now when I crank it over with jumpers to a running engine's battery, it coughs regularly like it wants to start but can't quite make it. Any suggestions? Maybe the compression is low. I don't have a diesel compression gauge - yet. I think tomorrow I'll recheck the timing and hope for the best.

Johann

jolotter · « **Reply #8 on:** October 03, 2007, 07:36:05 pm »

Ha! When I first read it, I read Vroom-de-vroom.

Unfortunately I'm not even at Vroom, die, vroom, die. More like regular dry cough. Humph.
I'll try it anyway.

I've got WD-40. What's PBBlaster?

Johann

jolotter · « **Reply #9 on:** October 05, 2007, 03:33:59 pm »

It lives! This morning with a freshly charged battery, I cranked it over and it started right up. Ran rough for about half a minute then smoothed out. My first running diesel!

So yesterday I rechecked the timing and it was way off. No wonder it wouldn't start. I guess when I tightened the tensioner, there was slack on the other side of the loop. So I did it all again and Bob's your uncle. I also discovered what that terrible clanging noise was when I first tried to start it a few days ago. I was looking for my breaker with the 19mm on it to loosen the camshaft pulley. Where was it? Well I found it under the car. I had forgotten to take it off the crankshaft bolt before and that's what made all the noise. :oops: At least nothing bent or broken, (except my pride.)

One issue. It seems to run smoother with the cold start pushed in. Does that make any sense? It's timed right at 0.8mm. Is there an old worn pump timing adjustment I should take into consideration?

Thanks for all your help, Andrew.

Johann

Patrick · « **Reply #10 on:** October 06, 2007, 03:14:08 pm »

To heck with the factory timing. Both you and the car will be a lot happier at 1.00 mm or even 1.05..........

Vincent Waldon · « **Reply #11 on:** October 06, 2007, 06:17:54 pm »

2X on the recommendation to replace the crank bolt if you think there's any way it might have been loosened slightly... AAZ engines are really "cranky" about the crank: bolt/sprocket/harmonic balancer... ha ha I slay myself.

And yes, my experience is that most diesels prefer being closer to 1.00mm than the original setting... just triple-check that you have the cold start knob pushed all the way in when you set the timing.

jolotter · « **Reply #12 on:** October 07, 2007, 07:30:55 pm »

Is the AAZ (1.9) pump the same one as the MF (1.6) pump. And are they timed the same? ie. is 1.00mm advance good for both of them?

Andrew, I locked the camshaft and pump when I retensioned the belt, and only then reset the injection timing, so it's for sure right on.

I will check the torque of that crankshaft bolt and replace it if it's loosened. Thanks. Is the crank bolt failure related to the wobbly gear and subsequent mod, or does the gear wear the keyway simply from more torque than it's engineered to withstand?

jolotter · « **Reply #13 on:** October 15, 2007, 08:45:01 pm »

I replaced the crankbolt today. Thanks for the advice you guys. 20 years ago when I started dabbling in engines, I only had one guy some weekends to help me out. It's amazing, the combined knowledge available to us all. (Deep sigh and look at the stars.)

Im feeling better now. But my car isn't! :x

Since getting the car running, I've only had it out a couple of times. The first time out I took it for a run on the highway. Moving off from a standstill was really hard. I really had to rev it up and baby the clutch. One it was going it felt ok but not what I was expecting. No smoke really, unless I floored it then a big cloud. Fine on the highway but again, the first time I floored it then looked back I was shocked and embarrased by the cloud of soot there. Back on the city streets it started to heat up so I quickly drove home with the heat blasting, which kept it cool. The whole t ime, as soon as the revs increased to a good pulling range, (no tach,) it would ping really badly.

It was timed and checked at .80

Today I chased some electrical gremlins. Got the rest of the lights working and the rad fan going. Decided from reading many posts to advance the timing to 1.00 to see how that helped the situation. Well after charging up the battery, again, I tried to turn it over. It was bucking like a bronco. Tried a couple of times but quickly stopped. It never started, but cranking it over it feels like its so advanced that it is trying to force the pistons back down.

The camshaft is locked with a file and shimed under the ends, the IP is locked, and the crankshaft is on the TDC mark. Cold start is pushed in. Since it ran before, I must be close.

Stop the presses! I just checked the gauge and the extension pin that rides on the IP lobe was not threaded tightly enough into the next part, allowing a fair amount of wobble at the end of it's 10 cm. Now that it's tightened, I'll time it again tomorrow and also see what it's currently set at.

Johann