Coolant

[Tony de Wonderful]

Checked my coolant this morning in the reservior, noticed it has gone down to just past the 'min' level and is discoloured brown.

I had my mech flush and clean out the radiator about 4000 km ago (back in September). Also did water pump.

I'm taking it in for a service in a week anyway.

Just wondered if I need to top it back up for just a week?

I understand that the level shoudn't go down and that this is a sign of a leak, also the brownish colour could be anything from contamination by oil (due to leaking gasket or *gasp* a failing cylinder?), to just corrosion?

If it is corrosion then how is it happening after the radiator was cleaned out and new coolant put in? Or is that normal with a cleaned out radiator?!

[mad082]

i think it can also happen if it has overheated.

[Tony de Wonderful]

i think it can also happen if it has overheated.

Car hasn't been tracked or dragged, have never seen the temp sensor go more than half-way.

Don't give the car much of a thrashing. Occasionally give it WOT but only up to the speed limit.

Stock boost BTW, but has FMIC.

Edited January 19, 2010 by Tony de Wonderful

[mad082]

the problem with the stock gauge is that it sits at normal from around 70 or 75 degrees all the way up to around 100 or 105 degrees. and then it will suddenly jump up from there.

and a car doesn't have to be tracked or dragged to run hot. often they can get hotter sitting in traffic than out on a track where there is plenty of air flowing through the radiator.

it could also be that you have done a headgasket, as oil in the water or water in the oil doesn't always occur. but best to speak to your mechanic about it.

just a thought, but was the coolant that he put in green? i have seen some redish coloured coolants before (i think repco do one) so if you hadn't taken any notice of the colour until now it may be that he just used a different colour coolant and there is no problem at all

[Tony de Wonderful]

the problem with the stock gauge is that it sits at normal from around 70 or 75 degrees all the way up to around 100 or 105 degrees. and then it will suddenly jump up from there.

and a car doesn't have to be tracked or dragged to run hot. often they can get hotter sitting in traffic than out on a track where there is plenty of air flowing through the radiator.

it could also be that you have done a headgasket, as oil in the water or water in the oil doesn't always occur. but best to speak to your mechanic about it.

just a thought, but was the coolant that he put in green? i have seen some redish coloured coolants before (i think repco do one) so if you hadn't taken any notice of the colour until now it may be that he just used a different colour coolant and there is no problem at all

I think the coolant was green.

Engine still seems to run smooth and not aware of any smoke etc from 'zaust.

I took the cap off the radiator and the coolant residue inside seems fairly 'clean'. Coolant was not sitting flush to the top of the radiator...is it supposed to? Oil level seemed ok also, no sign of gung or stuff on the dipstick except 'normal' engine oil.

I noticed on my reserviour there is a kind of 'vent' on top (see pixxor)? Is it possible that it (the coolant) just evaporated away and left behind a bit of concentrated gung at the bottom of the reservoir?

Edited January 20, 2010 by Tony de Wonderful

[mad082]

would be unusual for so much to evaporate in such a short time.

[Tony de Wonderful]

would be unusual for so much to evaporate in such a short time.

Yeah I agree, but then it is kind of hot in this country.

[Godzilla32]

You won't loose that much coolant. It should barely drop in the overflow bottle. Most likely a leak, internal or external.

[shaund]

In my experience, alot of coolants will go brown if they have been exposed to air.

When your mechanic did the coolant, did he bleed the air out of the system with the bleed bolt on the drivers side top front of the motor? its near the front of the fuel rail and has a sticker around it with some jap writing on it. At least thats how it is on the RB26.

[Tony de Wonderful]

I opened the radiator cap and it took about two cups of water to fill it up. When I opened it up next day the level had gone down a little, so I figure there is a tiny leak some place.

Spoke to my mechanic and gonna bring it in next week. In the mean time he said just keep an eye on the water level and be careful.

[GTR-N1]

Q. And what do the words ^^^ "be careful" mean?

A. As mad082 said in post #4, the temp can all of a sudden, race up to the red. Watch the gauge like a hawk. Personally I wouldn't drive it now if there are spare wheels hanging around.

[Tony de Wonderful]

Q. And what do the words ^^^ "be careful" mean?

A. As mad082 said in post #4, the temp can all of a sudden, race up to the red. Watch the gauge like a hawk. Personally I wouldn't drive it now if there are spare wheels hanging around.

Well I am making sure it is full before I drive the car. If it has a very tiny leak, is it likely to catastropically turn into a bigger one just like that? I mean any engine could suffer a complete loss of coolant I think?

Yeah need the car for work.

Edited January 22, 2010 by Tony de Wonderful

[mad082]

depends on what is causing the leak. if it is in the radiator core itself then it may not get worse at all or it could let go and dump all the coolant in a matter of seconds.

if it is in the head then the same applies. i have seen some pretty big holes in water galleries in the past. my aunty in law had a festiva with a hole the size of a golf ball.

[Tony de Wonderful]

Well I took it to the shop and they checked it for leaks...with the result that they could not find any.

Mech reckons there may have been an air bubble or something from when the coolant was last changed.

Level seems stable now but keeping an eye on it.

[NA_Goodness]

Which mechanic did you take it to? I've bled my car up 3 times in 9 months (Dont ask!! Lol) and every time managed to get every drop of air out. Shouldnt be too hard...

Edited January 31, 2010 by NA_Goodness

[Tony de Wonderful]

Which mechanic did you take it to? I've bled my car up 3 times in 9 months (Dont ask!! Lol) and every time managed to get every drop of air out. Shouldnt be too hard...

Probably shouldn't say, but I am assuming they used one of their junior guys to do it. No harm done really.

[NA_Goodness]

Understandable. Stick with the known and highly recommended mechanics like Ovaboost, Hyperdrive, AllStar, C-Red, XSpeed, ect ect.

And not all "junior guys" are bad. I'm a 3rd year apprentice mechanic myself

[lot843]

have u check the radiator maybe its rusty inside

[Altia_R34]

try using radiator flush

[iseekool]

From my experience - it takes half a week to fully "burp" the system of air.

1 Drain the radiator.

2 Fill it up to the brim.

3 Fill up the over flow bottle to just over the max level marking.

4 Drive the car like normal - DO NOT give the engine a hard time - take it easy.

5 Let engine cool (I usually wait till next morning).

6 You will notice the coolant levels in the over flow reservoir drop quite considerably.

7 Open radiator cap - GENTLY SQUEEZE the lower radiator hose and then the top radiator hose - you will notice quite alot of bubbles coming out - the radiator level will then go lower - this is normal.

8 Fill radiator to the brim.

9 Fill up the over flow bottle to the max level marking.

10 Repeat steps 4 to 9 daily until the coolant level in radiator and overflow reservoir stop going lower (For me it took 4 days).

TIP: Keep a bottle of fresh coolant in your boot for 1 week after changing your coolant - this is so that you can top up where ever you are.