Saturn overheating Installed new radiator, heater core, thermostat and fan module. It still runs hot.

This problem is caused by the coolant temperature sensor and this will cause you to think the car overheated but the gauge isn't working properly as supposed to

It would appear your thermostat is stuck in the closed position , find where it is on your engine, drain coolant and remove thermostat housing and stat, replace housing(liquid gasket OK) and coolant. now run engine, turn heater controls to hot leaving filler cap off, top up any water to max and replace cap now warm up to temp until fan comes on. if all ok replace thermostat with a new one and new gasket, you could also flush the sytem out at the same time with a hose pipe by loosening one of coolent pipes and flush radiator.

Is it ACTUALLY overheating? Check for heat at the top and bottom radiator hoses, and at both heater core hoses. If one is cold then your radiator or your heater core may be plugged and in need of a individual flush.

1.check coolant level---must open bleed valve above thermostat when adding coolant. 2. Are fans radiator fans running when car ovrheats & is air comming off of radiator hot? 3. Check/Replace thermostat. 4. There is a plastic elbow that connects from the intakke manifold to the engine block on the passenger side of car that arrre notorioous for cracking / leaking.... 5. The heater core on `05 Impala does not close when heater is turned off so does not benifit overheating by turning heater on.

disconnect the heat hoses going into fire wall , put hose into one with pressure and flush as it sounds like it could be bloked in the heater core,the other thing that could be the problem be the hot ,cold switch as it restricts the flow to makes the heater hoter or colder , it might need tlc or replacing as it is manaul not elec

Overheating can seriously damage a car's engine if left unchecked. Although overheating simply means that a car's engine temperature exceeds normal operating temperatures, the causes of overheating are varied. What follows is a brief list of some of the most common causes of engine overheating.

Faulty Radiator
1. A car that overheats will often have a faulty radiator. A radiator is responsible for cooling hot engine coolant that picks up heat from inside a car's running engine. A radiator "radiates" the heat from engine coolant out into the outside air. A faulty radiator loses its "radiating" effects and allows engine coolant to become overheated, thus rendering it ineffective at adequately cooling and engine.
Faulty Water Pump
2. A faulty or malfunctioning water pump prevents adequate engine coolant flow and can cause a car to overheat. A water pump serves to pressurize and propel engine coolant throughout a car's engine and radiator to increase the heat-reducing capabilities of engine coolant. A faulty water pump loses its ability to adequately pump and propel engine coolant, and can cause a car to overheat.
Coolant System Leaks
3. A leaky engine coolant system reduces the level of circulating engine coolant, which increases engine temperature and leads to engine overheating. Radiators, water pumps, and coolant system hoses and seals--all of these coolant system parts can develop leaks, which can result in low coolant levels and engine overheating.
Faulty Thermostat
4. A car thermostat regulates the flow of engine coolant. A thermostat is a heat-sensitive valve that opens when a car engine reaches a set operating temperature and closes when a car engine is cold and warming up. If a thermostat gets stuck in the closed position, coolant will be prevented from reaching the engine, which will quickly lead to engine overheating and potential engine damage.
Low Engine Oil Level
5. Engine oil, in addition to lubricating an engine's internal parts, helps to keep engine operating temperatures reduced by eliminating friction within the engine. If engine oil levels are low, friction and heat build up inside an engine, a condition that causes increased engine operating temperatures and can lead to engine overheating.

you either have a closed thermostat or a blockage in the radiator

i didn't see you last posting about your water pump but theres is a tiny radiator called a heater core. it has the same hot water running through it as your big radiator and engine have.so when you turn your thermostat to hot and kick on the fan the fan blows through the heater core and wallaa you have heat you probably need a thermostat.if you have no heat and it is overheating hear and there that's probably what you need.make sure you see if you filled the radiator up all the way when you changed the water pump.

The heater core being clogged would affect whether the interior gets hot air when set to hot temperature.

The heater core is like a very small radiator that wouldn't affect the temperature of the engine very much.

May I ask how hot it gets? Engines can get to 220 deg. F or 230 deg. F and still be considered to be running in a normal temperature range.

I posted this in a different web sight I hope it helps.


Re: Overheating and blowing cold air
I have been a mechanic for 20 years. Your problem is the heater core is plugged. The cold water from the radiator blows directly at the thermostat keeping it closed even when you are overheating! BAD DESIGN!! If you look at the water flow charts in AllData you will understand. If you rev the motor to 3,000 rpm's the turbulent HOT water at the water pump impeller (near the thermostat) will reach the thermostat to open it and the car's temp will fall very fast to the correct temperature. If you remove the thermostat it will not overheat but will run way to cold. If you bypass (loop) the heater core it will not over heat.

The hot water that leaves the heater core returns to the engine at the thermostat. It is the only hot water introduced to the thermostat to keep it open and allow the water to flow from and to the radiator. I normally just back wash the heater core and get large chunks of rust flake out then its fixed. Back wash then froward wash repeatedly many times. Also flush out the motor so you don't re plug the heater core. I hope you have now blown the head gaskets or cracked a head yet. Make sure to run the proper coolant in the car so you don't promote more rust flakes. And bleed the air out as mentioned in detail by other posters.

Nobody knows this little secret. Not even Subaru mechanics at the dealer, no TSB (Technical Service Bulletins a special note after the fact to mechanics). After days and days of trouble shooting a 1993 Subaru Impreza (2.0?) I looked at the water flow chart and then it was clear what was happening. This phantom overheating problem stumps the best mechanics and sends many Subarus to the crusher.

http://www.subaruoutback.org/forums/...threadid=17264