I have a 1999 Ford Taurus that would not heat, took to shop they flushed the system, replaced the water pump and it ran hot after thet flushed the system took it back they flushed the system again and

unless it is the heater core which you should flush system,,i always boil my new thermostat to make sur it compresses

Either the water pump not working,,or you have a clogg some where..I have seen the impellor break on the water pump..The outside pulley was turning but the inside wasnt..

what was the worst about the pump?I don't know what that means? the no heat could be a clogged core, try to flush it in both directions and make sure water flows freely. As for the rough idle... is the car overheating or pushing out coolant? if so there could be head gasket issues?>?

Sounds like the problem has to be the valve is not opening and thus not allowing the hot coolant to enter the heater coil. Manualy open the valve (engine firewall) and see if heat is present. If this works check your cable from the dash switch as it isn't working the valve properly and needs replacing.

check coolant to ensure you dont need a flush also replace the thermostat.

These Tauruses had a problem with the heater cores plugging up, blowing out the head gaskets and no heat issues. Ford issued a TSB#98B26 (Tech Service Bulletin) to modify water pump and install a heater hose bypass tube. I would start by completely flushing the system with a good flush. Then reverse flushing the heater core. Refill the system and add a good additive. Also you can install the heater bypass tube as described in the TSB. The last one I did ran around $90 and 2 hours labor. Hope this helps you out.......

replace your water pump. i had the same problem last week. the impeller was rusted away. now it heats really well. the pump isn't hard to replace at all. when you buy your new pump, draw around the pump on a piece of card board marking all your holes. when removing your old pump, remove the bolt and stick it in the pattern. now you will know where each bolt goes back. good luck, brotha bill

Those cars were also notorious for the turbines rusting off the back of the water pump causing poor water flow. When the car has been running check the upper and lower hoses to make sure the are both warm. If the cooling system was in very poor condition before this work you may also have a plugged up radiator. Keep track of your coolant level for blown head gasket. Also check your oil regularly for milky color. This is a sign of coolant getting in to oil.

Hi,

You haven't said what is actually wrong with the heat system (there can be several different failures). For the time being I'll assume the fan blows plenty of air but the air is always cool/cold regardless of where the heat temperature selector is positioned.

The most common cause on these cars is a plugged heater core. With the engine at normal operating temperature, feel the heater core hoses (under-hood, mid/lower portion of firewall, access from passengers side). They should both be very warm. If not expect blockage in the heater core.

While a replacement heater core along with a good cooling system flush is the ultimate cure, reverse flushing the heater core will restore heat. This can be accomplished with a garden hose. Disconnect both heater core hoses (not with the engine hot as the coolant get very hot!!) and connect a garden hose. Turn on the water supply to flush the core. Flush the core in both directions (by hooking the hose to one side of the heater core and letting the water run, then disconnecting and connecting to other side of the heater core...). An old garden hose with end cut will work fine if your existing hose will not fit over the pipe (plumb it together anyway you can).

The heater core sits rather low in the cooling system. This means crud in the system will settle there eventually causing blockage. If you flush the core the crud will eventually cause blockage again. Reflushing will work over and over again if saving money is the primary goal.

If this is not the problem, the blend air door is probably not working.

Reply and we'll continue. I don't want to repeat things that have already been done, as $2000 should of covered both things I have mentioned.

I had the same problem on my '99 Taurus and got it fixed today. I had the heater core back flushed. The water was just filthy. I haven't had heat in my car for a couple of years like I have now. My mechanic recommended that I come back in a week and have it flushed again.