CtrMint Posted January 2 Share Posted January 2 (edited) Happy New Year All, My New Year hasn't started too well, with my 620R suffering a failed radiator. That's a total of 4 failed rads when factoring those on my 420R, at least its the first on my 620R. I intend to replace the radiator with a Radtec unit as I know many owners speak very highly of their products. I've also noticed the following advisory on the Radtec website about coolant being a potential cause for the regular failures. https://www.radtec.co.uk/news/index/coolant-advisory Taking onboard the advise for the rad is one thing mind, I'm wondering if such coolant is compatible with the Ford Duratec and other parts Caterham fit, even say the submarine temp housing for example. Googling "blue glycol" seems a bit of a minefield too as most web based documentation on coolants focus on OAT/HOAT/IAT/ and so forth. Has anyone else made the switch, what your experience been like? Also can anyone provide greater knowledge with respect to "blue glycol". Thanks For those interested I've covered the matter in my latest blog post https://www.caterham7diaries.com/post/happy-new-leak Edited January 2 by CtrMint 1 Link to comment Share on other sites More sharing options...
Area Representative DerekH Posted January 2 Area Representative Share Posted January 2 Based on the advice from Radtec I changed to old fashioned blue coolant last year. No issues so far on my Sigma. You do need to change it every two years. DerekH Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted January 2 Member Share Posted January 2 (edited) My personal summary and conclusions, all of the following is in the archives somewhere: Colour of coolant isn't an infallible description of content. It's now pretty consistent but exceptions do pop up. I'm not convinced that OAT coolants are responsible for those failures in aluminium radiators. Radtec's advisory note does mention the risk of leaving engines unused. We don't know if the coolant had been left unchanged. And most of the affected Sevens will have been filled with the recommended OAT so it isn't surprising that that's what in them: this doesn't have to be causative. Following discussion in the archives we have lots of examples of excess load on radiators from mounts and hoses. Whenever anyone brings this up it is now helpfully followed by responses on how to relieve this: adjusting mounts, packing with washers, fettling hoses etc. That leaves the owner of an at-risk Seven with using a coolant recommended by the engine manufacturer and Caterham or one recommended by Radtec. Engines are more expensive and I'd choose the former. With the recommended frequency of change. Jonathan Edited January 2 by Jonathan Kay Link to comment Share on other sites More sharing options...
DirtBuddha Posted January 2 Share Posted January 2 (edited) 7 minutes ago, Jonathan Kay said: My personal summary and conclusions, all of the following is in the archives somewhere: Colour of coolant isn't an infallible description of content. It's now pretty consistent but exceptions do pop up. I'm not convinced that OAT coolants are responsible for those failures in aluminium radiators. Radtec's advisory note does mention the risk of leaving engines unused. We don't know if the coolant had been left unchanged. And most of the affected Sevens will have been filled with the recommended OAT so it isn't surprising that that's what in them: this doesn't have to be causative. Following discussion in the archives we have lots of examples of excess load on radiators from mounts and hoses. Whenever anyone brings this up it is now helpfully followed by responses on how to relieve this: adjusting mounts, packing with washers, fettling hoses etc. That leaves the owner of an at-risk Seven with using a coolant recommended by the engine manufacturer and Caterham or one recommended by Radtec. Engines are more expensive and I'd choose the former. With the recommended frequency of change. Jonathan Yes but... if blue (glycol) coolant meets the engine manufacturer's specs then there's no difference in its cooling properties to OAT, or any risk of damage, surely? So the question is whether bluecol meets the required spec? . Edited January 2 by DirtBuddha Link to comment Share on other sites More sharing options...
BigCol Posted January 2 Share Posted January 2 Stuart at Premier Power recommended blue coolant in my Sigma and I use Comma Xtream G48. No issues to date. Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted January 2 Member Share Posted January 2 The specification in the 2021 Owner's Handbook is: Coolant: MOTUL Inugel Optimal Anti-freeze The anti-freeze content of the coolant must be maintained all the year round. Caterham use Millers Alpine Red and Ford Superplus premium (ready mixed), however, if a water/anti-freeze mix is substituted for any reason a minimum of 50% anti- freeze is required. To ensure that its anti-corrosion properties are retained, the anti-freeze content should be checked by Caterham once a year. The coolant should be completely renewed every four years. WARNING! • DO NOT use anti-freeze to any specification other than that recommended (see technical data: recommended fluid specification). • DO NOT add rust inhibitors or other additives to the coolant – these may not be compatible with the coolant or engine components. ........................... The recommended make has changed a few times, but TTBOMK has always been OAT for Duratecs. As noted above there may be components in a Seven that aren't used by Ford with Duratecs. Apart from aluminium radiators and possible staining of silicone hoses I haven't heard of any problems. Jonathan Link to comment Share on other sites More sharing options...
CtrMint Posted January 2 Author Share Posted January 2 Quote Following discussion in the archives we have lots of examples of excess load on radiators from mounts and hoses. Whenever anyone brings this up it is now helpfully followed by responses on how to relieve this: adjusting mounts, packing with washers, fettling hoses etc. Jonathan, I felt the same, certainly with the 420R as the rad top hose is super stiff and forced to an angle which it doesn't naturally sit at. I've subsequently redesigned the hose work on the 420R, inserting a silicon section to reduce vibration from the stiff hose and also modified the hangers, to further improve the suppression of vibration and overall stress. However this failure is on the 620R which already benefits from soft silicon hoses which are correctly routed without stress. I've also remove the failed radiator and it doesn't appear to be misaligned or under any undue pressure. Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted January 2 Member Share Posted January 2 14 minutes ago, BigCol said: Stuart at Premier Power recommended blue coolant in my Sigma... ... Thanks. It would be interesting to know why from someone who has seen the inside of so many. Jonathan Link to comment Share on other sites More sharing options...
Leadership Team Shortshift Posted January 2 Leadership Team Share Posted January 2 Just moved from red to blue at Stuart's recommendation whilst he was tending to the broken valve springs on my Duratec R500. But after so many years I was bored of it always being the same colour and wanted a visual under-bonnet freshening anyway. 😅 James Link to comment Share on other sites More sharing options...
ScottR400D Posted January 2 Share Posted January 2 (edited) I’ve never been a great believer in the rads being damaged because badly mounted. I’ve never seen any real evidence. I know several who have done everything to isolate the rads but they still fail. When I built my car back in 2015 the first three rads all failed almost straight away. I had one pressure tested and repaired by a race rad firm and it’s been fine since. And of course the hoses were designed to fit my car (they’ve been used on the 420R with the layer rad set up but they weren’t designed for it). I’ve always used the Comma Red coolant. Changed at 5 years old and it all came out looking like new. No sign of any damage to anything. Edited January 2 by ScottR400D Link to comment Share on other sites More sharing options...
Drumster Posted January 2 Share Posted January 2 I've used Comma G30 in my both of Radtecs since 2010 with no leaks, the first one only leaked because a Subaru Forester tried to mate with the front of my 7 in 2015. Link to comment Share on other sites More sharing options...
StevehS3 Posted January 2 Share Posted January 2 PP changed mine from pink OAT to blue. I think OAT is commonly used for our daily drivers because of its long life between changes and the cars are generally regularly used. It different with the 7. Ours can be stood over winter without running. Personally am more than happy to change the coolant every 2 years. It is cheap and I take the water from the cellar dehumidifier. Bluecol has excellent compatibility with [I think] all engines and can even be mixed with other coolants. Link to comment Share on other sites More sharing options...
7 wonders of the world Posted January 2 Share Posted January 2 G48 is a silicate coolant not ideal for long periods of inactivity.. OAT coolant is pretty inexpensive so what's the issue using the coolant the engine manufacturer reccomends...? Link to comment Share on other sites More sharing options...
StevehS3 Posted January 2 Share Posted January 2 This is the problem, along with potentially damaging hoses too. Link to comment Share on other sites More sharing options...
ScottR400D Posted January 2 Share Posted January 2 2 minutes ago, StevehS3 said: This is the problem, along with potentially damaging hoses too. My experience is entirely the opposite. Link to comment Share on other sites More sharing options...
StevehS3 Posted January 2 Share Posted January 2 I have never had a problem with OAT coolant and the standard CC rads. I have seen lots of reported (some very early) failures of Radtec rads used with OAT coolant. Do Radtec warrant their rads when used with OAT coolant? Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted January 2 Member Share Posted January 2 58 minutes ago, StevehS3 said: I have never had a problem with OAT coolant and the standard CC rads. I have seen lots of reported (some very early) failures of Radtec rads used with OAT coolant. Do Radtec warrant their rads when used with OAT coolant? I think that the statement in their advisory notice means that they do. Jonathan Link to comment Share on other sites More sharing options...
PeterM Posted January 2 Share Posted January 2 I fitted a Radtec after 3 CC Rad failures on my Sigma. The Radtec is a super looking product; I didnt know whether to put it on the mantelpiece or fit it! And after much 'undecided hovering' at the Halfords shelves opted for Halfords Blue NAP coolant, intent on changing it yearly. I decided on non OAT as I was also told by Radtec that they can/will rework a failed Radtec rad if an OAT coolant is not used. The engine runs a tad hotter, which is not a bad thing, and so far so good. But if anyone tells me Blue NAP is not the thing I could change it!! Link to comment Share on other sites More sharing options...
Area Representative Golf Juliet Tango Posted January 2 Area Representative Share Posted January 2 I wonder how long "considerable amounts of time" is? Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted January 2 Share Posted January 2 Just going by coolant colour can be problematic, as depending on manufacturer, it may be a completely different spec. The Ford red/orange coolant is to the WSS-M97B44-D Ford spec that Comma Red meets. Blue coolant is normally G48 as used in BMWs until their recent change to greenish HT-12 (not to be confused with other green coolants). G11 can also be blue and G12 can be red (Dex-Cool is also a pinky orange colour that can look red after use), but they aren’t the same chemistry. Some chemistries can gel when mixed with Dex-Cool. 1 Link to comment Share on other sites More sharing options...
John Vine Posted January 2 Share Posted January 2 1 hour ago, aerobod - near CYYC said: Just going by coolant colour can be problematic, as depending on manufacturer, it may be a completely different spec. The Ford red/orange coolant is to the WSS-M97B44-D Ford spec that Comma Red meets. Exactly. And WSS-M97B44-D specifies an OAT coolant: "The material defined by this specification is a coolant concentrate composed essentially of virgin monoethylene glycol and OAT corrosion inhibitors. When mixed 50/50 with water it shall be a satisfactory fluid for vehicle cooling systems that contain aluminum engine components, radiators and heater cores, ferrous metals and copper brass. This material is for initial fill and service fill." JV 1 Link to comment Share on other sites More sharing options...
GulfSeven Posted January 2 Share Posted January 2 Any further info on OAT damaging hoses? The silicone bottom hose on my 4-year old 310R has become porous and will need changing in the spring... Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted January 2 Member Share Posted January 2 6 minutes ago, GulfSeven said: Any further info on OAT damaging hoses? The silicone bottom hose on my 4-year old 310R has become porous and will need changing in the spring... Not to the best of my knowledge. And there's a a lot of us with that combination. IIRC we never tracked down the evidence that led to this suggestion. Jonathan Link to comment Share on other sites More sharing options...
7 wonders of the world Posted January 2 Share Posted January 2 I've not exprienced any issue with OAT using SFS or ASH silicone hoses. However I have seen evidence over the years of glycol causing partial restriction in multiple places within cooling systems. I find it interesting that Radtec are suggesting (unless I've misread this) that warranty repairs are dependant upon using glycol... Would they be happy to cover engine warranty to...? If you are considering a change please remember you will need to repeatedly flush the system as most modern engines do not offer an effective drain plug... And glycol and OAT are not compatible. Link to comment Share on other sites More sharing options...
R400svn Posted January 2 Share Posted January 2 After fitting a Radtec last year i changed from Oat pink to comma G48 as was easy to get hold off. Was fine for a while but i have had some black fine like sludge that collects around expansion tank just above the water line. Dont really know where it is from and if it is from changing over. Have contemplated going back to the Pink regardless as the car never sits for more than a few weeks Link to comment Share on other sites More sharing options...
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