Blue antifreeze turned green

[Bob]

Bongo Pals...

[Northern Bongolow]

I'm pretty sure its normal for the blue stuff (ethylene glycol presumably) to turn green once diluted and heated in the cooling system. My lca is prone to the occasional murmour even after new screws were fitted. Suspect its viltage related

Prior to the cooling system transplant the LCA behaved impeccably, going quiet after its self test. My voltage isn't as good as it could be but has not caused any problems to date. Also this morning the LCA blipped when I switched the aircon on. May be the coolant change has highlighted an electrical problem that previously I was getting away with.

i think haydn may be able to comment on this but i think ive heard it that the lower antifreeze content is a better conductor than the 50-50 mix you may have now so this may slightly affect how the alarm works, especially after a cold start when the glow plugs are on and the aircon /heater/lights etc.

[cmm303]

I'm pretty sure its normal for the blue stuff (ethylene glycol presumably) to turn green once diluted and heated in the cooling system. My lca is prone to the occasional murmour even after new screws were fitted. Suspect its viltage related

Prior to the cooling system transplant the LCA behaved impeccably, going quiet after its self test. My voltage isn't as good as it could be but has not caused any problems to date. Also this morning the LCA blipped when I switched the aircon on. May be the coolant change has highlighted an electrical problem that previously I was getting away with.

i think haydn may be able to comment on this but i think ive heard it that the lower antifreeze content is a better conductor than the 50-50 mix you may have now so this may slightly affect how the alarm works, especially after a cold start when the glow plugs are on and the aircon /heater/lights etc.

it would perfectly explain the observations.

[cmm303]

PS. By "going off" I meant going silent.

That's a good thing surely?

Re: the antifreeze, as you've had so much 'disturbance' on the system with the new hoses, etc, I'd be tempted to run it for a week or so and then drain, flush and refill again with fresh anti-freeze just to get out any more muck and old coolant that may still be lurking. I used the blue Triple X stuff before and it stayed blue for the year or so it was in there.

took your advice and replaced all coolant again yesterday.

As an aside the LCA settled down as the week progressed. The only difference was that it didn't go silent afte it's self test but before starting the engine. I feel almost certainly voltage related with the new coolant having a higher resistance somewhere.

[cmm303]

There is that 'cain alternative' method in the factsheet about flushing with a hose and warm water.

thanks for the pointer. I refilled following a flush, not exactly as the Cain Alternative but inspired by.

• Starting all cold, engine off, I put my valve + jug on the bleed hose.
• Removed expansion tank cap and had garden hose constantly filling this up. This is NEVER allowed to drop below low.
• Ran water out of bleed hose to expel any air that might have got in when sorting out bleed pipe then shut it off.
• Opened bottom rad valve and flushed rad through, then closed.
• Opened bleed pipe valve and flushed through.
• Did a few bleeding shimmies to make sure.
• Started her up
• Changed the garden hose to hot water - took its time to run hot as long hose and flow required is quite slow. Worked out just fine.
• Carried on flush from expansion tank to bleed pipe.
• Occasional bleed see saws.
• Wondered if the flushing was stopping the stat opening so stopped and waited for engine right up to temp with bottom rad hose hot
• Started flushing and more bleeding shimmies needed as a lot of air was coming. Didn't I bleed it properly the previous week or is the flushing introducing it?
• All told, I reckon I flushed through about 12 buckets and it was still tinted. I'm was using the same coolant type but I'm not sure what you'd have to do if you were change between OAT antifreeze.
• Next step, add antifreeze. I didn't full grasp the Caine method. You have a full cooling system and need to add all that extra antifreeze but the coolant flowing out of the bleed pipe picks up fresh fluid being poured in quite quickly. Using concentrate really is best as there is less fluid to displace. Bongo holds13.5l coolant so have antifreeze for about 15-16l.
• I did this with the engine running.
• Everything was controlled through the bleed pipe valve.
• Lowered the level in the expansion as far as I dared.
• Filled up and carried on filling with antifreeze.
• Ditched the bleed pipe outflow until it started to look properly coloured. I had about 3l of concentrate to go at this point.
• Continued adding the concentrate but kept the drained fluid.

You end up with all the fresh antifreeze in the system and about 3l or so of saved drained hot stuff. At this point I recycled this through the system by adding back into the expansion tank and collecting out of the bleed pipe to ensure an even mix. On reflection I think I was being a bit dumb.
Anyway I've saved the hot stuff for topping up other cars of course because the bongo never needs topping up. And it is definitely BLUE this time, NO GREEN tinge!!
If my sums were right the resulting antifreeze concentration in the cooling system should be as near as dammit 50:50.

• Finished off with more bleeding shimmies which did seem very necessary though the level in the expansion tank never dropped below low.

If might seem a bit wasteful on antifreeze but cost wise it's a lot cheaper than paying a garage. A mate has just been quoted by a bongo garage £250+vat for a coolant change.