Advice on cooling system and air-con?

[CharlieCroker]

So the car is in a state ready to drive and test but I noticed after only a 20 minute run that the temperature was climbing. Is the air-con linked in anyway to the cooling system, seeing as I have removed the unit and plugged the two pipes that are off the radiator that were remaining, would that cause a blockage? 

[Clive59]

The Otter switch in the radiator stops/starts the fans. Simple.

The temperature sender is located on the middle water pipe near and above the distributor, you should see a wire coming from it. It drives the temperature gauge. The temperature will only indicate correctly if the 10V voltage stabiliser is working, so this could be your problem. Does the engine get to temperature and fans cut in/out around 90deg? Try this at idle.

 

And of course the thermostat to regulate water temp, and I think it should be fully open around 80-85 deg. You could remove it and test in boiling water. But, I am not sure how easy it is to get to either??

 

You need to work out which is the faulty bit. You might have a real problem or a sensor indicator problem.

 

Since you have no aircon fitted now, there should be no issue. Presumably the heat exchanger inside is still there, and it will have water pipes going to it. You should feel these getting hot inside if you turn the heater on.

 

Mine also had aircon removed, but not sure which pipes you mean. Do you have a picture?

 

Good luck!

Edited September 15, 2014 by Clive59

[CharlieCroker]

Don't have a picture, but I removed the aircon unit and the smaller, is it a condenser? So all those pipes went. The two I am referring too are the two at the front of the car that seem to come directly from the radiator. I think maybe I need to open up the heating controls inside the cabin, set them to hot and see if that works. Fans come on at 90, but I don't think there is circulation in the system. Plus the expansion tank never settles at half full, it's always well below that level. Doesn't seem right to me, just further investigation needed...

[USAndretti42]

The air conditioning system shouldn't be connected to the radiator as it doesn't use water so I don't know what pipes you mean. The condenser and its pipework are a separate system.

[CharlieCroker]

Cheers Trev, you know what it is, my mind has started playing games with me, just had to ask the question to clear my doubts! I'm now positive it's an air lock as when I filled the system I forgot to open the heater control to 'hot' so I reckon that was the problem. 

[Herc]

I always remove the top hose from the front of the engine when filling up the cooling system.  It seems very prone to air locking as that is about the highest point of the system.  I've got a butterfly key on the hose clip to make it easy to do.  

 

There may be some proper way to do it, but that seems to work for me.

 

Herc

[CharlieCroker]

Is that the hose that comes off the thermostat housing? The manual says in the event of an airlock to release the hose off the back of the engine, I did that and the pipe was dry, shouldn't that be full with coolant?

[Herc]

Yes, the one I was talking about is the one off the thermostat housing.  I slacken off the hose clip, ease the hose back off the pipe a little, and fill up the reservoir until fluid starts to trickle out, then push th ehose back on and tighten it up.  

 

This has worked for me, but it's just something I improvised when I had similar symptoms to you.  The more expert guys on the forum may have  a better way of doing this.  

[CharlieCroker]

If it works then I'll definitely give it a go. Sounds logical to me, I'll try anything if it works. Only two issues stopping me from driving this car now, this and crap brakes, which I intend to bleed this weekend.

[andy b]

I have just done my cam belt the way i burp the excel is pump the top hose once full and it will act as pump pushing the water around and expelling the air to the tank.

By removing the ac rad you should find no differences in temp it will still run within thermostat and fan stat  settings. about 90deg fan start with about 5deg dif to cut out. if you still have the ac compressor fitted disconnect the  wire connecting the electric clutch

then if the fan stat fails you can switch on the ac and the cooling fans can run keeping you going. i had the fan stat fail in heavy traffic so i just switched on the ac and cooling fans run until i got a new stat 

The discharge pipes you have disconnected from the ac are fine.

andy b 

[benjamincalleja]

Hey guys, my fans cut in the minute i turn the car on and at any temperature...not normal..  any ideas?  the temp sender was just replaced but cant be faulty because the vdo dial shows the car heatings up and cooling down..

[Choppa]

If you are happy that the otter switch is working as it should I would look at the radiator fan relay. It's always possible that a PO has added a switch somewhere that can be used to manually turn the fans on, probably under the dash somewhere, happy hunting!

[CharlieCroker]

This has now been solved, it turned out that I simply left off the hose from the rad to the expansion tank. Apparently this tube helps prevents air locks and vents the system, quite an easy mistake to make when you have a billion other things to worry about after the engine is out. 

[benjamincalleja]

ah for me it hasnt i need to clarify as my above is incorrect, when i turn the car on the fans dont enrgise straight away, they come on when they car hits 80 degrees and then just never turn off....is it a temp gauge sender?  (someone send this ONLY sends temp to the VDO gauge is this true?)  or is it a problem with the otter switch thing?

[pbharcourt]

The otter switch thingy, relays and fan are a seperate system to the temp gauge and temp sender unit.

[benjamincalleja]

Thought so. But why would it energise the fans at 80, shouldn't it only kick in at 90ish? It must at least be partially working to detect temp at all? Could it be the wrong part? Not sure if it's relevant but just had it in for tanks change to aluminium and also water pump rebuild, is there anything involved in that which could cause this? Didn't happen before