Thread: coolant leak, what and where to look

I know what you guys mean, with my car being low on coolant and probably having an air pocket in the system, my heat would go back to cold after acceleration or a bit of cruising. Maybe it has to do with the air pocket blocking circulation, and the coolant that is trapped in the radiator gets supercooled because it's not moving around, and then you get that burst of cold coolant?

If there's a better explanation I'd love to hear it

Im trying disagree with what you guys are saying about the temp droping do to air pockets but all my years of doing this i have only experienced the temps going up due to air pockets not properly allowing the coolant to cool the intrlernals and heating up the engine more causing the coolant to boil and as soon as you rev the motor you forcing the hot coolant past the sensor it usualy goes up . But in your case it wws a loose or broken sensor . Again stranger things have happend .

I have had a big problem with my engine temps dragging down to about 150f ..I replace the thermostat (stock) and put a stock radiator cap. On the mishimoto rad. And I'm using a Stock de water pump pulley..only happens in cold weather...so i put a nice big peice of cardboard in front of my radiator. it was the only solution to keep operating temps in 40* f weather

Can you explain how the heat turns back to cold then when you are low on coolant? Is it just not reaching the heater core? Or is there an actual block in the radiator trapping that coolant. I can understand that the engine itself is getting much hotter as there is no cooling action going on, but what's going on with the rest of the system?

Genuinely interested in what the answer is...

Because your causing the coolant to flow threw the heater core during reving or driving conditions . Also depending on the system if its low or has a pocket the thirmistat and close and not allow flow threw the heater hoses . If the car is siting still the wp fins are not spining fast enought to move coolant threw the heater core .

Thanks for that explanation

Basicaly come to a stop you loose heat ..start driving you get heat back from enough volocity to push coolant threw the heater core from the wp spinning faster . And like i explained earlier in my posts ive yet to experience a gauges act like that in the video from air pockets but like i said stranger things have happend. Air pockets make the motor over heat from lack of coolant contacting surfaces and exchanging heat ane will make the coolant expand faster boiling over . There is no such thing as a cold pickets of air inside a motor and besides the senser will not have enouh cooldown time to jump down to "c" like that one did.

And as far as the winter driving cold weather .. you will see the gauge drop depending in your mods to the coolant system . For example my b13 has no a/c condensor or thirmistat and a mezerrie electric wp amd a big old kyo rad and slim fans . Now driving it (mostly highway ) ocasionaly when its 30 degrees out and colder my gauge will drop down to almost cold and my autometer coolant gauge will read about 150'ish . It was running cooler before when it was NA but now its turbo so more heat to exchange . Btw i have my instroment gauge tapped in to the inlet coolant jacket from the radiator and my autometer gauge tapped into the stock location to get a reading both in and out of the motor . You might not see readings like mine if you have stock a/c or a big intercooler in front of the radiator. And ofcourse your gauge wont drop as fast as it did in the video it will take a min or two to drop down .