bebbetufs

Hi folks.
I finally got my car fired up yesterday, and to my horror the timing belt is still tracking towards the block and riding the tensioner pulley flange. The car in question is a 944 t. 1990 my. I've only run it 500km since I bought it in 2009, partly due to this problem.

I am absolutely perplexed by this. I have checked everything several times and I still cannot work out what is causing it. Please chime in with your thoughts and advice.

This is the story.
I bought the car with no reckord on the t-belt so first thing I did was to change it and the front seals of the cam and balance shafts. Skipped the main seal.

Belts tightened using arnnworx tensioning tool.

1. The new belt (conti) tracked towards the block and started wearing down the tensioner pulley flange. Created as much belt dust in 500km as the previous belt had done in its life time.

2. Checked the orientation and placement of all spacers and pulleys. Nothing strange there.

3. Suspected the new LASO water pump, as it had horrible bearing noises, and bought a second new LASO pump and stuck it on. This cured the grinding bearing noise but did not alter the tracking.

4. Dissasembled tensioner, cleaned it and inspected it for warping(eyballing). Installed a new pulley (the lip on the old one had worn thin).

4. Discovered slight damage to 3 of the teeth on the cam gear, someone must have slipped with a tool and nicked 3 teeth. Sanded the edges with emerald paper.

5. Installed new belt (gates). Spun engine several times by hand. Belt seemed to settle in the original position (on top of shiny wear marks on cam gear and centred on the tensioner pulley).

6. Started the car and the belt immediately crept towards the block and is now kept in place only by the lip on the tensioner pulley.

I refuse to believe that the crank or the camshaft can be out of alignement so i'ts got to be the tensioner or the water pump. I can't afford to buy a new tensioner just to check, so I'm posting here in the hope that someone recognizes the symptoms or can point me in the right direction.

I have invested a lot of time and effort into sorting out this problem and I DESPERATELY need it fixed so thanks a lot in advance for your help and suggestions.

bebbetufs

Comparison shots.

The roller to the left has done 500km. The one to the left was the one I removed when I got the car. I don't know how many km it has done.

In the side shot one can clearly see how the belt is rubbing against the lip of the roller wearing it thin. The original belt never even touched the lip. The same thing is happening now with the brand new roller currently installed.

St3mpy

Did you remove the crank at all? How's your oil pressure? Maybe you're missing one of the spacer washers?

xsboost90

im guessing this is the roller from the automatic tensioner? Are you sure its on faced the right way? Ive seen tensioners show up w/ the roller on backwards before. Even caused multiple belt failures....

bebbetufs

Thanks for your input.

The crank has been removed yes. End float is well within specs. Cam tower has been removed to change gasket. This problem showed up before that, however.

Tensioner roller has lip towards block, crank gear has lip away from block. There is a shiny spacer ring between the cam gear and the oil pump drive sleeve. I checked this morning with an inspection mirror just to be sure, even though I clearly remember installing it.

Could too much tension cause this? Maybe I'm using the Arnnworx tool incorrectly.

montel52

Please excuse my stupidity but what is the Arnnworx tool and why would you need it with an auto tensioner?

Mighty Shilling

Arnworx tools are awesome, and because the auto tensioner doesn't auto tension.

http://www.arnnworx.com/catalog/inde...index&cPath=65

BTW, WTF happened to the 920X? I love mine....

MacinTek

Best be sure the washer is installed, otherwise, the gear is too close to the block.
This would cause the belt to behave as you described.
Also, did you check the condition of the oil pump gear? I'd change that out if I'm takin' all that other stuff apart.

Van

Yeah, I vote that #14 is on backwards...

bebbetufs

Thanks, but please read before posting.
I've checked this several times, including yesterday with an inspection mirror as described in posts #1 item 2 and post #5.

The oil pump sleeve is new. I changed that when I swapped bottom end bearings and installed crank scrapers. I had the engine out of the car and also checked for wear. The crank is well within the "new part" tolerances.

apierce918

If you loosen the nut on the auto tensioner after 2,000 miles it does.

Mighty Shilling

Loosen then tighten? I just retension the damn thing every 10K. (and I'm due for it... next weekend)

mikey_audiogeek

uhhh... yeah, but there's a bit more to it than that. You have to rotate the crank to the right position first. I can't remember the procedue offhand, it has been posted previously. The method for rotating the crank is NOT the same as for cars without the auto tensioner.

Cheers,
Mike

Mighty Shilling

Do explain. I've been driving these cars since '02 and never heard of this procedure...

krazykarl

Looks like he designed a new tool that's simpler and cheaper. Good for everyone else but bad for me when I try and sell my tool =/