Rusty coolant - is it a problem?

[MGgeordie]

I have had my Mk1 Eunos for around 8 years now & every year I have to get the cooling system flushed out as the coolant goes a rusty colour. There is also rust sediment around the radiator cap & a fair bit of sediment comes out every time its flushed. I had the radiator recored when I first got it as I though it was that. I have always had antifreeze in it so it hasnt been run with just water in since I have had it.
The car has never overheated, I just have to flush it out & replace it due to the rust build up. When its replaced it goes a rusty colour again almost immediately.
Is this a problem? What long term issues am I going to have? Is the cooling system likely to fail because of this?

Or should I just stop worrying about it?

[Pablo Escobar]

I had this with my mk3 Golf, it was fine and in the 5 years I had it nothing bad ever happened. Having just aquired a mk1 mx5 I would be interested to hear if it affects them at all.

[vrsmxtb]

Radiators getting gunged up and blocked are pretty common, could be yours doesn't have it so bad as to cause any issues but does contaminate the coolant? Have you flushed the rad through until it runs clean?

[anonymous-user]

It could be that the car was run without antifreeze at some point and so there is a lot of rust buildup inside the engine and heater matrix (if you've had the rad re-cored that should be ok). You can flush and backflush the engine with a hosepipe until it runs clear and there are also commercial flushing products available. Personally I would just carry on as you are if it's not causing a problem. I've had this on sheddy cars in the past. If the heater works and it doesn't overheat then your annual coolant changes will get it all out eventually anyway.