Why does the bypass line on the heating system have to be there?

The bypass is there to make sure your engine does not overheat in case the heater core plugs up. If you have flushed yours and are still not getting adequate heat, you may have a lot of large rusty particles jammed solidly in there

You don't say kitkatam but I have a feeling it is a 99

You don' t want heat all the time? goes thru the bypass-

On everything but the '99 Bob, it's as simple as what you said, it diverted the coolant when not in use .......but Ford got whacky that one year with the heater core hose routing

whoof- my goodness how embarrasing.

Or if your still not getting heat, you probably didn't burp the little bugger. LOL

'gmorning fellers

top 0' the mornin' to you too David and Gary. You know that you are my pals now and there's no goin' back now~

Could you guys hold it down, wow, looking over some of the past questions and man oh man, you guys are doing fine, but their is this guy that mentioned a coil that instantly got under my skin, first thing...oh well, need go check my attitude..and good morning to both of you also. Coffee time

Where is the Chrysler LEO? we have the Taurus, the Aries, abarth/fiat uses the scorpion think was it ford that had the Scorpio?

the Taurus is a not so good car. MOST have transmission troubles.

...think that's because most owners do not see the importance of using the Parking Brake, and not torturing the parking pawl. I have a friend with a taurus, try to explain this, am ripping my hair out for his lack of understanding.

None of these are valid answers: 1)Why would a plugged heater core cause an engine to overheat? Isn't that what the radiator is for? If that were true, then why do 99% of vehicles have one hose to the core from the water pump and one return to the intake manifold? ...And then there is the Taurus, with this funky pipe design??? 2)If you don't want heat all the time, that's what the blend door is for. The heater hose assembly bypass/heater core has no mechanical control on it, whatsoever. There is no "diverting". The hose assembly/core configuration is passive-delta in construction. 3)The Taurus cooling system is actively self-purging through the reservoir. There is no "burping" required, or even possible for that matter. 4)The claim that most Taurus have transmission problems, is highly subjective to numerous variables that could apply to any and all vehicles. On a long enough timeline, assuming no other powertrain or driveline component failure, the transmission of every vehicle ever manufactured will endure some sort of issue, malfunction, failure, etc., so it could be said that most cars in general have transmission problems. That being said, most Taurus I've driven, which number in the hundreds, have no make/model specific issues of transmission performance. The biggest recurring problem I've come across, is a failed torque converter shaft seal. I have noticed an increase in transmission issues with the Windstars, which theoretically is because ford uses the same basic powertrain to move a much heavier vehicle.