[Supras] Auto Trans & Oxygen Sensor Questions

[Christian, Skip]

Studioartist,

	I wish 300K was possible with the original head gasket.  Mine
went at around 120K.  When I replaced it, I noticed the block deck was
trashed.  Head gasket must have been leaking for at least 30K miles
before it let go.  I had only spent $1500 for the car & hadn't planned
on rebuilding the engine (other than the head gasket car ran fine and
looked good).  So I just stuck on a new head gasket and crossed my
fingers.  Two weeks later, I started hearing the famous gurgling sound
from the dash (heater core) telling me that the new gasket had started
leaking.  Needless to say, I was pissed......  So, I got out the torque
wrench, and torqued all the head bolts (in sequence) to 85 ft-lbs.  What
did I have to loose ?  The "trenches" in the block deck looked like they
were deeper than the allowable milling limit.  Anyway, its now been
about 100K miles on the same head gasket.  As long as I let the car
fully warm up (temp gauge needle about half way up) before I touch the
throttle, it uses no coolant !!!  Power is still reasonably good.  If I
remember correctly, the gasket is blown on #3 and #4 cylinders.
	Now, if I can just get the auto trans to stop shifting from
first straight to fourth.......
	Really would like to know if anyone has made it to 300K miles
without rebuilding the engine bottom end.  Trans internals should last
this long if fluid is changed.  Since all 7Ms blow head gaskets, there
probably isn't a 7M Supra around that hasn't had a valve job.  When I
had my head off, I had two valves ground, and all the stem seals
replaced.  The new stem seals at 120K changed the oil consumption from 1
qt every 700 miles to 1 qt every 2500 miles.

Thanks, Skip
'86 MA70


---------------------------------------------------------------
Original Message
Date: Tue, 13 May 2008 19:43:26 -0700 (PDT)
From: LN <studioartist at yahoo.com>
Subject: Re: [Supras] Supras Digest, Vol 53, Issue 16
To: supras at supras.com
Message-ID: <489860.95412.qm at web30406.mail.mud.yahoo.com>
Content-Type: text/plain; charset=us-ascii

If you can get 300k miles on stock head gasket it would be a first.
Mine went to 135k then it was gone.  Hope that answers it.