Run engine without AC/PS belts

[kgelles]

Can you run the engine with the front belt cover off (along with the power steering and ac belts) in order to inspect timing and balance belt operation? What are the clearances of the balance belt idler roller with the lower balance belt sprocket and the belt above it?

[Macfreak007]

yes, you can run the car with out the front cover, but I would caution you to take the back cover off as well, as this is what keeps the whole thing from rubbing the belts. Also the AC belt is the same one that drives the alternator so you would need to get a different size belt or something.

[Britwrench]

You won't see anything with the cover off and the engine running.
Either the belts need replacing or adjusting. Check the service history.

I usually run the engine for a few minutes after changing the timing belts to make sure everything is good, running with the alternator belt off for that short length of time doesn't make any difference.

[Porsche-O-Phile]

I've heard of someone slipping a greatly shortened belt over just the crank pulley & alternator to bypass the a/c compressor (IIRC it had a busted bracket or something) but it's a real PITA. I tried to do this on my 951 a while back since my a/c compressor clutch / pulley was bad and siezing up and snapping belts. Long story short, you can't really do it since the alternator doesn't have any "swivel" or adjustment capability - this is incorporated into the a/c compressor by means of the adjuster rod so if the compressor is the problem, you're hosed until you fix it.

Like I said, someone told me it COULD be done, but I'm sure it ain't easy since you're trying to stretch a belt over two more-or-less immovable pulleys. . .

[todwic]

I don't have p/s belts on either of my cars. I also have the front cover off on my '84, but I wouldn't recomend it. Though I think it would reduce the chances of a busted balance shaft belt wrapping around you cam belt, it also opens that precious belt to all the elements found inside of an engine compartment.

[kgelles]

Thanks. Idid manage to start the engine for a minute or so with the cover off and the power steering and alternoator belts off. The battery was able to run the engine for this period during which I was able to listen for any starnge noises coming from any pulleys or belts. Everything was fine and I put the cover back on and reinstalled all of the belts. By the way, in case anyone looks at this thread for the idler roller specs- I found out the balance belt idler roller should have 0.5mm clearance on the lower part of the roller and the belt underneath and should JUST touch the belt above. It should NOT interfere with the straigtline running of the belt above whetre it touches. Everything is running fine. Thank for the help.

[Britwrench]

Actually, the belt idler adjustment specification shows that it SHOULD alter the straight line of the belt.
The 0.5mm clearance on the lower run of the belt is correct.

[kgelles]

Thanks. Do you know the specifications of how much it should "push" into the belt?