So My car is getting hot day or night, it won't go above 240 degrees or so, but is running 220 at night and 230-240 during the day. I did just recently clean/oil my blackwing filter and reinstall it, but that's about it. Nothing appears to be blocking the radiator and my coolant tank shows no leakage although I can't see the fill line on the tank. Any ideas?? Could I of wrongly reinstalled the air filter, maf, etc??....

 

Give us some conditions.
Is this a new thing?
Outside temperature?
Speeds?
AC on or off?
Is the car tuned or stock?
Did you check the fans?

You could easily see those conditions when stock at slower speeds. But it should get down to below 210* cruising at higher speeds, say easy driving at >30mph.

 

I agree with checking the fans and also check the radiator and ac condenser for dirt/debris stuck in between the fins... this will prevent air from flowing past the core which you don't want... they make a tool that uses either air or water to blow the stuff out without having to completely remove your radiator/condenser

 

It's a new thing. Doesn't matter A/C on or not. Starts getting hot as soon as I drive it whether 65 degrees out or 90. The car is a tuned 416 stroker. How do I check the fans? I assume they are working cause in stop and go traffic it reached 241, but then would cool a bit, but always staying between 225-240. I can drive 5 miles after a cold start and the car is already reaching 220 or so... Normally I think my temps are between 190 and 220 or so...

 

The only other thing was the car was smogged(wink wink) but I didn't see them do it.

 

There is no prob with blockage to the radiator that I can see, and I assume the fans are working because it doesn't get 245+ or to the point of overheating. At 240 temp will go down a bit. Just seems kind of all a sudden...

 

As it gets hot the fans should first come on low speed and then high speed. If you can't see them turning then stick the end of a tie wrap into the fan to see if the blades are moving. Since it's modified, I could only guess at what temperature the fans come on.

 

TAKE your Radiator OUT and CLEAN it...clean the A/C Condenser while your at it... NOT hard to take out the Radiator... Put in a 160 degree stat and make sure there is NO air in the system when you put it back together... it doesn't matter how clean your radiator LOOKS.. it can still be plugged/blocked with crap that is like little bricks between the fins...dust, cottonwood fiber, seeds, a little moisture and it blocks/packs the fins OFF.... and you CAN'T blow it out... I tried.................
TAKE it out and CLEAN it...................................... ..............

Make sure fans are working like stated in previous post and NEW coolant reservoir cap may help too...

 

Sounds good guys! I'll do a thourough cleaning and make sure the fan are both turning on an go from there. I'll check back once I know the results.

 

Here is an overview of HOW your coolant system operates... may help with understanding what problems can arise.

Cooling System Description and Operation

Cooling Fan Control

The engine cooling fan system consists of two electrical cooling fans and three fan relays. The relays are arranged in a series/parallel configuration that allows the powertrain control module (PCM) to operate both fans together at low or high speeds. The cooling fans and fan relays receive battery positive voltage and ignition 1 voltage from the underhood electrical center. The ground path is provided at G102.

During low speed operation, the PCM supplies the ground path for the low speed fan relay through the low speed cooling fan relay control circuit. This energizes the cooling fan 1 relay coil, closes the relay contacts, and supplies battery positive voltage through the cooling fan motor supply voltage circuit to the left cooling fan. The ground path for the left cooling fan is through the cooling fan 3 relay and the right cooling fan. The result is a series circuit with both fans running at low speed.

During high speed operation the PCM supplies the ground path for the cooling fan 1 relay through the low speed cooling fan relay control circuit. After a 3-second delay, the PCM supplies a ground path for the cooling fan 2 relay and the cooling fan 3 relay through the high speed cooling fan relay control circuit. This energizes the cooling fan 3 relay coil, closes the relay contacts, and provides a ground path for the left cooling fan. At the same time the cooling fan 2 relay coil is energized closing the relay contacts and provides battery positive voltage on the cooling fan motor supply voltage circuit to the right cooling fan. During high speed fan operation, both engine cooling fans have there own ground path. The result is a parallel circuit with both fans running at high speed.

The low speed cooling fan is commanded on when the coolant temperature reaches 108°C (226°F). It is turned off if the coolant temperature lowers to 104°C (219°F). The high speed cooling fan is commanded on when the coolant temperature reaches 113°C (235°F). It is turned off if the coolant temperature lowers to 108°C (226°F). When the A/C is on and the coolant temperature reaches 85°C (185°F), the low speed cooling fan will be turned on at vehicle speeds less than 56 kPh (35 mph).



Engine Coolant Indicator(s)

COOLANT OVER TEMP

The IPC illuminates the COOLANT OVER TEMP indicator in the message center when the following occurs:

The PCM detects that the engine coolant temperature exceeds 124°C (256°F). The IPC receives a class 2 message from the PCM indicating the high coolant temperature.
The IPC will also illuminate the CHECK GAGES indicator and a chime sounds when this condition exists.
Cooling System
The cooling system's function is to maintain an efficient engine operating temperature during all engine speeds and operating conditions. The cooling system is designed to remove approximately one-third of the heat produced by the burning of the air-fuel mixture. When the engine is cold, the system cools slowly or not at all. This allows the engine to warm quickly.



Cooling Cycle

Coolant is drawn from the radiator outlet and into the water pump inlet by the water pump. Some coolant will then be pumped from the water pump, to the heater core, then back to the water pump. This provides the passenger compartment with heat and defrost.

Coolant is also pumped through the water pump outlet and into the engine block. In the engine block, the coolant circulates through the water jackets surrounding the cylinders where it absorbs heat.

The coolant is then forced through the cylinder head gasket openings and into the cylinder heads. In the cylinder heads, the coolant flows through the water jackets surrounding the combustion chambers and valve seats, where it absorbs additional heat.

Coolant is also directed to the throttle body. There it circulates through passages in the casting. During initial start up, the coolant assists in warming the throttle body. During normal operating temperatures, the coolant assists in keeping the throttle body cool.

From the cylinder heads, the coolant is then forced to the thermostat. The flow of coolant will either be stopped at the thermostat until the engine is warmed, or it will flow through the thermostat and into the radiator where it is cooled and the coolant cycle is completed.

Operation of the cooling system requires proper functioning of all cooling system components. The cooling system consists of the following components:



Coolant

The engine coolant is a solution made up of a 50-50 mixture of DEX-COOL and clean drinkable water. The coolant solution carries excess heat away from the engine to the radiator, where the heat is dissipated to the atmosphere.



Radiator

The radiator is a heat exchanger. It consists of a core and two tanks. The aluminum core is a crossflow tube and fin design. This is a series of tubes that extend side to side from the inlet tank to the outlet tank. Fins are placed around the outside of the tubes to improve heat transfer from the coolant to the atmosphere. The inlet and outlet tanks are molded with a high temperature, nylon reinforced plastic. A high temperature rubber gasket seals the tank flange edge. The tanks are clamped to the core with clinch tabs. The tabs are part of the aluminum header at each end of the core. The radiator also has a drain **** which is located in the bottom of the left hand tank. The drain **** includes the drain **** and drain **** seal.

The radiator removes heat from the coolant passing through it. The fins on the core absorb heat from the coolant passing through the tubes. As air passes between the fins, it absorbs heat and cools the coolant.

During vehicle use, the coolant heats and expands. The coolant that is displaced by this expansion flows into the surge tank. As the coolant circulates, air is allowed to exit. This is an advantage to the cooling system. Coolant without bubbles absorbs heat much better than coolant with bubbles.



Pressure Cap

The pressure cap is a cap that seals and pressurizes the cooling system. It contains a blow off or pressure valve and a vacuum or atmospheric valve. The pressure valve is held against its seat by a spring of predetermined strength, which protects the radiator by relieving pressure if it exceeds 15 psi. The vacuum valve is held against its seat by a spring, which permits opening of the valve to relieve vacuum created in the cooling system as it cools off. The vacuum, if not relieved, might cause the radiator to collapse.

The pressure cap allows pressure in the cooling system to build up. As the pressure builds, the boiling point of the coolant goes up as well. Therefore, the coolant can be safely run at a temperature much higher than the boiling point of the coolant at atmospheric pressure. The hotter the coolant is, the faster the heat moves from the radiator to the cooler, passing air. The pressure in the cooling system can get too high, however. When the pressure exceeds the strength of the spring, it raises the pressure valve so that the excess pressure can escape. As the engine cools down, the temperature of the coolant drops and a vacuum is created in the cooling system. This vacuum causes the vacuum valve to open, allowing outside air into the cooling system. This equalizes the pressure in the cooling system with atmospheric pressure, preventing the radiator from collapsing.



Surge Tank

The surge tank is a plastic tank with a pressure cap mounted to it. The tank is mounted at a point higher than all other coolant passages. The surge tank provides an air space in the cooling system. The air space allows the coolant to expand and contract. The surge tank also provides a coolant fill point and a central air bleed location.

During vehicle use, the coolant heats and expands. The coolant that is displaced by this expansion flows into the surge tank. As the coolant circulates, air is allowed to exit. This is an advantage to the cooling system. Coolant without bubbles absorbs heat much better than coolant with bubbles.



Air Baffles and Seals

The cooling system uses deflectors, air baffles and air seals to increase system cooling. Deflectors are installed under the vehicle to redirect airflow beneath the vehicle to flow through the radiator and increase cooling. Air baffles are also used to direct airflow into the radiator and increase cooling. Air seals prevent air from bypassing the radiator and A/C condenser. Air seals also prevent recirculation of the air for better hot weather cooling and A/C condenser performance.



Water Pump

The water pump is a centrifugal vane impeller type pump. The pump consists of a housing with coolant inlet and outlet passages and an impeller. The impeller is a flat plate mounted on the pump shaft with a series of flat or curved blades or vanes. When the impeller rotates, the coolant between the vanes is thrown outward by centrifugal force. The impeller shaft is supported by one or more sealed bearings. These sealed bearings never need to be lubricated. With a sealed bearing, grease cannot leak out, and dirt and water cannot get in.

The purpose of the water pump is to circulate coolant throughout the cooling system. The water pump is driven by the crankshaft via the drive belt.



Thermostat

The thermostat is a coolant flow control component. It's purpose is to regulate the operating temperature of the engine. It utilizes a temperature sensitive wax-pellet element. The element connects to a valve through a piston. When the element is heated, it expands and exerts pressure against a rubber diaphragm. This pressure forces the valve to open. As the element is cooled, it contracts. This contraction allows a spring to push the valve closed.

When the coolant temperature is below 91°C (195°F), the thermostat valve remains closed. This prevents circulation of the coolant to the radiator and allows the engine to warm up quickly. After the coolant temperature reaches 91°C (195°F), the thermostat valve will open. The coolant is then allowed to circulate through the thermostat to the radiator where the engine heat is dissipated to the atmosphere. The thermostat also provides a restriction in the cooling system, even after it has opened. This restriction creates a pressure difference which prevents cavitation at the water pump and forces coolant to circulate through the engine block.

 

Why lose 5k on a replacement motor, buy a new radiator.

 

With all the help on here, nobody thought of just feeling the upper and lower hoses to the radiator?? One is hot and the other is cool. Thinking it's the thermostat.

 

Thanks, to be safe I'll do all three.

 

So we ended up adding a new thermostat and new fluids and now she seems like she's purring just right!

 

While we are on this topic, how does one go about removing air from the system?

I'm thinking I may have an air bubble in there somewhere. The car will run at 220 on a day like today (105 outside), but then jump up to 230 for no reason, and stay there for a while. Sometimes even a few miles on the highway doesn't take it back down.

I'd honestly like to see it at 190 all the time, just for peace of mind. But is that a reality in the Az. summer? I'm betting not.

S.C.

 

Nice. I'll give it a go.

S.C.