Radiator leak

[babymerc]

Just noticed water under rad on my 2016 270 sigma. Ran it up hoping it might be a hose clip, but no when up to temp it started steaming like a kettle.

Are these Ali radiators repairable or am I going to have to bite the bullet

[SteWi]

I had mine repaired earlier this year and seems fine since including three track days.  Mine was done by Berkshire Radiators.

Steve

[babymerc]

Thanks Steve, I'm in n.wales but nice to know it can be done

[ScottR400D]

Leaks are not unusual. When I built my car in 2015 the first 3 rads sent to me had leaks. I got one of them repaired and it's been fine since. I used a company in Bracknell who make race rads but anyone who assembles alloy radiators should be able to do the job,

[elie boone]

Most important is that it's mounted stress free, you may need a number of washers to fill up the gap between rad and rubber bobin. Even copper radiators can start to weep if there is to much tension in the rad when mounted.

[colindavies56]

N.wales radiator, garden city sealand. 

[babymerc]

Having taken my rad to North Wales Radiators, they informed me it was unrepairable . I am now the proud owner of a radtec radiator. After looking at several posts on here about various antifreeze to use, I phoned Darren at radtec. He informed me not to use oat antifreeze but use iat instead. Apparently oat doesn't like standing for any length of time. CC recommend oat. So consequently I'm totally confused. Any help gratefully received.

[ScottR400D]

I had 2 of my 3 leaky rads repaired back in 2015. One was fitted and has been fine since. Of course they’re repairable though I guess it depends where the leak is, mine were both on welds. Not sure you could repair a core. 

As far as I know, modern OAT is fine in alloy rads. There was a time when OAT coolant might damage some light metals (copper, zinc and therefore brass but it has developed to a point where it’s been safe in most if not all applications for years  

Again, as far as I know it’s also recommended by Ford for the Duratec and it’s main advantage is durability and long lasting corrosion prevention. For some time now OATs have been given a 5 year lifespan but some are now as much as ten years.  

My car has had the recommended OAT in since 2015. I changed it a week or so ago. The old stuff still looked fine and there was no sign of corrosion anywhere. Car’s never been run over winter so has stood around a bit during its time! 

I would suggest you forget what Darren told you, do your own research and try and find substantiated reasons not to use OAT. I haven’t been able to so far, in fact just the opposite. 

[babymerc]

Thanks for your reply. It was indeed leaking from the core. It does seem strange that a more advanced antifreeze (oat) would damage ali, but I'm not an expert

[Geoff Brown]

When Sigma rads had plastic header & footer tanks that was the real nightmare.

Mounting the rad with enough give to compensate for vibration is the issue. More especially with a 2.0L Duratec as they vibrate subtly with what can be a high harmonic.

As to OAT coolant - have it in my Duratec as recommended since built & changed once with no problems.  Five year old liquid was crystal clear as the day installed.