i just changed my water pump because the kid who i had bought the car off of said it was going bad. after i changed it and added plenty of coolant the light kept going on and off & i filled when letting the heat run & it stills comes on. so i changed the thermistat and tried to tighten the drive belt & it still comes on and off. does any one have a clue what it could be? coolant sytem need to be flushed? new belt?

 

and the car isnt getting hot because the temp guage is stayin below halfway unless its broken.

 

FCs commonly have a problem with the "add coolant" light - the sensor is at the top of the rad - inspect the wiring.

i know a few FC guys who have an excellent cooling system, but they still have that light problem.

 

Did you flush the radiator when you changed the pump? If not you probably have a nice big air bubble in your coolant. And everytime the buble sweeps past the sensor it thinks that you have no coolant. Try taking the car around the block and taking a nice big hard left turn if it turns off around the turn you probably have an air bubble.

 

S4's have an air bleed plug on the side of the radiator's top hose connection. This must be open during filling to bleed air flom the system as you fill it. The radiator cap should be left on during filling, and coolant poured in through the filler cap on top of the thermostat housing. Once coolant overflows from the bleeder plug, screw it back in and finish filling the system. With the filler cap still off, start and run the engine (with the heater on) until no more air bubbles are visable, then refit the filler cap. This method will ensure no air bubbles and hopefully no warning lights.

 

yup. Since I'm tracking down a cooling problem I'm doing this a lot.

I would pop the radiator cap off alittle bit so it can push air a little bit.Then take off the fill cap(assuming your coolant is below the rad cap level,lol).

I pour into the fill hole and wait until i see coolant start to trickle out the rad cap. Then just tighten it quick and top off the system.

I usually put the cap back on and run the car for a minute with the heater on full,then do this again to ensure it's all out.

 

did you change your thermostat too?

 

How do you bleed with a Fluidyne radiator? It has a cap instead of the air bleed screws. So I have the cap on the radiator and the one on the waterpump neck with hoses coming off both to a tee to the overflow tank and I've got the bubble problem but is must be a small bubble since it doesn't happen all the time.