Around 18 months ago I had coolant changed as part of a service at the dealers. I don't remember checking the coolant level after the service to see what level they gave it back to me with. But before the service I had the coolant level between min and max and it stayed between those two levels for the length I had it which was over 18 months. Now I just went to have a look under the hood and noticed that the coolant level is approx 1cm below the min mark. I will top it up back between the min and max again. I dont have any overheating issues nor do I see any coolant leaks. Is there a chance that they could have left it at minimum mark and over time it has dropped a little?
More likely that the garage left it on the maximum if they’d just changed.... could have developed a leak at any point between now and then, but if it’s only minor then it’ll not be the easiest to find. Sent from my iPhone using Tapatalk
I will top it up to just below the max line and make a small little mark to what level i fill it at and then see if it maintains that. Is the coolant level never supposed to drop? I understand it can rise when the temperature rises and when car is running but after it has cooled should it always go back to normal? so over 18 months it should not drop at all? If it still drops, am I correct in believing that the only two things that can cause coolant loss is either a leak or a head gasket issue? Whereas if a car is overheating on the other hand it can be much more than just a leak. If the level drops again after i top it up, I am assuming best thing to do is use those coolant system pressure testing kits to see if the system holds pressure. If it does not then means there is a leak. Do I pressurise the bottle where the coolant is filled into? and what kind of pressure to?
Correct in everything you’ve said above. I personally wouldn’t bother with the pressure test - the coolant system is under a reasonable pressure when the system is hot, so if you can’t detect a leak then, it’ll be no different when it’s cooled down and then pressurised externally. You can get some UV dye stuff that can be added and then it will leave a residue that can be seen under UV light. I believe this is how garages will tend to find minor leaks. It really all depends on how fast it is leaking. If it were me, I’d carry some spare antifreeze in the boot and keep using it - as you say, monitor the level after topping it up to a known mark. I think there is an electrical connection on the expansion bottle which will give you a warning light if the level drops to a more critical level than just the minimum mark on the side. Sent from my iPhone using Tapatalk
OK thanks will monitor it. BTW, does anyone know the procedure to bleed air from cooling system? From what I remember there are 2 bleed valves, one by thermostat and another at the back higher up. But I read somewhere that the user manual says not to open bleed valves when engine is on as this can damage the engine. If that is the case then when are you supposed to open the bleed valves to see if air comes out?
