[Shotimes] Is engine OK? was: SHO cranking but not starting

[Bill Murray]

If you have a 1/2' of play in the timing belt, I would think it would
almost be a guarantee that the belt jumped a few teeth.  The marks on
the pulley should line up with marks on the belt when it was new, along
with the 2 divots in the timing gears that line up with hash marks on
the rear timing cover.  Take everything apart, realign the gears, reseat
the belt and make sure then tensioner is tight.  That's my guess.

Bill Murray

> -----Original Message-----
> From: Koper Jim [mailto:jkoper@frankgates.com] 
> Sent: Tuesday, March 16, 2004 12:45 PM
> To: stevwein@swbell.net; shotimes@autox.team.net
> Subject: [Shotimes] Is engine OK? was: SHO cranking but not starting
> 
> 
> Steve,
> 
> 92 MTX.
> 
> It thought it might be too much slack (especially at the top 
> like that), but
> the belt was replaced summer of '02, about 10-12K miles ago 
> along with the
> water pump, crank position sensor, cam position sensor, 
> shims, plugs, wires.
> I wonder if the belt tensioner has come loose. Probably can't 
> adjust it
> through the little window on the middle(?) cover. I'd bet 
> that I have to
> tear apart the front of the engine to really adjust it.
> 
> A belt jumping a tooth is a somewhat rare occurrence?  Have 
> you noticed that
> there are, IIRC, TWO 'white' marks and one 'yellow' mark on the crank
> dampener?  Which white mark do you actually use? Helms does 
> not specify, and
> perhaps that is where the problem started. I had a good 
> amount of guidance
> (by phone and e-mail!) with George Fourchy that summer, so I 
> figured I did
> it correctly. Maybe not! Perhaps the slack started IF I used 
> the wrong white
> mark....
> 
> I didn't pull the cover completely off--just enough to see if 
> the belt was
> still rotating or if it had broken.
> 
> Dampener pulley was loctited and torque to 115 lb-ft, per 
> Helms. I wondered
> if I should have added a little more to that number. What 
> torque spec have
> you used?
> 
> Thanks for your contributions!
> 
> Jim
> 
> 
> 
> <your message below>
> 
> Several issues come to mind.
> 
> Too much timing belt slack.  How old is it?  ATX or MTX?  
> Might just be a
> stretched belt that has jumped time - check static belt 
> alignment.  If ATX,
> might be the tensioner has lost pressure.
> 
> The noise is likely to be either rod bearings, cam 
> chains/tensioner, or
> crank cancer.  Was there a good dusting of reddish powder 
> inside the timing
> belt covers?  This is a strong (but not the only) indicator 
> of crank cancer.
> A mechanic's stethoscope is a valuable tool for isolating the 
> source of the
> knock/noise.  About $10 Unless you have a harbor Freight 
> nearby, then $2.50
> on one of their sales).
> 
> Do check the IAB.  It is likely the source of your idle 
> problems.  Look for
> other vacuum leaks before jumping into replacing it.
> 
> Steve
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