Coolant Buzzer

[davegttph1]

Yesterday I took the rex to work, started fine in the morning everything was normal, parked up and left it for 3hours + until dinner time. I started the car, again everything fine. 100yds down the road the coolant buzzer came on (annoying loud pitched sound aint it) so I coasted about 500yds down the hill and went into the petrol station, by now the alarm had gone off, I turned off the car and with the engine still being cool I thought it was OK to check the coolant levels, everything seemed normal, the AST was full, the filler neck was full and I could see coolant in the engine under the other metal cap. everything seemed fine, so started her back up and carried on with my journey got home and got back to work no probs. Same happened when I was on my way home at 5pm too. Again came to work this morning and the buzzer went off again. WTF. the car is running the same as usual. not over heating, coolant system seems fine, I cant work out what the crack is, any idea guys? Stupid thing...lol Im gonna check the coolant at dinner before I leave for home again, My guess is everything will look fine but the buzzer will come on again.

[nikp]

Check the coolant level when everything is stone cold. Sounds like an air bubble to me. All the water needs to do is drop just under the sensor for it to go off, so won\'t have to move much.

[Oedipus Rex]

if your coolant is up to the top but the buzzers going off then you probably have an air pocket in there. I\'ll get to that in a minute, you mention the filler neck and the metal cap as being different. You do realise you have to fill the coolant system from the neck under the metal cap in the middle of the engine bay yes?

Anyhow to bleed the system of air you need to release the highest part of the engine, which is a coolant tube that connects to the back of the UIM.

Unclip that and then open the main filler cap (metal one yellow sticker). You need to get a decent head of coolant behind it to push it through, I use a funnel and then gaffer tape around the sides. FIll the funnel up with coolant and keep it coming until its coming out of both the pipe and the connector at the back of the UIM.

reconnect pipes, un-gaffer the funnel (or whatever you use), put filler cap back on and hopefully bob is your analogous uncle.

[davegttph1]

Right thats actually what I was thinking, air lock. when I said metal cap and the filler neck, I called it the filler neck cause thats what it says on it, the plastic thing behind the drivers headlight, but I do understand we fill it at the metal cap with yellow sticker place thanks.

whats the UIM out of interest then I can have a look later when I pop back out at dinner. just one slight problem is I aint got no stuff to do all that at dinner which means I have to go home etc and then the coolant would be up to temp. Not gonna cause any damage doing this am I?

[Jonathan_F]

I think it will be electrical. If you disconect the plug the alarm sounds. Copper grease the connections at the plug. There is a second connection in the loom thats a right pain to find, about where it comes out of the engine above the plugs.

Jon

[Oedipus Rex]

Right thats actually what I was thinking, air lock. when I said metal cap and the filler neck, I called it the filler neck cause thats what it says on it, the plastic thing behind the drivers headlight, but I do understand we fill it at the metal cap with yellow sticker place thanks.

whats the UIM out of interest then I can have a look later when I pop back out at dinner. just one slight problem is I aint got no stuff to do all that at dinner which means I have to go home etc and then the coolant would be up to temp. Not gonna cause any damage doing this am I?

Jonathon is of course correct and it could also be a electrical problem. When I had yhe same problem as you it turned out to be a faulty cap on the AST that created an air pocket in the coolant system. I guess many things can cause the same  symptoms. Personally I\'d look at an air pocket first as its a reasonably common problem but whos to say I\'m right?

As for damaging it well, I guess it could be possible but as long as you stay off the boost and don\'t push it too hard I can\'t imagine that you\'d do it any harm on a short drive back home. That said I don\'t want to say that and you end up cooking anything. Maybe give Clive or Carl or someone a bell and grab their advice before you run it home.

[davegttph1]

I checked it over at dinner and the water had gone from the filler cap (metal one) so topped it up with water, thats all I had available. took the cap off the AST too, as I filled the filler part the water level rose in the AST, topped them both up and drove home, everything seemed normal, parked at home for 40mins and no leaks that I could notice. Will leave it now til I get back of holiday and see if its lost anymore water. Think I could have a problem with my AST cap actually, going to look into it but its all aftermarket my AST. think its something to do with WGT so might give them a bell when I get home. Will probably flush the whole system and start again with straight coolant and see where that takes me.

Thanks for the help