Fans wont turn off and overheating. 6A12TT

[Gt_Galant]

Hi All,

Thought id ask this here since its still a VR4 not the 6A13TT but with the 6A12TT (so should be similar, well kind of)

Ok hopefully someone can help me here as i try'd a few things and still doing the same thing.

When i start the car, it turns on fine, fans dont kick in yet, when the car reaches normal temp and fans kick in and they dont turn off anymore ? i have left the car running for more than 10 minutes and still wont turn off ? Anybody can help me ?

Things ive done :
replaced relays/fuses
replaced both fans
replaced radiator
replaced water temp switch (there are 2 i replaced)
replaced thermostat
replaced radiator cap

Also the car is overheating, the original radiator that was in the car, when i drive it, it would be on normal temp, but when i start to give it, the temp needle go's up but then slowly back down to normal temp.

Now i then replaced a few thing like the radiator, car go to normal temp, and if you give it, temp go's up and doesnt go down have to turn off the car - im thinking the radiator is stuff and maybe water pump ?

Now if you think i should replace something again that i already replaced (incase its faulty again) please let me know and will replace it as i have a fair bit of parts for the 6a12tt.

Also would it be maybe the ECU faulty ? was thinking of it the other day .

Thanks

 

[veegeeta]

Cracked head maby:mellow: Is it pushing water out the overflow ? Fans blowing the right way ?

 

[trotty]

maybe the cooling system needs to be bleed of air, you may have an airlock on 1 of the sensors causeing the fans to stay on and will explain the overheating problems as its seeing steam temp, and not flowing coolant properly. just a sugestion.

 

[Gt_Galant]

Shane - i was thinking it might be a cracked head but i dont get when the original radiator was in, it will only overheat when giving it, and then go back to normal, if driving normal ? Cause i was thinking the sandhand radiator i put in is stuff ?

Daniel - i did try to bleed the air out, well i think i did as theres a nut to release the air and did and then only water was coming out so i think i bleed it right.

 

[Size1]

You might need to do bleed it a few times. Air pockets could have formed. Also i had a problem like this on my old camry and it was a faulty temp sensor.

 

[hozza]

After market imobiliser?

 

[Gt_Galant]

Simon - Yeah will give it ago tomorrow to bleed it a few times, i just changed the radiator again, this time i know 100% this radiator is working perfectly, also i did change the temp sensor twice .

Nathan - car has no alarm or immobiliser .

 

[Size1]

i think that nathan was joking!

 

[hozza]

Nah, pre face lift vr4's when a after market imobiliser is installed, it causes the fans to start when you have just accessories on.
No one knows why.

 

[VOLK]

What are the water temperatures getting to when the gauge reads hot?

 

[Gt_Galant]

Joey - Honestly no idea, got no gauge for the water temp.

 

[VOLK]

Get a cheap datalogging cable or some other way to ascertain actual temps. Slight chance the water temp sensor is faulty and reading high. Does it start knocking when hot? Does the radiator physically feel hotter? Coolant level in expansion tank above the high mark when hot?

Had the system pressure tested? Losing coolant anywhere?

 

[naughtika]

i reckon its a dead waterpump...

troubleshooting I'd do since all of the obvious have been done..

get a cooling system test on your car..

also.. just a question..


does the 6A12TT have the resistor attached to the radiator/fans? like the 6A13TT does?

 

[Gt_Galant]

Okay i changed the radiator and done a few test, car was on for about 20minutes roughly, i changed all relays again incase, and still nothing, now i actually noticed once i turned my car off there is no pressure in the hoses, so i carefully took the radiator cap off and no pressure .

Would that mean a dead waterpump or radiator cap ? cause i really dont know how to test if you have a dead waterpump ?

Would that cause the run non-stop once it kicks in ?


Also dont see any resistor to the radiator fans

 

[naughtika]

when your cooling system is hot and there's no pressure.. that only means its leaking somewhere.. or the radiator cap didnt hold the pressure inside it..

can you please post pics of your radiator's fill hole? and also the radiator cap too!