header tank & expansion/top up/overflow/burp tank not full

[fionuhthevan]

firstly, i've read SO MANY different stories on this, and posted my own questions on facebook with a few snotty replies. first time van/car/anything owner, so please try to be kind.

we bought the van.
the van appeared to have a leak.
we took it to the garage (mid september).
they told us we had a coolant leak.
pipe was repaired. the leak was gone.
a handful of small trips later the temperature gauge was flashing.
we topped up the expansion/top up/overflow/burp tank as advised.
we also purchased a new header cap.
never had the temperature gauge flash since.
obsessively checked the expansion/top up/overflow/burp when engine was cool after every trip.
* one month later *
after plenty of local trips and a 200mi trip we noticed the expansion/top up/overflow tank is empty.
we checked the main header tank and noticed that is only 3/4 full.
the temperature gauge hasn't flashed, so this is confusing us.

we're pretty sure we don't have a leak since it has only just been checked.
if we did have a leak, would this be a visible, under the van leak?

could we have an airlock in the cooling system? how do we need to do to troubleshoot this?
and if we do have an airlock, do we bleed the system and start from fresh?

[TONYT25T25]

Hello, you should get a good response here as there is a wealth of experience, this problem has been addressed very recently by another member with similar problems to yours, do a search for coolant leak in the search bar, and have a read of the wiki,  it would help if you stated the type of engine you have and where was the initial leak the garage repaired. That should start the ball rolling. 

[Mocki]

I am pretty sure I already answered this on Farcebook ......

The system is very simple....
The headertank ( the one in the engine bay ) should always be full to the brim, and the top up tank ( behind the number plate flap) should be full to the max mark when cold. When the engine is up to normal running temp the coolant expands and is pushed into the top up tank, when the engine cools down the coolant is sucked back into the header tank

If the leak was fixed, but the system wasn’t blead then the top up tank would become empty , as the main header tank would suck more out than it put in as the air moved around the system


The flashing red light in the temp gauge has two functions ....
1. If the gauge is above 3/4 and it's flashing it means over heating
2. If the gauge is below 3/4 and it's flashing , it means low coolant in the header tank.

If it's says low coolant , and the coolant isn't low then it's an electrical issue , and simple fault diagnostics will need to be employed !

[fionuhthevan]

Hello, you should get a good response here as there is a wealth of experience, this problem has been addressed very recently by another member with similar problems to yours, do a search for coolant leak in the search bar, and have a read of the wiki,  it would help if you stated the type of engine you have and where was the initial leak the garage repaired. That should start the ball rolling. 

sorry! musn't have updated the signature before posting.
'89 1.9 petrol WBX and the repair was a coolant pipe break on the way to the radiator. 

 

[fionuhthevan]

I am pretty sure I already answered this on Farcebook ......

The system is very simple....
The headertank ( the one in the engine bay ) should always be full to the brim, and the top up tank ( behind the number plate flap) should be full to the max mark when cold. When the engine is up to normal running temp the coolant expands and is pushed into the top up tank, when the engine cools down the coolant is sucked back into the header tank

If the leak was fixed, but the system wasn’t blead then the top up tank would become empty , as the main header tank would suck more out than it put in as the air moved around the system


The flashing red light in the temp gauge has two functions ....
1. If the gauge is above 3/4 and it's flashing it means over heating
2. If the gauge is below 3/4 and it's flashing , it means low coolant in the header tank.

If it's says low coolant , and the coolant isn't low then it's an electrical issue , and simple fault diagnostics will need to be employed !

thanks! i have just seen that... that'll be me.

i'm going to go ahead and assume the system hasn't been bled/we have air or whatever so honestly i think we're going to flush the entire thing and start from fresh, with clean pink ass coolant.
 

[Stesaw]

clean pink ass coolant.

Good ol pink ass coolant, I think my a*** is just fine without it though!  :rofl

Sorry couldnt resist.

The system is a lot simpler than at first glance. Probably best to do a complete drain of it, then you know it's all fresh.
However if you are doing that I'd suggest just putting water in to save you wasting money filling it up with fresh antifreeze for it to only pi$$ out everywhere..

Although maybe that might be better to do in the warmer months.

[TONYT25T25]

Hello, you should get a good response here as there is a wealth of experience, this problem has been addressed very recently by another member with similar problems to yours, do a search for coolant leak in the search bar, and have a read of the wiki,  it would help if you stated the type of engine you have and where was the initial leak the garage repaired. That should start the ball rolling. 

sorry! musn't have updated the signature before posting.
'89 1.9 petrol WBX and the repair was a coolant pipe break on the way to the radiator. 

My error signature was there I just missed it.  Was the initial leak in the plastic piping or rubber hose, and have you had a look at it since after the engine has fully warmed up.

[Mocki]

If I were you I would just bleed it now, with what is in it , adding just bog standard water to top up , bleed it , run it and make sure your problems are only air before spending time and money flushing and refilling with coolant mix, it’s a big system 17l so you need 6 litres of antifreeze for totally empty system ( in reality it will never be completely emptied so a gallon will do )

Make sure you have the heater controls set to hot before you start bleeding