RE: help--overheated 86CGT

[Ed Kellock <EKELLOCK@ecs-inc.com>]

The problem was really quite simple...

The cap was replaced incorrectly, allowing fluid to escape when it got
hot, causing steam, etc.  Then when the car was allowed to cool for 30
mins and restarted, the coolant level was too low, and the digital
dash's temp gauge did what it was designed to do to tell you to check
coolant level.  It flashes the full hot reading.  Check the owner's
manual to verify that this is the proper function.

> -----Original Message-----
> From:	Ken [SMTP:kkeith@qnet.com]
> Sent:	Monday, January 26, 1998 6:21 PM
> To:	quattro@coimbra.ans.net
> Cc:	jblancha@u.arizona.edu
> Subject:	re: help--overheated 86CGT
> 
> Jeffrey A Blanchard <jblancha@u.arizona.edu> wrote:
> > 
> > My 1986 Coupe GT overheated on the way to the university this
> morning.
> > I opened the hood and noticed coolant was coming out from the
> expansion
> > tank but didn't seem especially hot.  The temp gage was in the
> normal
> > range.  After sitting there for 30min, I started it up and the temp.
> gage
> > immediately read "HOT", but no rad. fan.  I shorted out the radiator
> fan
> > thermoswitch and the radiator fan came on but didn't seem to have
> much of
> > an effect on the temperature (I didn't leave the engine running long
> since
> > it was so hot).
> 
> Sounds strange.  I know engines are supposed to "get hotter" after
> sitting, 
> as the heat soaks into the engine from the coolant.  That might be
> what 
> happened here, but that doesn't explain the overflowing coolant.
> 
> I suspect that if there is steam, the motor is either actually
> overheated 
> and hot enough to overcome the caps overpressure relief valve, or the 
> cap is bad and needs to be replaced.  Is the reservoir cap black or
> white?
>  
> > Is it possible that the water pump is bad?  It is on the timing
> belt, so
> > it must still be turning.
> 
> A problem I've heard of with the waterpumps is that the impeller will 
> actually *slip* on the shaft.  So, everything is turning except the
> part 
> that really needs to be.  That might be a possible cause.
> 
> Also, I think on the '86 Coupe GT's, you should have an "after-run"
> fan 
> switch, which should cause your radiator fan to come on when the
> ignition 
> is switched off if the head is hot enough.  If that's not happening
> (and 
> your car actually has this feature, earlier one's didn't) then you
> might 
> have a problem with the fan and/or it's electrical circuit.
> 
> > I will short out the rad. fan thermoswitch
> > after it cools down and try idling it and see what happens.
> > 
> > BTW, Yesterday I was working on the car but only changed the oil,
> > tranmission oil, and spark plugs.  
> 
> I wish it was that easy for me.  I still have a "plugged" tranny, and 
> can't get the plug out.
> 
> Just kinda throwing it out there, HTH.
> 
> Good luck,
> 
> Ken