Strange coolant issue
 

I have a very strange issue with the coolant on my XC90 (2007 3.2 petrol) which has suddenly changed from the normal blue/green colour to clear!

I last looked under the bonnet about 2 months ago and the coolant then was the correct colour, but when I went to check the oil etc today it has changed to a virtually clear colour, although it still smells and feels like normal coolant.

The car continues to drive great, with no overheating signs even in the extreme heat we have had this week and there are no warning messages displayed. The coolant level hasn't dropped or risen at all and the level / quality of the oil also look fine, with nothing untoward in the oil filler cap.

The car has a full main dealer / specialist service history and has always had the correct Volvo coolant. At the last specialist service in November the quality / freezing point of the coolant was checked and it was fine, not requiring replacement (although it has been in for a few years now and I was probably going to have it changed anyway at the next service).

Does anyone have any ideas why this has happened and could it be linked to the very hot weather we have been having?

Also does this mean the effectiveness of the coolant has now been compromised and should I therefore have the coolant changed asap?

Many thanks

Back in the 80s I remember buying a coolant for my MGB which changed colour as it became contaminated by the rust from the iron engine.
Not come across anything like that though for a very long time. I'd drop into your specialist and get them to have a look. A check should only take a few minutes.

Thanks for the reply and I think I will book it in for the specialist to have a proper look at.

If the coolant colour had darkened, or become brown etc I could understand what was happening, but the colour now is clear with a slight amber tint, so I cant think of how this would happen.

Its almost like the dye in the coolant has failed?

https://www.swedespeed.com/threads/c...-in-it.452329/

See post 20 and 21 on the attached thread

Cheers

Dave

Thanks Dave,

Thats really helpful and also reassuring, although I still have no idea what actually caused the coolant to lose its colour.

Cheers

Simon

Just to close off this thread, I ending up taking the car to my usual specialist (Independent Volvo Services in Letchworth - highly recommended) who confirmed that there were no issues with the cooling system or the coolant.

They have seen this colour loss before and advised that it does not impact the perormance of the coolant, but I couldnt stand having the wrong colour coolant in the car and asked them to change it anyway :icon_smile_lachuh:

that sounds like it was a batch of coolant from around 2013 which had that characteristic. coolant has two properties, anti freeze and anti corrosion. I would change it with volvo coolant and it will be fine for many years.