Thermostat got messed up

[HuGo]

Yesterday on my way to work, my heat gauge went up a little passed 3/4 before getting to the red. I stopped turned it off and called my dad. So im like, why doesnt it work this time, we just replaced all the tubes and nothing is leaking at all. So hes like, turn on the air conditioner and drive a block and tell me. So im like, it went a little higher, so hes like, go back to the gas station and turn it off. My dad just gets here and is like, "open the hood turn the engine on" I just see him touch 2 tubes, and hes like, its the thermostat, he sayed they touched or tapped, something like that, so whatever that means. So i took my moms car. So today he bought the thermostat and we replaced it.

It was weird, he told me keep an eye on the gauge. It went to 3/4 again, hes like, rev to 2k. It went back to half ways. I let it go, goes back up little by little, hes like turn on the fan. Goes down. I turn off the fan, goes back up, then he says turn on the heater. The heater wasnt blowing warm air at all. It stays at 3/4 *gauge* So he goes back to the motor, idk what he did, the heater starting blow hot now. It went back down to half *gauge*. So it was doing this back and foward back and foward so we let the engine running for like 15 mins with the heater on. He told me that its because theres a little bit of air in the tubes so it needs to get rid of it, thats why it was going 3/4. He says its mixed with air and anti freeze, so we need to wait till the anti freeze is the only thing running fine. So after those 15 mins, he gauge went back to half. So he told me to go drive it. So now it works fine.

So he told me to be looking at the gauge every time i possibly can and if it goes to 3/4 to turn it off. He says if its doing the same problem, we will need to clean the radiator. What impressed me is that he knew the problem by touching just 2 tubes. One was way hotter than the other. So he explained to me what was up. Then when he took out the old thermostat, he showed me how the springs open and close and stuff. But he said he changed that 2 yrs ago and it shouldnt have messed up so quickly already.

He also bought a gas pump i think, its pretty long, he said we will need to change that pretty soon too.

[aceyx]

Originally Posted by 1996Bmw318TI

What impressed me is that he knew the problem by touching just 2 tubes. One was way hotter than the other. So he explained to me what was up. Then when he took out the old thermostat, he showed me how the springs open and close and stuff.

When you know how something works, you can often intuit what's going wrong and from there, fix it. Knowledge is power--learn as much as you can from your dad. Ask him questions (but don't pester him) and ask if you can help fix the car, rather than just handing it off to him. You will save a crapton in money over the years, and get the satisfaction of doing it yourself.

After the hoses were replaced, the system needs to be bled (get the air bubbles out) This is an easy procedure, something you can start with.

A search should bring up how to do it.

[J!m]

Also known as "burping" the system.

The ti cooling loop holds air easily, and often needs to be burped several times to get all the air out.

[HuGo]

Originally Posted by J!m

Also known as "burping" the system.

The ti cooling loop holds air easily, and often needs to be burped several times to get all the air out.

would that be the reason why it kept heating up and going down and up again?? It runs perfectly fine now, temp. is at middl.e

[J!m]

Increasing the RPMs moved the coolant around to cool the engine. At idle, there is low turbulence, and the air just sits still, creating hot spots.

The pump pumps, but the system also relies on two other methods of moving the water: siphoning and convection. If there is air, these last two methods do not work, so essentially the coolant system works at 1/3 capacity when it has air in it.

Lack of heat is the main clue, as the air tends to get caught in the heater core easily...

[HuGo]

Originally Posted by J!m

Increasing the RPMs moved the coolant around to cool the engine. At idle, there is low turbulence, and the air just sits still, creating hot spots.

The pump pumps, but the system also relies on two other methods of moving the water: siphoning and convection. If there is air, these last two methods do not work, so essentially the coolant system works at 1/3 capacity when it has air in it.

Lack of heat is the main clue, as the air tends to get caught in the heater core easily...

kool.