Low coolant after hard drive

[Long]

Hi,

so i've been testing my 1997 2.5 TD bongo after overheating issues. I changed the thermostat and it seems to be running fine now. after many casual test drives there didn't seem to be any problems.

I tried to give it a hard drive so i did... going up hills, rev to 3000 while driving. and now when i look at the coolant when cold (after over night) the coolant in the tank has gone slightly below the low line. usually when cold it sits a 1-2CM above the low line.

is there a leak??? it hasn't over heated and i check engine and coolant temps.. all seem normal. running at 92c-95c and coolant flowing (bottom hose gets hot )

should i open the cap when cold and add coolant to bring back up to level? or should i leave it as it hasn't over heated..

when the car is operating temp and running the level is 1-2 cm below full line.

Thanks

[g8dhe]

Well your certainly going to need to fill it back up to the right level!
As to why it reduced in level either there was still a bit of air to come out, or there is a leak. If it was remaining air then it won't go back down again. If its a leak then it will show up in due course, but given you have the alarm you will be warned in plenty of time.

[Dogran]

I'm no expert but if its below the 'low' line then I think it needs topping up! I always make sure the coolant level in my Bongo is near to the 'max' line (with the engine cold).

If you don't know what type of anti-freeze you have in your Bongo I'd suggest either topping it up with water or using something like Prestone Universal Anti-freeze which can mix with any type of anti-freeze without issue. You can get it in Tescos. If you mix the wrong types of anti-freeze together it can cause problems.

[haydn callow]

You need to top up with a 50/50 coolant mix of the same type as you already have in there.
When cold, top up to the FULL line.
When warmed up it will be a centimetre or so above that line due to expansion.
If you carnt see the level due to a murky tank....When cold....take the cap off the tank and ' dip' the tank vertically with a dry stick....it should show about 1.5 centimetres of coolant on the stick..
Consider fitting a Low Coolant Alarm and you will be forewarned in future should the level drop....
If it continues dropping...find out why.

[Long]

Okay, got it.

will fill up to full when cold.

before when i did this when hot it would rise and become 3-5 cm above full line but perhaps it was because the thermostat was not opening and over heating it. Now that i have changed to new thermostat will see what happens..

Thanks

[cmm303]

It will rise when hot, but not so much it releases through small black pipe by the cap. If this cap is still original then worth replacing it.

I'd suggest that normal (gentle driving) running temp should ideally be in 80s (depends where temp measured though) so there may further improvements possible with cooling system but being confident about no coolant loss is top priority.