tic Posted June 2, 2002 Share Posted June 2, 2002 Hi all, I have recently purchased a Roadsport A spec Caterham and am just starting to getting to know it. During an airfield day today, I got a problem where pressure in the water system blew a significant amount of water out of the filler cap. It was a normal session, with a normal cool down lap, and normal pit behaviour. I have never had this problem before, either on previous (harder) sessions or on previous trackdays. After this point the problem could be reproduced within two minutes under load from cool. I am a bit confused about this, does anybody have any thoughts or ideas where to start checking??? Cheers Tony Link to comment Share on other sites More sharing options...
Peter Carmichael Posted June 2, 2002 Share Posted June 2, 2002 Buy a new pressure cap from an MG-Rover dealer for 3.49UKP. Caterham seem to get hold of the rejects - the genuine tested article are marked with a white dot. If that doesn't fix it, then it is nasty Mr head gasket playing up, but this doesn't happen as often as people make out. Peterid=teal> 253 BHP K-seriesteeth.gif, no gearboxbum.gifid=red> Link to comment Share on other sites More sharing options...
EFA Posted June 3, 2002 Share Posted June 3, 2002 " but this doesn't happen as often as people make out" .......Except on your car..... new head gasket coincides nicely with the oil change schedule........ Fat Arn Visit the K2 RUM siteid=red> See the Lotus Seven Club 4 Counties Area Website hereid=green> Link to comment Share on other sites More sharing options...
Peter Carmichael Posted June 3, 2002 Share Posted June 3, 2002 Well at least I know my engine is fit and healthy and putting out the beans, 'cos I have started breaking gearboxes. Soon I will crack a bellhousing in my attempt to be just like Arnie... Peterid=teal> 253 BHP K-seriesteeth.gif, no gearboxbum.gifid=red> Link to comment Share on other sites More sharing options...
scooby dooby doo Posted June 3, 2002 Share Posted June 3, 2002 pressure cap does seem likely. its a cheap thing to try anyway. When you refil it make sure you use the correct coolant - you want a propylene glycol coolant - not the more common ethylene glycol stuff. Comma coldstream is such as coolant but most places will sell something similar. In case you're wondering the wrong stuff is corrosive to the alloy in the engine and can cause various nasty problems. Dave Hooper - North London dmch2@lineone.net Link to comment Share on other sites More sharing options...
Peter Carmichael Posted June 3, 2002 Share Posted June 3, 2002 Not directly corrosive, but cavitation erosion can be a problem This is when, just like a kettle prior to boiling a kettle starts making a load of noise, small areas of micro-boiling occur at the hottest parts of the compression ring on the head gasket. These bubbles get cooled by the bulk of fluid and they then collapse back to liquid. The surface tension of the liquid surrounding the bubble accelerates the rate of collapse causing a little hammer blow to anything nearby (the head) when the bubble finally collapse completely. The head is aluminium, and like all aluminium (a reactive metal) it is skinned with a layer of brittle aluminium oxide - the hammer blow knocks a hole in the aluminium oxide which floats away, leaving bare aluminium. The bare aluminium quickly reacts with available oxygen to form aluminium oxide, now forming a little pit, which reduces coolant flow and causes hot spots - repeat until failure. Propylene glycol (Comma Coldstream) mixed with water has good heat capacity and a very low surface tension. Redline Water Wetter also reduces surface tension to assist cooling and prevent cavitation damage and should be used with an antifreeze/water mix. Any antifreeze used with an aluminium engine should be an approved type which assures appropriateness. Ks seem to be more fussy and Comma Coldstream is good stuff. Peterid=teal> 253 BHP K-seriesteeth.gif, no gearboxbum.gifid=red> Link to comment Share on other sites More sharing options...
Gary G Posted June 3, 2002 Share Posted June 3, 2002 I presume that my 1600 Supersport has Comma Coldstream, since it was last serviced by Caterham Cars. Today, in ignorance of the info on this thread, I topped up the coolant with Castrol anti-freeze - unsure what type. Assuming this is the wrong type (ethylene rather than propylene) will it do any damage? When I say topped up, I mean 1/2 inch (50% anti-freeze, 50% water) in the coolant expansion bottle. C7 GAR id=red> Edited by - Gary G on 4 Jun 2002 00:37:53 Link to comment Share on other sites More sharing options...
Peter Carmichael Posted June 4, 2002 Share Posted June 4, 2002 Bad assumption - complete coolant replacement? a service item? I doubt it. Drain and change to Comma Coldstream being obsessive about getting airlocks out by raising the nose of the car "a lot" and squeezing and flexing all rubber hoses. Peterid=teal> 253 BHP K-seriesteeth.gif, no gearboxbum.gifid=red> Link to comment Share on other sites More sharing options...
rynicolson Posted June 5, 2002 Share Posted June 5, 2002 Gary C.... word from one who sadly knows... my local Caterham approved dealer used a standard 66/33 mix and after less than 2k miles the head gasket went as a result of air being sucked in through the header tank (knackered cap)... go for 100% comma Goldstream. Tricks Y57 CDS "Mutley" Link to comment Share on other sites More sharing options...
tic Posted June 6, 2002 Author Share Posted June 6, 2002 Geesh - Thanks all! Pressure cap ... first time my life will be that simple (I hope) Advice greatly appreciated - I think I would have got caught by one of the points (probably raising the nose to get the airlocks out ...) Cheers Tony Link to comment Share on other sites More sharing options...
John Vine Posted June 9, 2002 Share Posted June 9, 2002 Propylene glycol (Comma Coldstream) mixed with water I hate to nitpick, but what I think Mr C meant to say was "Propylene glycol mixed with water (Comma Coldstream)", as Coldstream is a ready-mixed coolant -- no need to add water. JV Ooops! Got my slashes mixed up! Edited by - John Vine on 9 Jun 2002 16:20:20 Link to comment Share on other sites More sharing options...
Peter Carmichael Posted June 9, 2002 Share Posted June 9, 2002 There are two Coldstreams, premixed and concentrate. Premixed is by far the most common. Peterid=teal> 253 BHP K-seriesteeth.gif, no gearboxbum.gifid=red> Link to comment Share on other sites More sharing options...
John Vine Posted June 10, 2002 Share Posted June 10, 2002 Hmmm..., I just knew it would be unwise to challenge PC! But, as ever, I've learnt something, as I didn't even know there was a concentrate version. (As they say, when you stop learning, you're dead.) JV Link to comment Share on other sites More sharing options...
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