Car is overheating?

[Redlyne_jr]

Alright guys car has been overheating lately i am not really sure what the problem is i am vouching for that i haven't properly bled the coolant system.. I was planning on replacing the thermostat because that is the only thing i can think of... has anyone used the TRD thermostat? from what i understand it lowers the temperature from 180 Degree F to 16- Degree F when opening...

Thanks

[sr20s14zenki]

You wont get as good of heat when you use the 160 just so you know. An improperly bled cooling system will do it for sure. Are the cooling fans coming on when it gets just over half guage?

[Joe-G]

Your car does get pretty hot, Your not leaking coolant though are you?? :D

[bmeier]

Use an OEM thermostat, the cooling system does not need any upgrades its very effective.

definitely bleed the cooling system properly, an improperly bled system wreaks havoc on these cars.

[Redlyne_jr]

alright i think the coolant isn't bled properly

[stvtec]

Are you sure the cooling fan is working properly?

[mr2mike]

I bet you have an air bubble(s) in there preventing proper cooling. Did you fill the coolant according to Toyota Specs? These cars have a totally different way of bleeding the coolant system. Follow it or else you'll have issues possibly including a bad idle.

[Redlyne_jr]

alright so today i got the car on a hoist, attempted to bleed the system properly and we thought everything was great.. one problem i am noticing is that the radiator fans are not turning on when the temperature is hitting ridiculous levels... one other thing i am noticing is that i am filling the filler cap to the top and then when i take the car for a spin or go anywhere i check the coolant levels only to see that they have dropped again... what is happening is as soon as the system is pressuring all the coolant is being forced over into the overflow container and the overflow is full as we speak and then it doesn't have anywhere to go so it is pushed out of the overflow down a tube that drips onto the lower cross bar... anyone got any ideas...

[962 kid]

I have a pretty good idea, don't think you'll like it though...

[stealth]

Check MR2OC.com for proper bleeding procedures.

[pf0sh0]

uh oh reese

[Joe-G]

Originally posted by 962 kid
I have a pretty good idea, don't think you'll like it though...

Care to explain??

Just throwing it out there, but what would happen if the water jackets were clogged? Is that even possible and would that cause these symptoms??

[stvtec]

See if you can bypass the rad fan relay and get the fan/s to work if you can you need a new relay, if not its probably a fan/s or wiring. I have no experiance with MR2's, but its a commen thing to check.

[sr20s14zenki]

Yep, if your fans arent turning on it could also be your coolant temperature sensor not working. Relay is less likely to go, more likely it is your sensor. Pour out your overflow tank, put it back in, fill it up to the proper level, fill your rad to the proper level, run the car, WITH THE RAD CAP OFF. watch for the bubbles, let it heat up to temp, or until the rad starts overflowing out the fill hole, then put your rad cap back on. That should properly bleed it. But yah, if your fans arent turning on, figure that out first. Coolant temperature sensor should cost you like 30$ tops. Im not familiar where it will be located, but its the one to tell the fan relay when to turn on.



good luck

[Redlyne_jr]

Originally posted by stvtec
See if you can bypass the rad fan relay and get the fan/s to work if you can you need a new relay, if not its probably a fan/s or wiring. I have no experiance with MR2's, but its a commen thing to check.
hey yes already did that, the foglights use the same relay so i switched the two out and the fogs turn on with both relays ... then we used a jumper to get them to turn on... the fans turn on with the jumper in place..

I am thinking of replacing the thermostat, coolant temp sensor..

[Redlyne_jr]

Originally posted by ~Porsche~

hey yes already did that, the foglights use the same relay so i switched the two out and the fogs turn on with both relays ... then we used a jumper to get them to turn on... the fans turn on with the jumper in place..

I am thinking of replacing the thermostat, coolant temp sensor..

[stvtec]

Originally posted by ~Porsche~

hey yes already did that, the foglights use the same relay so i switched the two out and the fogs turn on with both relays ... then we used a jumper to get them to turn on... the fans turn on with the jumper in place..

I am thinking of replacing the thermostat, coolant temp sensor..

Yep

[mr2mike]

Originally posted by ~Porsche~
alright so today i got the car on a hoist, attempted to bleed the system properly and we thought everything was great.. one problem i am noticing is that the radiator fans are not turning on when the temperature is hitting ridiculous levels... one other thing i am noticing is that i am filling the filler cap to the top and then when i take the car for a spin or go anywhere i check the coolant levels only to see that they have dropped again...

Its not bleed right, if you need to keep filling the coolant up and you have to put the car on a hoist.

There's an air bubble in there.

[Redlyne_jr]

how hard is it change the thermostat on these cars... and the water temperature sensor... i thought i wouild give these a whirl...

[heavyD]

Originally posted by mr2mike


Its not bleed right, if you need to keep filling the coolant up and you have to put the car on a hoist.

There's an air bubble in there.

To bleed it do you slightly jack up the rear wheels, hook up the service lines and open the two vent cocks and run the car with the heater on full blast?

[Redlyne_jr]

i think i might have figurerd it out my radiator cap or the filler hole that has the spring it is the wrong size and it is allowing bleed off thus my coolant levels are drasticly dropping... can anyone tell me what the pressure rating is on their cap or grab me a picture or something..

Thanks

[mr2mike]

Originally posted by heavyD


To bleed it do you slightly jack up the rear wheels, hook up the service lines and open the two vent cocks and run the car with the heater on full blast?

Yup.

Also something about the filler cap being half on to allow circulation.

[Redlyne_jr]

i think i have an idea of what the problem is i am going to try some parts associated with the filler cap, etc and take it from their...:nut: :nut:

[:EzE:]

when you gunna give my rad cap back???;) lol

[Redlyne_jr]

hahah asap.. when do you need it hopefully i can get a radiator filling nozzle assembly asap....

[:EzE:]

haha im jk :poosie: ... no rush im still waiting for my valve shims.
did you check mr2oc for a filling nozzle?:thumbsup:

[Redlyne_jr]

aight sweet mang...

[autosm]

Head gasket?

[Redlyne_jr]

Originally posted by autosm
Head gasket?

Nope not the head gasket a couple people thought that but no i was right just a minor leak... fixed it all up car is running and idling smoothly with no radiator leaks at all... ordered a 1.3bar blitz rad cap aswell:thumbsup: :thumbsup: