Club 80-90 Forums

Hello

I tried to search the archives to no avail, hoping some one may be able to shed some light?!

I went to check coolant level in the expansion tank, and noticed the coolant looked a little dark. Checked the header tank and although full, the coolant was jet black.

It doesn't look or smell like oil, so hoping it's not a head gasket problem.

I've heard mixing some types of coolant can cause a change of colour?

Or could it just be gunge or dirt in the pipes or radiator?

Has anyone ever experienced this or would anyone have any ideas?

Many thanks

Matt

Engine type ?

Ian

Hi,

Sorry I forgot to mention the engine.

It's a 1.6D "CS"

Many Thanks

Matt

Right then, over to the heavy oil brigade with you

Ian

Not something I ever came across in the 8 years I had a CS, sorry.

Was it ever not black?

Some of those nasty "sealers" are black.

not had owt to do with t25 diesels. but on a diesel engine, normally it points to head gasket or oil cooler letting go. if it was a normal van set up id say flush it out a couple times and keep and eye on it.

mark

I haven't had the van long and remember the coolant in the expansion tank looking a little dark when I first checked it, but put that down to the tank being old and dirty on the outside. This is the first time I checked the header tank.

The van hasn't overheated to date (I hope I haven't jinxed it here!) and I presume that oil in there would cause it to go slightly yellow/cloudy?

I'll try bleeding the system. Can I flush the system with a hose once it's drained?? Would it be this simple?

Matt

you'll need this when you flushed it out

http://www.brick-yard.co.uk/forum/bleed ... 8d.html%7C" onclick="window.open(this.href);return false;

yes you can use a hose pipe to flush it out, im sure there was a how to in wiki. the page is now empty??? id separate into 3 bits (this is how I did mine) flush out the rad, the long pipes (front to back) and the engine. flush both ways. good luck with it.

mark

I've just cleaned out my tanks - with years of residue coating the insides the liquid looked black - did you extract a little coolant and look at it or did you just base the colour on trying to look through the plastic?

Thanks Mark - The page is really helpful! Also sounds like a good idea to separate things to flush like you did.

Oldiebut goodie, I unscrewed the coolant level sensor and then after seeing that had black liquid on and feeling a bit confused, I had to dip my finger in just to really see

Matt

Oil in the water = Baileys (beige cream) dependant upon just how much contamination there is....but not black.

The only time I've seen anything resembling black is 'silt' black deposits from the radiator, but it doesn't actually dye the water black. Then there are products such as Bars Leak that people add to the coolant to stop a leak....I'm wondering whether this 'blackness' is evidence of some such treatment?

Lack of sufficient coolant additive (antifreeze) can also cause some strange colours (antifreeze doesn't just stop the coolant from freezing) one of it's other jobs is to prevent internal corrosion). If there is insufficient antifreeze content the internal metals (within the engine block/radiator etc) corrode/depositing their 'oxides' in the coolant.

Steel blocked engines/alluminium head, tend to turn their coolant orange/brown 'RUST' but who's to say...

Martin

Could be as you say, no antifreeze and the formation of magnetite could cause blackness. I would be seriously worried about internal corrosion if that were the case.

When central heating systems rust, the water turns black. Start with a clean slate, drain and refill with correct coolant/antifreeze

Thanks for the help and advice from everyone.

I'm a little worried about internal corrosion. The antifreeze prevents corrosion but would it have much effect if corrosion has begun??? i.e could this be sorted without the need for a new engine and radiator if it turns out to be corrosion and it is bad?

I'm guessing that sieving the drained coolant and the water after flushing would show up if any bits of rust/corroded metal are floating about in the system?

I'll just have to cross my fingers!

Matt