[Vwdiesel] Banana Rabbit--Bad news...

[James Hansen]

Well, if you get off with just changing the belt you'll have to change your
email to LuckyDavevw at yahoo.com  .
Personally, my line of attack would be to pull the cam, then turn the engine
over and see if one cylinder is leaking excessively, or if you hear a lot of
whooshing in the intake or exhaust when you rock the crank.  Another way
would be to use a leakdown tester, just let the piston bottom when you
pressure each piston up, watch for the turny bits as the piston goes to the
bottom. It's the surest way to check for valve collision damage.

But, the crank stuck with accompanying noise event at TDC screams foreign
object which could be solid or liquid.  Glow plug tip fall off? Oil build up
in the intake, then get slurped in?

...Insert brief interlude....
I got called away for a few hours, I like Loren's valve clearance checking,
but I do like checking for leakage, and it's an easy leakdown test when all
you're looking for is valves, and they are all closed, or supposed to be.
Turning it over with the glow plugs out is easy, and would be informative if
you can find a clunk.

I've stripped the cogs on a belt too.  Crank sprocket just eats them off
when the motor hiccups and it all starts to rattle, never had one go
kachunk, but it was uneventful. Quite the tense few hours until I had it
running again however.
-james

-----Original Message-----
From: vwdiesel-bounces at vwfans.com [mailto:vwdiesel-bounces at vwfans.com] On
Behalf Of Dave Cook
Sent: January-30-11 9:37 PM
To: VW Diesel Group
Subject: Re: [Vwdiesel] Banana Rabbit--Bad news...

Didn't think of stripped cogs.  Dangit!  The cheap car may have just turned
expensive!

To clarify, I wasn't turning the engine with the cam bolt, I used the
sprocket hold tool to attempt to turn the sprocket.  I didn't put much
pressure on it, I just wanted to see if it would turn backwards.  I figured
if a piston was touching a valve in one direction, it would be able to turn
backwards the other direction a little bit.  It did not but I may well have
been wrong in my assumption.

I think I will be optimistic and say that maybe since the engine wasn't
running at a super high rpm that I'll be lucky and it will just need a belt.


Lets assume I pull the belt and find that the cogs stripped.  I then pull
the valve cover and loosen the (intact) cam so all the valves close.  

If I am lucky and the engine can turn over loosly and freely, do you all
think I could get away with trying to retime the engine with a new belt and
see if it'll run?  Will there be obvious signs that a valve bent for sure to
look for?  (from above) If it runs, would you go ahead and drive it?  I
guess I'm saying, is there any way I might possibly get lucky and not have
to pull the head?

Interestingly, I noted that the TDC 0 is right at the center of the
inspection hole.  Actually, I suppose it isn't that crazy.  I guess that
means my likely candidates for bent valves would be cylinders 1 and 4,
right?  I did think it was nice that a past owner marked TDC with white
paint so it was easy to find.

Not sure when I'll get to look at it, it will probably be a few days.  I
usually work 4 long days then take Friday off though the impending crappy
weather might change that.

Dave Cook


--- On Mon, 1/31/11, LBaird119 at aol.com <LBaird119 at aol.com> wrote:

> From: LBaird119 at aol.com <LBaird119 at aol.com>
> Subject: Re: [Vwdiesel] Banana Rabbit--Bad news...
> To: vwdiesel at vwfans.com
> Date: Monday, January 31, 2011, 1:11 AM
>   I'm voting for an old belt
> stripped the cogs at the crank.  :-(  
> Pull the valve cover and release the valve spring tension
> (loosen cam 
> bearings) then try again to turn it over (first be sure
> you've tried 
> from the crank sprocket and see if the belt moves with ANY
> movement 
> of the crank).
>   Sounds like you might have broken the cam, bent
> valves, the usual 
> that happens with a slipped/broken timing belt.  Hope
> not but with 
> oil in it, it's unlikely it threw a rod unless you'd
> already heard it 
> hammering and seizing pistons don't tend to bang. 
> That just leaves 
> the cam and valves.
>      Loren
> _______________________________________________
> Vwdiesel mailing list
> Vwdiesel at vwfans.com
> http://www.audifans.com/mailman/listinfo/vwdiesel
> 


      
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