PROBE2 Posted February 15, 2019 Share Posted February 15, 2019 HiFollowing a change to radtec radiator having a challenge getting K series Caterham cooling system operating properlyIssue is after 20 mins drive and once full revs applied coolant blows out of hoses around heater and traces around expansion cap. Hose from heater to water rail particularly hot, Otherwise all looks ok.- no symptoms or issues before radiator change- appears NO water in oil or oil in water - car runs up to temperature fine- radiator top and bottom hose get hot, doesn’t appear air lock- fan kicks in fineappears system is pressurised and not relieving and finding weakest point, maybe just need new expansion cap?welcome any thoughts/experiences pleasecheersPaul Link to comment Share on other sites More sharing options...
revilla Posted February 15, 2019 Share Posted February 15, 2019 Hi Paul,When I've seen these symptoms before it's always come down to the head gasket in the end.It may not be - but I think you need to be getting a "sniff test" for combustion gasses in the coolant. There are two completely different head gasket failures on a K - the elastomer beads that keep the oil and water apart (and keep the water in round the edge) can fail giving oil water mixing (which you don't appear to have) but the other, rather unrelated failure mode is a breach of the fire rings where the head seals onto the tops of the cylinder liners. In this case the symptoms are often pressurisation of the coolant when you give it full throttle and high revs (high cylinder pressures). The high pressure in the cylinder pushes gas out into the surrounding coolant. You won't see oil in the water or water in the oil with a fire ring problem.I know it seems odd that it came on after a radiator change. Could it just be getting that bit hotter with the new radiator and tipping it over into failure where before it was just on the right side of sealing properly?From a friend's experience, sniff tests can give false negatives and sometimes it has to have been doing this for a while before a sniff test picks up enough combustion products in the coolant to show a positive result.If it is breaching the fire rings, you will want to get an experienced eye to have a good look to see why, just changing the gasket could well just lead to another failure in short order if there's a problem with the head or liners.AndrewPS: Worth getting the pressure cap tested (or swap it for another one anyway, they're cheap). But if it's blowing around the heater joints that sounds like high presure rather than the cap opening at too low a pressure. Link to comment Share on other sites More sharing options...
nickh7 Posted February 15, 2019 Share Posted February 15, 2019 I think you need to rebleed the system, also did you rough up the inlet / outlet pipes on the rad with some emorary cloth ? This sorted the weep I had on the hoses plenty of things in the archives about bleeding a k series Link to comment Share on other sites More sharing options...
Wrightpayne Posted February 15, 2019 Share Posted February 15, 2019 I had the same scenario after the system was drained and it was an airlock due to me not filling the system as per the recommended approach. Coolant makes a sticky mess!!Ian Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted February 15, 2019 Leadership Team Share Posted February 15, 2019 Paul, do you have a hole drilled in the thermostat?Stu. Link to comment Share on other sites More sharing options...
PROBE2 Posted February 15, 2019 Author Share Posted February 15, 2019 Thanks Ian and Andrewi am going to give it one more go, bleed system, new cap, hole in thermostat (thanks Stu, no hole at moment) and ensure valve on inlet clear. May also exclude heater for now to isolate that as an issue.if not I am due an engine upgrade so head off it is then!RegardsPaul Link to comment Share on other sites More sharing options...
revilla Posted February 16, 2019 Share Posted February 16, 2019 Paul I sent you a BM but your mailbox is full. Let me know when you've made some space and I'll send again. Link to comment Share on other sites More sharing options...
PROBE2 Posted February 16, 2019 Author Share Posted February 16, 2019 Thanks Andrew, space in mailbox now Link to comment Share on other sites More sharing options...
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