engine heating up

[05lcBMW]

the lower radiator thermostat gasket was no good so i replaced it. i took the car for a drive and ten minutes later the temp gauge was slowly going up and when i was in a stop i had to turn it off because the red light came on. can someone tell me if i did something wrong or what can i do to fix the problem.

[FCPGroton]

Is the car leaking coolant? Did you have a over heating issue before you started working on the car?

[05lcBMW]

Originally Posted by FCPGroton

Is the car leaking coolant? Did you have a over heating issue before you started working on the car?

the car did leak very little coolant so i took the sensor off and noticed that the gasket had a small crack on it, so i replaced the gasket. i never had a heating issue before.

[johnnyBgood]

Originally Posted by 05lcBMW

the car did leak very little coolant so i took the sensor off and noticed that the gasket had a small crack on it, so i replaced the gasket. i never had a heating issue before.

Did you bleed the coolant system, when you replaced that gasket you allowed air into the system, you must now bleed all the air pockets out or she will continue to overheat......

found this on the understeer link: Instructions on how to bleed the coolant system...

10) It really helps to have a friend lend a hand by sitting in the car revving the motor and keeping an eye on the temp gauge. Start off by removing the coolant reservoir cap and the plastic bleeder screw right next to it. Fill the coolant reservoir with a 50/50 mix of coolant and distilled water. Have your friend start the car, turn on the heater to full hot on the vent position and rev the motor to about 2500 RPM, if the temp gauge goes past the 12 o'clock position, shut the motor off, let it cool down and start over again. Watch the coolant reservoir, as the engine warms up the coolant level should drop, refill as the coolant is sucked out of the reservoir. Watch the bleeder screw hole also, when coolant with no air bubbles begins to overflow then you're almost done. It's a good idea to have some paper towels handy to mop up any overflow. Screw the bleeder screw back in (be careful to not break the plastic screw) and continue to rev the motor, you should see a continuous stream of coolant spraying in to the reservoir from the small hole at the top. Continue letting that spray in to the reservoir while your friend revs the motor for a couple of minutes, until the gauge hits the 12 o'clock mark, to ensure any remaining air is gone. If the heater is blowing hot air when you're revving the motor AND when the engine is at idle then your cooling system is properly bled. If your vents are blowing cool air at idle then you still have air in the system, try revving the motor more and/or squeeze the radiator hoses to help dislodge any trapped air. Once your system is fully bled, top off the reservoir and replace the cap. Check the coolant level in a day or two and top off as needed.

[05lcBMW]

ok thanks i will try what you said. i will post the results tomorrow.

[FCPGroton]

Originally Posted by johnnybayonne

Did you bleed the coolant system, when you replaced that gasket you allowed air into the system, you must now bleed all the air pockets out or she will continue to overheat......

found this on the understeer link: Instructions on how to bleed the coolant system...

10) It really helps to have a friend lend a hand by sitting in the car revving the motor and keeping an eye on the temp gauge. Start off by removing the coolant reservoir cap and the plastic bleeder screw right next to it. Fill the coolant reservoir with a 50/50 mix of coolant and distilled water. Have your friend start the car, turn on the heater to full hot on the vent position and rev the motor to about 2500 RPM, if the temp gauge goes past the 12 o'clock position, shut the motor off, let it cool down and start over again. Watch the coolant reservoir, as the engine warms up the coolant level should drop, refill as the coolant is sucked out of the reservoir. Watch the bleeder screw hole also, when coolant with no air bubbles begins to overflow then you're almost done. It's a good idea to have some paper towels handy to mop up any overflow. Screw the bleeder screw back in (be careful to not break the plastic screw) and continue to rev the motor, you should see a continuous stream of coolant spraying in to the reservoir from the small hole at the top. Continue letting that spray in to the reservoir while your friend revs the motor for a couple of minutes, until the gauge hits the 12 o'clock mark, to ensure any remaining air is gone. If the heater is blowing hot air when you're revving the motor AND when the engine is at idle then your cooling system is properly bled. If your vents are blowing cool air at idle then you still have air in the system, try revving the motor more and/or squeeze the radiator hoses to help dislodge any trapped air. Once your system is fully bled, top off the reservoir and replace the cap. Check the coolant level in a day or two and top off as needed.

Nice find. All cars should have a bleeder screw. That would make life so much easier.

[05lcBMW]

i tried what you told me and the engine started heating up. is this normal? how many times should i do it before giving up?
any other tip you can give me?
thanks in advance!!

[marti5]

Well you never give up!, make sure your fan is ok, roll up a newspaper with the car warmed up stick the paper in the fan, if the fan stops it rotating then you viscous coupling has gone.....another one is after warmed up check the bottom radiator hose and feel if its colder than the top one if so its your thermostat....You also say you replaced the thermo gasket I presume the car was ok prior to this ?, did you get the thermostat in the correct way around?

[05lcBMW]

i replaced the thermostat with a new one and it still heats up.

[05lcBMW]

one thing i noticed today was that the electric fan does not come on when i turn on the heater. it only turns on when i put the ac cold. is this normal?