Radiator Fans Always On & Overheating ?

[Gt_Galant]

Hi,

i have two problems, its not a fto but it is a 6a12 engine so should be the same.

Okay problem one :

Radiator fans are always on ! Once you start the car, fans dont kick in, but once they kick in they never stop ?
I have changed the thermostat, as the one that was on the car was missing the inner rubber, but still always on.
I have also noitced that the top radiator hose, there's no pressure when you push on it and you can basically open the radiator cap carefully without it exploding, could it be that the newer thermostat is faulty ? or ?

Also i was thinking maybe the relays in that box in the engine bay, but dunno, i do have spare ones as well, but was hoping it was that thermostat cause the originally one was missing the rubber and would think it was always opened.


Second problem :

Overheating, this one is a tricky one, when the car is in normal operating temp, the needle basically sits in the middle like normal but when you start giving the car the needle starts to climb up and if i stop accelerating hard, the needle will start to go down slowly back to normal temp.
I have changed the 2 sensors thats next to the thermostat, with so spare one i had from another engine, could they be faulty as well ? or could it be something else ? keep in mind that the radiatir fans are running non-stop.

(Cause originally when i brought my daily it was doing the same thing about the temp going up, but when i changed the sensors it stayed to the normal operating temp, this is the second car and thought it may be the same problem, but it still could be maybe faulty sensors ? just want you guys opinion please)

Thanks

[Kustom]

Well if you have no pressure then that would lead me to believe you have a leak somewhere.

[PHIL069]

Blocked radiator or stuffed water pump.
Are you loosing coolant?
When.....engine cold.......radiator cap off......fill the coolant....run engine.....do you see movement in the coolant through the cap opening as the engine warms up, ie; coolant swirling, bubbles rising to the top, eventually starting to overflow as it heats up?

[Gt_Galant]

Kustom - no leak anywhere, drove it around the block a few times and idle and drove it again all up about 40minutes and no leak.

PHIL069 - radiator i flush it with a hose tap and comes out at the bottom fast and fine, the raditaor once i look inside it after driving it is full, so not loosing any water.
water is rising overflowing spiting it out as the engine heats up going to normal temp. Isnt that normal ? or ?

the water is hot, but if i put the radiator cap on, water is hot but feels like no pressure ? once you turn off the car after driving for a bit, after a minute or 2 you can take off the cap and hear not much pressure ?

thanks .

[PHIL069]

Normal....from a cold start, as the coolant heats up it will rise and overflow, if you have the radiator cap off. If you have the cap on it will overflow to the overflow bottle/header tank.

How does your oil look? Is it milky?

Have you changed your radiator cap? It might be faulty and not holding pressure

[Gt_Galant]

Hey,

Oil is not milky, looks normal (one of the first things i checked), and i forgot to mention i did change the radiator cap with a spare one i had in my laying around in my garage .

Cause when i brought the car it had the wrong radiator cap on it, and the guy i brought it from told me it was the wrong one, so i changed it to the proper one .

Its just weird cause needle only go's up if i give it hard only, normal driving i dont really notice it going more than half, and once i stop giving it on the gas hard, it starts to go down to roughly normal temp (half)

If it was a blown head-gasket (i doubt it) wouldn't the temp needle go to H and stay until you turn off your car ?

Could it be the whole radiator is stuff'ed ? even though its flowing normal ?

[Taz]

Just swap it out for another radiator off a willing club member here for an hour or so, see if the same problem persists. if it does then you know its not the radiator, if it does, then swap the piping over see if its in the pipes etc - play the game of elimination

[PHIL069]

One of our members had a simular issue not long ago, read through his thread. I think it will solve your issues
http://ftoaustralia.com/v3/viewtopic.php?f=21&t=25887

He had good coolant flow, coolant level rising and falling with engine temps, hot when going quick, cool down when taking it easy..........he had a blocked radiator as I suggested earlier

[Gt_Galant]

thanks guys, especially PHIL069, i actually have 2 spare radiators, one came out of a half cut that did about 90,000km so i might give that a try and pop it in, instead of trying to flush the original radiator thats in there.

Hopefully will do it within the next couple of days, fingers cross that it works, but would that expalin the radiator fans running non-stop as well ?

Thanks

[PHIL069]

No worries, Hope I'm helping your issue

Another idea for your fan issue..........In the FTO engine bay fuse box there is a relay for the radiator fan, if this is faulty and sticking on when activated it would make the fan run constantly. Your fuse box may look different, but it still should have this relay.
In the picture I have pointed out the correct location for the FTO, it is known as.....A-57X Radiator Fan Relay

[Gt_Galant]

Thanks

yeah i was thinking relays but might change them since im replacing radiator, with my car its :



the top 2 on the right are the radiator fans relays (lo & hi) and the bottom left is just the fuse, a bit different to the fto, but find it weird theres a hi & lo, but will replace them with different ones, hopefully all that does the trick.

Will let you know in a couple of days how it go's once i replaced all those stuff.

Also i notice something today, i was warming up the car with the radiator cap off and when the fans kicked in it started splitting the coolent out high and fast as if there was pressure pushing it and quickly unplugged the fans and didnt spit like it did, is that normal ? lol thought i blew something cause it made a loud some but was the water spilling on the fans and fans spashing it everywhere haha

[PHIL069]

I think change your radiator and take it from there

Sounds like your engine heated up.......the thermostat opened.......fans kicked in.........the radiator is clogged, so the pressure/heat had no where to go but up.

[Gt_Galant]

haha no worries will let you know the results soon thanks again

[payaya]

Why do people always change their thermostats and make things difficult when the main cause of overheating at speed is a blocked radiator?

People always change their thermostats when they rarely fail. If your thermos switch on and your car overheats about 99% of the time its a blocked radiator. Its not your thermos as at speed thermos do stuff because at speed air naturally flows through the radiator. Its not your sensors (cant be stuffed explaining it). Shoving a hose in your radiator and having clean water flow out of it doesn't unblock your radiator.

[Gt_Galant]

Well i actually had to change my thermostat (and thought that was the problem) cause the inner rubber was gone (no rubber), so basically it was like it was opened at all times.

Plus my daily galant was overheating when i brought it 3yrs ago, i changed the thermo, relays even a brand new radiator and the two fans, and it end up being the sensor on the thermo housing, thats why i changed the sensors thinking this galant was kinda the same problem cause its doing the same thing, so it can be a sensor.

"Shoving a hose in your radiator and having clean water flow out of it doesn't unblock your radiator" - doesnt hurt trying champ (you learn from your mistakes) but will be changing the radiator soon as i got one ready to be put in and hopefully that will solve the problem

[PHIL069]

@ GT_Galant
@ payaya

[Gt_Galant]

Okay,
i changed the radiator and the 2 fans, now i can feel pressure in the hoses but still overheating and it looks worst than what it use to do, now it will go nearly all the way to "H" ?

Could it really be a blown head gasket ?

Also i changed the 2 relays and still no luck with the fan issue once it kicks on it dosnt stop .

[PHIL069]

Are you sure that the replacement radiator is in good condition? If it's been sitting around it could have chocked itself with corrosion.
Could be your water pump, if it's not circulating the coolant then the coolant wont go through the radiator to cool.
Could be an old radiator hose, if it's lost its structual abilities then the hose could collapse/squeeze together when the coolant attempts to flow though it at pressure, stopping the flow of coolant. Watch your hoses when the engine is operating at temp. Feel your hoses when cool to see if they are over soft or hard and brittle.
The coolant could be leaking from the head gasket to; oil galleries or to the outside of the head. To test this you will need to get done or do a cooling system pressure test.
If you still suspect a head gasket go and get or do a compression test.
Again good luck

[payaya]

Well i actually had to change my thermostat (and thought that was the problem) cause the inner rubber was gone (no rubber), so basically it was like it was opened at all times.

Plus my daily galant was overheating when i brought it 3yrs ago, i changed the thermo, relays even a brand new radiator and the two fans, and it end up being the sensor on the thermo housing, thats why i changed the sensors thinking this galant was kinda the same problem cause its doing the same thing, so it can be a sensor.

"Shoving a hose in your radiator and having clean water flow out of it doesn't unblock your radiator" - doesnt hurt trying champ (you learn from your mistakes) but will be changing the radiator soon as i got one ready to be put in and hopefully that will solve the problem

If your thermostat was not sealing your engine will be getting more cooling than required.

You got to understand the basics of a cars cooling system. If its overheating at any speed over say 50km/h it's either your thermostat, blocked radiator or the dash temp sensor is giving a false reading. Then you can eliminate the thermostat if your engine is cooling down. If a thermostat is stuck closed your car will be overheating and not cool down.

So again if your car is overheating under load and then goes back to normal temp when backing off it is not electrical related. Cooling at speed is all mechanical. I dont car if the sensors are screwed or not giving the correct reading, sensors cannot make a car overheat while travelling at speed!

Think about race cars! They don't have fans and never overheat! Why is this? Just change your radiator! Simple!

Blocked radiator is the number one reason why far why a car overheats! Why doesn't one think to check there first?

[PHIL069]

He changed his radiator, but it didn't fix his overheating.
I am thinking replacement radiator is used and also blocked/corroded.