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

Dave Cook davevw at yahoo.com
Mon Jan 31 09:20:17 PST 2011 

Since the wonderful ice and snow storm has moved into the area, I have less to do with work.  So that means that I can spend some time with the car this evening.  We shall see what happens.

So, lets presume that there are a couple bent valves.

Can I just order some valves and seals and replace them?  Will I need any special tools?  Is this something I can do without having to rely on a machine shop-assuming there aren't any signs of warpage?  (The only one in town screwed up a part for me a couple years ago and still charged me for it.)

Dave Cook


--- On Mon, 1/31/11, Val Christian <val at mongo.mongobird.com> wrote:

> From: Val Christian <val at mongo.mongobird.com>
> Subject: Re: [Vwdiesel] Banana Rabbit--Bad news...
> To: vwdiesel at vwfans.com
> Date: Monday, January 31, 2011, 2:19 PM
> I had an 84 Rabbit which slipped the
> cam sprocket.  I was getting off the 
> expressway, and just pulling out of the stop sign.  No
> thunk, no noise,
> except the other vehicles honking at me to get out of their
> way.
> 
> Farmer friend was done with the girls for the afternoon, so
> he came and towed
> me home.  I found that there was some movement of the
> crank, but there was
> definitely interference.  So I pulled the head that
> evening.  Two bent
> valves, and one somewhat dinged piston, the other just
> nicked.
> 
> I replaced the valves, and all the valve seals etc while I
> was at it.
> Put it back together and continued to run it for years.
> 
> I have seen a VW diesel, where the valve broke, and
> embedded itself into 
> BOTH the piston and the head.  I didn't get the full
> story on the 
> symptoms, but it sort of fits your description.
> 
> Either way, they are normally fixable.  We'll all wait
> to see what 
> you find.
> 
> 
> 
> > 
> > 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
> > > =A0 I'm voting for an old belt
> > > stripped the cogs at the crank.=A0 :-(=A0 =
> > 
> > > 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).
> > > =A0 Sounds like you might have broken the cam,
> bent
> > > valves, the usual =
> > 
> > > that happens with a slipped/broken timing
> belt.=A0 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.=A0
> > > That just leaves =
> > 
> > > the cam and valves.
> > > =A0 =A0=A0=A0Loren
> > > _______________________________________________
> > > Vwdiesel mailing list
> > > Vwdiesel at vwfans.com
> > > http://www.audifans.com/mailman/listinfo/vwdiesel
> > > =
> > 
> > 
> > 
> >       =
> > 
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