is my engine shot!?

Question

i was working on my bug and out of habit gave a tug to the fan belt pulley (the lower one connected to the crankshaft) and it moved in and out, maybe .5mm and with a thump when i moved it forward.

problem is the motor is only two years old, and i can't believe it could possible have cocked up already.

there is no oil leak at all, and i know the last time my big end bearing had gone (the reason i got this recon in the first place) my car was leaving its mark everywhere. there is also no shudder on the clutch which would be a clue that there's a small leak on the flywheel side right?

anyway, what i want you to tell me, is that its still early enough to see to it, pull motor and reshim the flywheel? it is bloody awful that it should happen now! or even that this is of no concern whasoever.

any advice?

Speedy Jim · Accepted Answer

The engine is cocked up.

0.5mm = .020"

The wear limit is 0.15mm = .006"

More than likely you will *not* be able to shim the flywheel.

What usually happens is that the front main crank bearing spins in the case. That wears the bearing material down AND wears the case down. So, the bearing can now float back and forth in the case, which is why the pulley moved easily in and out.

If you were very, very lucky and all the wear occurred in the bearing, you might be able to replace it (after complete teardown). But chances are that the case would need to be bored/thrust-cut for over-size bearings.

I'm giving you the least cheerful scenario because that has been my experience.

It will live a while longer. Eventually the play will be so great that the front seal won't seal and there will be a *big* oil leak.

Cheers,

Speedy Jim

formatting link

veeduber · Answer

------------------------------------------------

Screws up your timing, too. The distributor's driver gear is driven by the brass scroll gear on the crankshaft. Axial motion not only promotes accelerated wear in the scroll gear, the motion itself acts to advance or retard the firing point, according to which way the thing moves. Worse case, at idle the engine is liable to stumble & die when you depress the clutch. Vast mystery, of course :-)

(Doesn't do the cam gear any good either, but there the 2:1 ratio is

50:25, whereas the scroll gear is 12:6.)

-Bob Hoover

Lorem Ipsum · Answer

Are you sure the pulley isn't simply pulling off the shaft?

is my engine shot!?

Join the Discussion

Didn't find your answer?