Overheating
I wonder if anyone can help me, I just had my radiator repaired, it needed a new hot water tank as the old one was cracked. The thermostat was also replaced, as well as a new lower pressure radiator cap was added.
Now when I drive the car it overheats, I am not very mechanically minded, my uncle looked at the car, and he said it doesn't look like its the head or the head gasket because there was no bubbles in the radiator water when the motor was idling with the cap off. The oil is fine, nice and black, no milkiness or anything so it shouldn't be the engine block.
The only thing we noticed while the car was idling was the fan never came on, even after the car reached half way on the temperature gauge. When I put the air conditioning on the passenger side fan works but the drivers side fan still does not work (I have been told that both fans should work when the air conditioner is on).
My problem is, within a drive of a couple of KMs through town the car was giving me the overheating warning. On the 40 KM drive home, the radiator had lost over 5 litres of water. I had to stop on the side of the road to let my car cool down to manage to get the entire way home.
I took it to a garage, they pressure tested the radiator and found no leaks, kept perfect pressure. The garage mechanic tried telling me it was the intake manifold/gasket not sure which, he didn't seem interested in the fact that the one fan was not working. He informed me fixing the manifold would cost $500 at least.
So my real question is this, could the problem be caused by the fan, or is it more likely what the mechanic said? To be honest I got the feeling from him he was just looking for an easy way to make money.
Sorry for such a long post, I just wanted to make sure I got as much details in as I could, I really hope someone can help me.
Last edited by LunaEclipse; 14-10-2009 at 02:51 PM.
Not sure about the whole thing, but I just went to try a few things in my vt no fan runs when I start the car, switched A/C on 1 fan came on... let it heat up to regular temp turned A/C on again, still only 1 fan, im not sure what the deal with with the other not going on, but hope you find out.. wonder if my fan also has an issue or if it was designed this way. (Sometimes when im driving, when i come to a stop at traffic lights on warm days it sounds like both fans go) I cant be sure though, never go out to check lol, never concerned me since temp's never got dangerously hot.
If you look at the top of your thermostat housing you will see a bleed screw, start the car up until it gets to temperature and undo the bleed screw till water runs out of it. should solve your problem
Thanks for the quick replies, I will try that when my uncle gets home, I sort of know what has to be removed to get to the bleeder you are talking about, but I am not mechanically minded enough to try it by myself. Will give further progress on whether it works or not after I have tried it.
Your freedom ends where mine begins
If we ACTUALLY lost 5L of coolan then I can't see it being an airlocked thermostat.Originally Posted by black as
If you look at the top of your thermostat housing you will see a bleed screw, start the car up until it gets to temperature and undo the bleed screw till water runs out of it. should solve your problem
Did you note any areas in the enginebay that where wet with coolant and shouldn't have been?
You have to be loosing coolant from somewhere.
My money would be checking out the heater tap, it's localed on the driver side of the engine bay towards the back of the engine.
They have a habit of cracking fairly easily in my experience but are fairly cheap and easy to replace.
Good luck!
Exhaust Guru
An air lock can cause the coolant to go out through the cap and into the expansion tank, then it will over flow onto the ground. A cap that is rated too low will cause that as well.
I think it is a combination of an air lock and the new cap being too low pressure.
Actually its funny you say that, when I had issues with coolant disappearing I ignored it and kept topping up as I just didn't have any money to get it fixed (i was presuming it was a serious problem what was going to cost me loads) then about 2 month later i started to notice brownish texture at the bottom left part of my engine bay which I then noticed the leak from heater tap, when changing it... it literally crumbled I had to replace the hoses connected to it as well because the heater tap has broke and part of it was still in the hose... guess it hadn't been changed in a long time.
Slayer of Stupid Threads
This is what happened in my VR. I was loosing a shitload of coolant and was overheating a little. One night at work noticed a nice big puddle of coolant underneath the expansion tank.
Bled it everything was fine.
The radiator pressure cap needs to have a 135kpa pressure rating otherwise the cooling system will not be efficient. You also need to find out why your high speed fan isn't working. It should turn on when your coolant temperature gets above 109 degrees Celsius and turn off when the coolant temperature gets below 104 degrees Celsius. Your low speed fan (in conjunction with your low temperature radiator cap and possibly unbled cooling system) may not be adequate to keep the coolant from overheating. If the coolant overheats it expands and gets gets pushed into the overflow tank and then via the drain tube onto the ground. You need to check the high speed fan motor, relay etc.
the right idea,, but bad news if you open that bleeder up when the car is at nom. operating temp..If you look at the top of your thermostat housing you will see a bleed screw, start the car up until it gets to temperature and undo the bleed screw till water runs out of it. should solve your problem
because a commodore runs at above 100degrees, soon as you drop the pressure in the system the coolant will instantly evaporate causing a big mess an alot of burning
you have to do it while its at operating temp , and when the thermo opens , it will only let a bit out if you only crack it a little open , you can have the cap off the radiator while its running up if you want , then you can add more coolant after you bleed it then cap it off , have the heater on as well
Well my uncle tested the fan, it did work dirrectly connected to the battery. Bad news is we found out what the problem was, it is the head/gasket after all.
After the car was running without the radiator cap on, my uncle revved the motor, the water level went up and down for a while with the revs. After a while though there was a huge explosion of water, and it was boiling. My uncle told me it was caused from the exhaust gas getting released into the cooling system. Doesn't mean much to me, except that its going to cost me a fortune to get it fixed.
Thanks a lot for all the helpful advice though, I really appreciate it.
Posting Permissions
LinkBack URL
About LinkBacks
Reply With Quote
