a good way of checking coolant level (3sge na)?

[mr2_maverick]

Can someone please tell me how I should check the coolant level in my car? I read one post where it said the tube going into the expansion tank should be 5-7 inches wet from the bottom.

When my engine is hot the tube comes out half wet but when it's cold it comes out almost 4-5 inches. When cold sometimes the coolant sits right under the pressure cap and sometimes it's not visible at all.When the engine is hot obviously the coolant spills out. I don't understand this car, how am I meant to tell what the correct coolant level is?

I can't tell the coolant level just by looking at the expansion tank low and full marks.

[pbmr2]

expansion tank is just that, it has a level mark on it and it should be at that.
If it's too low then when the engine cools down it sucks in air not coolant.

The best way to tell on the cooling system is to use the 2 bleed hoses at the front from the heater and rad. remember to turn the heater slider to hot.

The filler cap should never be removed when the coolant is hot, as you depressureise the system and it busts out the fill hole. this lets air in and loses coolant.

When cold the coolant should be visible in the fill hole (not expansions tank hole, the pressure cap hole)

Might be worth checking the thermostat isn't sticking by changing it. Should be done every couple of years anyway.

[Dale_V]

its simple, lets not complicate things

1) ALWAYS check any part of the coolant system when its cold, not mildly warm, clap cold!

2) Remove the expansion tank plastic cap and check the tube, it should be wet with coolant about half way up ( 6" )

3) Remove the metal coolant cap, coolant will either be right at the top directly under the cap or it may require you to squeeze the hose that the coolant neck is attached to. Either way if good. aslong as you can see coolant, its fine.

4) Dont go messing about with the bleed hoses on the heater matrix or radiator unless you have an airlock

The reason you are getting different readings when the engine is hot compared to cold, is because when hot, the coolant is forced out of the system to the expansion bottle showing your 5-7"... then when its cold, its drawn back up into the coolant system via vacuum showing you the 4-5". Effectively it is doing what its supposed to do and seems to be working correctly.

[mr2_maverick]

[quote="pbmr2"]expansion tank is just that, it has a level mark on it and it should be at that.
If it's too low then when the engine cools down it sucks in air not coolant.

The best way to tell on the cooling system is to use the 2 bleed hoses at the front from the heater and rad. remember to turn the heater slider to hot.

The filler cap should never be removed when the coolant is hot, as you depressureise the system and it busts out the fill hole. this lets air in and loses coolant.

When cold the coolant should be visible in the fill hole (not expansions tank hole, the pressure cap hole)

Might be worth checking the thermostat isn't sticking by changing it. Should be done every couple of years anyway.[/quote]
I opened the pressure cap when engine was hot so now I would've sucked air into the system? My heater doesn't cycle between hot or cold, it stays hot and the car doesn't heat up or anything.

[mr2_maverick]

[quote="Dale_V"]its simple, lets not complicate things

1) ALWAYS check any part of the coolant system when its cold, not mildly warm, clap cold!

2) Remove the expansion tank plastic cap and check the tube, it should be wet with coolant about half way up ( 6" )

3) Remove the metal coolant cap, coolant will either be right at the top directly under the cap or it may require you to squeeze the hose that the coolant neck is attached to. Either way if good. aslong as you can see coolant, its fine.

4) Dont go messing about with the bleed hoses on the heater matrix or radiator unless you have an airlock

The reason you are getting different readings when the engine is hot compared to cold, is because when hot, the coolant is forced out of the system to the expansion bottle showing your 5-7"... then when its cold, its drawn back up into the coolant system via vacuum showing you the 4-5". Effectively it is doing what its supposed to do and seems to be working correctly.[/quote]

Ok I did this when cold and the fluid was 4-5 inches on the black tube that you dip into the expansion tank.

I could not see any water under the pressure cap when cold even after squeezing, I thought I was as losing water so I filled it with a bit of de-ionised water and it took about 75ml of refilling for the water to show up and sit right under the pressure cap. I read on mr2oc where some people said as long as it only takes about 100/200 ml to refill then your system is working ok. I've driven the car over a 1000 miles with no overheating issues and then another 20 miles last night after the refill with no issues. Next time should I just leave the water to be 4-5 inches on the black tube?

My expansion tank is so dirty I can't tell where the water is sitting even after shining light at it.

[Dale_V]

By removing the metal pressure cap when warm/hot, you're likely to have disturbed the vacuum, meaning that when you've put the cap back on it wont have been able to retrieve the coolant it pushed into the expansion when the engine was hot.

Top it up as you have done, and follow my above instructions from now on by checking when cold, 1000 miles in means all should be ok, i doubt you've drawn air into the system.

Keep an eye on the expansion tank tube (when cold) if the coolant level on that keeps rising after each time you take the car out, then there could be an air lock But as you've messed about with it/filled it up/disturbed vacuum you need the system to find its own level, so id say check the expansion tube level for about 5 cycles to check consistency, if it keeps rising and rising then you may need to re-bleed

[mr2_maverick]

[quote="Dale_V"]By removing the metal pressure cap when warm/hot, you're likely to have disturbed the vacuum, meaning that when you've put the cap back on it wont have been able to retrieve the coolant it pushed into the expansion when the engine was hot.

Top it up as you have done, and follow my above instructions from now on by checking when cold, 1000 miles in means all should be ok, i doubt you've drawn air into the system.

Keep an eye on the expansion tank tube (when cold) if the coolant level on that keeps rising after each time you take the car out, then there could be an air lock But as you've messed about with it/filled it up/disturbed vacuum you need the system to find its own level, so id say check the expansion tube level for about 5 cycles to check consistency, if it keeps rising and rising then you may need to re-bleed[/quote]

Okay what if the coolant level reduces in the expansion tank when engine is cold? Does that mean I'm losing water? It's really confusing because when I got the car, a completely cold system would show about 5-7 inches but when I checked it after those 1000 miles it seemed to show 4-5 inches. It never gives me a consistent reading. I checked it in between those 1000 miles too and it kept jumping up and down.