I have had very low or no heater/defroster hot air output on my 97 Taurus GL
wagon (3.0 liter Vulcan with AC) since I used some Prestone Stop Leak to
(successfully) control a slow loss of coolant level. I suspect the coolant
loss was a due to very small head gasket leak, as there was no evidence of
external leakage at the ususal suspect locations, and no smell of leaking
coolant anywhere inside or outside of the car.

Back to the heater, since the Stop Leak was introduced, heat output has been
very low or non existent, though very infrequently, I do get some hot air
out. The engine and the rest of the cooling system is coming to normal
temperature, however, the return line on the heater is cool, indiciating to
me that the core is likely clogged, probably from the Stop Leak. The heater
bypass hose is hot, so it looks like everything else is OK.

I am going to try to backflush the heater core through its supply and return
hoses. Is this likely to clear the clogging? Assuming that it does not,
how difficult is it to actually change out the core? I've done this on a
few other cars, and it usually requires a massive dashboard disassembly.
Never done this on a car with dual air bags.

Am I overlooking something obvious, such as a stuck thermostat? I'm
thinking that's OK, based on otherwise normal coolant temperature gauge
readings, and the fact that flow in the bypass line, which appears to be
directly in parallel with the heater core, is hot.

Look below for a thread "99 Taurus heater problems". I flushed mine, and
it has helped. I disconnected the heater core hoses, and flushed it
seperately with scalding hot water from a garden hose connected to the
water heater in my barn, and it helped a lot. From what my Haynes manual
has on changing the heater core in a Taurus, its not a fun nor easy job.
If you have the orange Dex-Cool antifreeze, get rid of it. It had turned
to sludge in my Taurus, causing the heater core blockage.

Flushed with success!

Thanks for the info J! I backflushed the heater, first with about 20 psi
air from my compressor, and then with flow from a garden hose for about 10
minutes. Hooking things back up, I was immediately rewarded with copious
waves of HOT air from the system, like I've never had since new. I'll bet
that I was losing heater flow long before the Stop Leak shut things down
even further!

Details for other 96-97 vintage Taurus owners:

Make sure you BACK-flush (i.e have the flushing flow go in reverse of normal
to break crud loose, rather than drive it in further with a forward flush)
as described below. Your system has been trying to forward flush without
success for as long as you have had your problem!

I disconnected the heater by removing the short hose going from the hard
pipe on the right side of the firewall (normal return to y-pipe) at water
pump suction, and by disconnecting the short hose from the other "y-pipe" at
the left side of the firewall at the supply end. (The y pipes provide the
connection points for the heater bypass hose. I think the y-pipes and the
bypass hose were part of a recall mod made shortly after I bought the car.)

Hooked up a short garden hose section with the female end connector to the
heater return side hard pipe on the right fireall. Positioned the short
section of hose still connected to the heater supply end hard pipe on the
left side of the firewall so it's discharge when back-flushing wouldnt get
into the transmssion fluid dipstick pipe.

Made up an adapter with a short section of garden hose with the male
connector to connect up my air line to the garden hose section on the heater
return pipe. Set the compressor regulator to about 20 psi to prevent
overpressurizing the heater core in case it was REALLY clogged up.

Blowing down with air blew out a big slug of nasty looking stuff and rusty
coolant. After a few minutes of air purge, switched over to a water purge
for about five minutes, using a local ball valve to throttle the water
supply to keep the pressure down. Water discharging was clear throughout
the flush.

Removed the backflush adapter, restored the hose connections with new
stainless hose clamps, and topped off the expansion tank (since I was
working on high points of the system, I didn't fully drain the whole system
beforehand, and only lost a small amount of coolant when initially breaking
the connections).

As soon as the system warmed up after starting the engine, WOW! Heat
blasting from the vents! SUCCESS! Unbelieveable what a small amount of
crud it takes to foul a heater core.

Wonder what the local Ford Dealer would have raped me for to correct this?
Probably would have tried to sell me a new core and the associated major
labor to tear the dash apart. Here's hoping that the core doesn't develop
leaks....




"J Grant" <snuffy2220 (AT) webtv (DOT) net> wrote

I'm beginning to think that this is a common problem with Tarurses. A
lady I work with has a 99 Sable with the same problem. Does your 97 have
the orange antifreeze? If so, its only a matter of time before its
clogged again. Flush the entire system really well, then switch her to
green!

It originally had the Ford orange stuff. I think the dealer changed it to
green when they did the "rust in coolant" recall that added the bypass line
about a year after I bought the car. I had the coolant replaced about a
year ago, just after I had added the Stop Leak. The oil change shop that
claimed and charged big time for a "flush" of the system nothing more than
a drain and refill. That change did not fix the low heat output problem.
And they re-filled the expansion tank solid, which caused a big mess when
the fill cap relief valve lifted on the way home as a result. Luckily,
nothing worse happened. I have been living with the lack of heat through
the warm weather, but driving through the season's first snow storm the
other night with a windshield that was constantly fogging up due to the lack
of heat finally got me motivated to fix it right!

"J Grant" <snuffy2220 (AT) webtv (DOT) net> wrote

Dont'cha just love happy endings!!!!!


Chris Bowne opined in news:10pgkib4hvlu1e6 (AT) corp (DOT) supernews.com:

Chris, I owe you a 6 pack for posting your procedure. I just followed it,
minus the air compressor portion, and I have heat again in my 98 Taurus.
What kinda beer do you drink?

Chris, I owe you a 6 pack for posting your detailed procedure. I followed
it, minus the air compressor portion, and I now have heat again in my 98
Taurus. What kind of beer do you drink?

Is that 12 beers total ????????


"walshb" <bjw59 (AT) hotmail (DOT) com> wrote

All my posts show up......eventually.

It's 12 beers only if Chris requests them.