20v Cap and rotor Q&A
b.benz at charter.net
Tue Jan 14 16:01:22 EST 2003
Steven Hauptmann <hauptmanns at MAIL.LLR.STATE.SC.US> wrote:
> 1.)Ignition timing.
> It sounds like the plastic distributor gear (which drives off of the end of
> the intake cam) is broken, hence the rotor turning freely. Although it's
> conceivable, I doubt that these small plastic gear pieces did any damage. It
> is way out on the end of the cam, and the pieces have likely just fallen
> down and will be easily removed when you remove the distributor. If it were
> mine I'd remove the cam cover and have a look see. This would make vacuuming
> the broken pieces a little easier as well. Assuming these pieces are all
> accounted for, this will not cause engine damage. The distributor is simply
> no longer spinning with the camshaft, distributing spark to cylinders.
If the dist rotor can be rotated through any angle, one knows that the gear
is minus at least one tooth. If not, and inasmuch as the engine has to be
advanced to #1 TDC to check the timing anyway, one can check the rotor for
rotation with the crank and its alignment mark to the crank. If OK, no need
to go to the TB, unless the same monkey did that job.
Assuming a broken gear, and that the loose piece(s) did not catch under a
cam lobe at the time of break, I would have no concern about pieces
remaining in the engine. IMO, they will almost immediately be washed into
the pan or find a valve area cranny in which to lodge.
> 2.)The valve timing.
> Of course when the camshaft is no longer timed to the crankshaft, valves get
> bent when the pistons hit them. This is where the possibility of large
> expense will be.
> First order of business is to have the mechanic check and see if your cams
> are still aligned with the crank.
> The front grill and bumper as well as the intercooler, p/s belt and t-belt
> cover should be removed.
> Then the mechanic can turn the crank over and attempt to line up the crank
> and cam timing marks.
> If they line up and the flywheel is at TDC, then I would suspect all you
> need is a new distributor. If the t-belt happens to be loose, teeth missing
> etc., then you will want to have a new one installed while he is that far
> into it.
> If the crank and cam timing marks do not line up, then the head would need
> to be removed to replace the bent valves and inspect for other damage, in
> addition to the distributor replacement.
> The mechanic should know if your valve timing is out BEFORE he tells you if
> the head needs to be removed.
> Don't give up, it's worth repairing.
> Good luck,
> Steve Hauptmann
> South Carolina
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