Getting a bit hot

[Shortstuff]

More cooling problems possibly!! I had to drive around looking for a parking space for about 25 minutes today, so it was all stop - start driving and very low speeds.

When I eventually parked up, I tried to pop the bonnet just to check everything was OK, and it wouldn't go. I got it open by leaning on the bonnet while my girlfriend pulled the release, but once open, everything in the engine bay was red hot.

The bonnet stay was too hot to touch and the reason the bonnet wouldn't open properly was that the release cable was so hot it had expanded or just stretched slightly when I pulled it (once it cooled down it was fine again).

The radiator fan was cutting in OK, the car didn't boil over and the temp guage was steady and under 1/2. All the pipes I can reach get hot and pressurise. The radiator gets hot right through,and the cooling system is all bled well. I flushed it all out and found no blockages in the radiator or heater core.

There are a few niggles with the cooling/heating system which are:-
The heating will not adjust. It just blows hot air most of the time, but very occasionally switches to cold.
The car uses about a litre of coolant every 300km.
There is a small very coolant leak at the back of the block
The heater valve doesn't open/shut by vacuum, and it doesn't make any difference to the heat of the air going into the car when I operate it by hand.

A failed head gasket crossed my mind, but as I said, the car doesn't actually boil over and there doesn't seem to be any oil in the water or vice versa.

Any ideas???? I'm really getting stressed about this as I can't seem to get to the bottom of any of the problems i've mentioned.

Sorry for the long post. Just trying to give as much detail as possible.

 

[PaRaDoX]

ok mate, i had a VERY SIMILAR issue,
i had coolant pissing out EVERYWHERE and it got to red a few times and had to kill the engine before it blew up,

my issue was the thermostat, it was jammed causing the thermo fan to come on later and sometimes not at all, i havnt changed it because im poor just made the thermo fan come on and stay on always

fixed the issue right up no more coolant leaks

see mine was fine at say 80km/h but as soon as i hit low speeds/idle it heated up again, i drive in peak hour and it was shocking...

id be geussing its the thermostat mate, they cost like $20?

 

[Immortality]

some of the heater controls are vacuum operated so you might have a vacuum leak somwhere. there is vacuum canister under the front passanger side guard in front of the wheel (round looking thingy) followthe vacuum line from this back and see if there are any breakages/leaks etc. where is the coolant leaking from at the back of the engine?? if it's coming from around the intake manifold i'd suggest trying to tighten all the intake bolts just a little. if you look behind the center panel on the drivers side foot well and operate the temperature selector you will see a short steel shaft moving, when you select full cold it should be pushing down on a plastic button which is the heater shut off valve. when you turn the flow control selector can you here a vacuum sound?? a new thermostat and radiator cap can't hurt, with the cooling system loosing coolant it may not be presurising properly causing the coolant to boil??? maybe replace the temp censor the the ECU as well

 

[Shortstuff]

There's no vacuum sound when I adjust the heat controls, but there is when I use the flow selector. Is the temp control vacuum operated or is it just the metal rod that comes down from the control panel?

I can't see a plastic button around the area you're talking about so that may be another problem. The valve also feels really loose if I take the control rod off it and just move it by hand. I'll get some pics in a bit.

I can't see exactly where the water is coming from, but the area round the thermostat housing is dry. I've got a feeling it might be the rear welch plug in the passenger side head which will be a beast to get to! The car isn't actually boiling over, just the engine bay was all absolutely roasting. Everything was too hot to touch when I stopped the other day! I just fitted a new surge tank and pressure cap and that helped a bit( the coolant was bubbling out of the top of the tank before I did that), but now the system pressurises properly, it has shown up the small leak at the back of the engine I mentioned.

I'll do the temp sensor this week as it doesn't look as if it has been touched for a while. Any idea how much they are?

 

[Shortstuff]

Got some pics now. It's definately a Welch plug leaking. It was fun trying to stick my phone down the back of the engine to get a pic to check. Looks like the heads will be coming off to do that anyway, so i'll change the thermostat at the same time.

Also got a pic of the heater shut off valve to check if anyone can see anything amiss there. More pics if needed!

 

[Immortality]

There's no vacuum sound when I adjust the heat controls, but there is when I use the flow selector. Is the temp control vacuum operated or is it just the metal rod that comes down from the control panel?

I can't see a plastic button around the area you're talking about so that may be another problem. The valve also feels really loose if I take the control rod off it and just move it by hand. I'll get some pics in a bit.


I'll do the temp sensor this week as it doesn't look as if it has been touched for a while. Any idea how much they are?

sorry, don't know how much the temp sensor are, only the flow control selector should make a vacuum sound when you move it, the temp control just moves a rod. i've taken a couple of pics from mine, one with the control set partially warm, you can see how the rod/arm are away from the button i mentioned, the second with it full cold and the arm pushing the button in. just had a look at your pick and it looks like the littlebutton has come away from where it should be or maybethe little black vacuum hos is blocking it maybe??

 

[Immortality]

took another look at your pick, the button assembly has definitly come away from where it's suppose to be screwed down. hopefully you'll be able to see how it goes back from my pics

 

[Shortstuff]

Thanks for the pics. Yeah, that button bit is loose and possibly broken I think. I'll grab one from the wreckers and see if that makes any difference on the heating side of things.