Date:         Tue, 7 Nov 1995 12:23:08 +0500
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         cetin@kirk.bellcore.com (Cetin Seren)
Subject:      EV Piston Slap

Dan Herbert writes:
 > Hi:
 > 
 > Could a more knowledgeable V@L member give
                ^^^^^^^^^^^^^
C'mon, those list members will only tackle real problems... You cannot
distract them from important activities like deciding which cupboard to
keep spark plugs in, weekly stats to invent, making friends with
junkyard dogs, etc., etc..... :-)

If you're willing to settle for the opinion of a lowly EV owner who's
been through this problem, here's my understanding:

It is essentially the case of the piston 'digging' itself a groove
inside the cylinder at the top of its travel.  I hear from other car
owners that the dealers who sell them brand new cars tell the owners
to mix city and highway driving well the first few thousand miles,
because highway driving tends to run the engine in one steady fashion,
which may cause the parts to wear-in in a fashion that will accentuate
any small irregularities in the piston/cylinder arrangement.  I guess
they figure if you drive in heavy traffic, there's plenty of
acceleration/deceleration, and the parts are worn in in a much more
random fashion, erasing the 'memory' of any systematic errors.

My '93 EV had this problem.  The symptom is that when you start the
engine in cold weather, when it's been sitting there for overnight,
you hear a clatter from the engine (very loud, much like a
Diesel) for about 20 seconds or so, then everything is normal.  

First the dealer did not accept anything was wrong with it, then I
asked them to give it to me in writing, stating that they have checked
the engine and it is sound.  This prompted them to take another look,
and order a new engine block for my EV.  They replaced it, everything
covered by warranty.  That was at 18,000 miles.  The EV now has 38,000
miles on it, the problem has not come back.

The trouble with this problem is that it is really pretty hard to
diagnose without taking the cylinder head off.  The mechanic, if an
experienced one, can tell the telltale sound with a stethoscope,
provided that the engine has been sitting overnight.

The implication is, as I understand it, shortened engine life....

Good luck with your EV....
Cetin

 > me a succinct explanation of the term
 > "piston slap"?  It has been mentioned
 > several times in connection with the 
 > 2.5 litre 5-cylinder, and I would like a
 > bit more info.
 > 
 > TIA
 > 
 > Dan Herbert
 > dan.herbert@utoronto.ca
 > 
 >