Volkswagen Golf III (1992 - 1997) - 97 2.8 Flushing / cleaning coolant system

Honest John Back Room » Technical matters
What do you think of Elon Musk? Have your say | No thanks
View Threaded
Wed 13 Jan 2010 18:47
97 2.8 Flushing / cleaning coolant system - VR6
Since I bought my car about 6 years ago, the coolant has been a sort of brown colour, instead of pink. I've changed coolant lots of times, flushed it a number of times with water / flush until it all runs clear, but the brown colour always comes back.

A brown substance coats the inside of the header tank too, which can be removed with a bottle brush, and I think all the pipes are also coated on the inside.

I want to sort it once and for all. I am going to take off all the pipes, and use a bottle brush to clean them - but what about the radiator? What can i do with that - can it be cleaned internally with some sort of chemical?

TIA

Reply | Report as offensive | Link
Wed 13 Jan 2010 20:22
97 2.8 Flushing / cleaning coolant system - Peter.N.
How much antifreeze are you putting in? To stop corrosion in the system you really need about 50%
Reply | Report as offensive | Link
Wed 13 Jan 2010 21:10
97 2.8 Flushing / cleaning coolant system - VR6
I have been putting in the correct concentration of coolant when I have flushed and refilled. It has also been checked at service, with no issues.
I have a feeling whatever the brown stuff is, is in the radiator.
Reply | Report as offensive | Link
Wed 13 Jan 2010 21:35
97 2.8 Flushing / cleaning coolant system - Victorbox
Try some Forte Cooling System Flush. www.autokits.co.uk/forte-cooling-system-flush-p-46...l
Reply | Report as offensive | Link
Wed 13 Jan 2010 22:24
97 2.8 Flushing / cleaning coolant system - dimdip
What colour coolant did it originally have? Apparently the blue G11 is not mixable with the red G12 so it has to be thoroughly flushed and rinsed when switching. The latest purple G12+ does not have issues if mixed with the earlier types.

How is the cabin heating? Wondering whether the heater matrix might be on the turn; hazy memory of someone saying the coolant went brown before it went...
Reply | Report as offensive | Link
Thu 14 Jan 2010 11:57
97 2.8 Flushing / cleaning coolant system - VR6
I'm not sure what the original coolant was, but I imagine it was G12 (pink), and the previous owner has put in some non-compatible stuff, or allowed corrosion due to weak concentration.

Cabin heating is fine, and has been for the last 6 years (my ownership), and the brown coolant has always been there.

Its not sludgy, just brown. Its stays pink for a little while after changing, but ends up brown. I had a new engine about 50k miles ago, so i think most of the 'brown stuff' is in the radiator.
Reply | Report as offensive | Link

Our honest used car pricing is a little bit different to all the others. You can get to our values through make or model - you don’t have to follow a prescribed route. Plus, it’s live, which means we can react to changes in the market quicker than any printed price guide.

Honest Used Car Prices

From which small car to buy at which price point to the best UK-built cars, our Top 10s have the lot. Click now for your shortlist.

Unsure of what to buy? Our Top 10s are here to help you....