Thread: How do I bleed the cooling system?

Was your temp gauge working fine before the LIM job? The temp guages are known to be faulty. But try removing the thermostat and see if it overheats still.

take the t stat out, fill the t stat hole with coolant if none is seen.

when you open the bleeder whats coming out? coolant air or bubbles?

take the t stat out, make sure its in the right way, then fill the engine via the hole in the lim.

If your car was stone cold when you started it, it shouldn't overheat in 20 seconds, especially if you put at least some coolant in. Have you checked to see if the coolant you put in was leaking? Maybe your LIM gasket was off centered when you re-installe everything and coolant is draining into the oil pan? Just a thought.

leave the thermostat out. take the radiator cap off and close the bleeder for a few minutes. sometimes it helps to jack the front end up. moves the air to the top of the engine.

you did put the belt back on right? if the belts on do you see any movement of the coolant in the rad.

run it with no t stat. see if the temp goes up fast, if it does your sensor is messed up maybe, or the wires to it. you did plug it back in right?

he did say he swapped sensors...could be a DOA sensor or he screwed up the wires/plug when removing it.

swapped the sensor? put the old one back in.

when i did my engine swap i reused my 233,000 mile old temp sensor vs a new one for a reason lol new suck.

he said he broke the old one removing it..

Temp gauge was working fine previously however the plastic clip got broke at disassembly so I replaced it with a bwc one.

so put the old one back in and tape the plug on the sensor?

Well, we know an engine doesn't overheat that fast, unless completely dry... So the assumptions must be made.

1. There is coolant in the system.
2. The thermostat is working correctly.
3. The water pump is circulating the coolant.
4. Air has been removed from the system.

Is all it takes... So if your temp gauge is climbing immediately like that and the other assumptions are not probed false then you just move on to the next hypothesis.

1. The temp sensor is bad.
2. The wiring is bad (sensor to pcm).

None of this means the engine is actually running hot, but if sensor is reporting it as such, will cause the pcm to put engine into limp mode.

Check the sensors, I'd have to look it up to check resistance value. And replacing it doesn't mean the second one is good either... Lol. But shotgunning parts at a problem sucks too. Are you sure when you broke the sensor, you didn't do damage to the wiring at the plug/wire which attaches to the sensor? Can't be running hot like that unless you left something in there blocking coolant flow. When you filled coolant and started engine with radiator cap open (thermostat removed), water was moving?

Originally Posted by Brammer

The old one was thrown away. Just removed the new one and got a replacement, same results on this one too...

Any other good ideas? Removing the thermostat and running it without one it did the same thing.

Then your car is not actually overheating, the temp gauge is just saying it looks like it is. SgtMarshal said his temp gauge will reach 260* before the thermostat opens, so his gauge is way off. I'd hook up a scan tool to see what the actual temperature is.