robmar Posted May 23, 2007 Share Posted May 23, 2007 I had to replace my thermostat recently as it was sticking on, and I saw a couple of times very high temperatures (115 plus) before I could should it down and let it cool down. Since then I have fitted a new thermostat using the QED top hose kit... however now what I expereince is that after a run I get coolant coming out of the header tank ☹️ this is only sometimes ❗, and it is only after I have shut the engine off whilst running see normal temperatures between 79-83 degrees, coolant isn't gunged up and I don't get white smoke from exhaust (more than usual) on start up this is on a mildly modded 1600K so is it HGF or an airlock or something else 🤔 rob - who has his fingers crossed.... Link to comment Share on other sites More sharing options...
Mark Durrant Posted May 23, 2007 Share Posted May 23, 2007 Rob I suspect the pressure cap on the header tank is at fault so change this first and see what happens as they are a known weakspot Mark D Comp Sec Link to comment Share on other sites More sharing options...
robmar Posted May 23, 2007 Author Share Posted May 23, 2007 forgot to add that this has been replaced too ☹️ Link to comment Share on other sites More sharing options...
Jason Plato Posted May 23, 2007 Share Posted May 23, 2007 looks like Its gonna have to come apart Rob ☹️ ☹️ here is C7 TOP Taffia Area Rep Link to comment Share on other sites More sharing options...
robmar Posted May 23, 2007 Author Share Posted May 23, 2007 bummer ☹️ Link to comment Share on other sites More sharing options...
Sheds Moderator Posted May 23, 2007 Share Posted May 23, 2007 Early stages HGF ☹️ do it now and save the head from skimming. Link to comment Share on other sites More sharing options...
Rob Walker Posted May 23, 2007 Share Posted May 23, 2007 I would remove the QED remote stat ,refit the standard thermostat into the standard rover housing, check the whole syetem for leaks, bleed system and give it another run before pulling it apart. The coolant expansion is probably due to the system not pressurizing fully, if it were a HG fire ring then the coolant would expand and the system would be overpressurized after a few secs/minutes running. If the HG coolant seals had failed you should have either and external leak of coolant showing along the head /block joint or coolant in your oil or oil in your expansion bottle. Edited by - Rob Walker on 23 May 2007 09:52:53 Link to comment Share on other sites More sharing options...
robmar Posted May 23, 2007 Author Share Posted May 23, 2007 cheers rob the main reason I put in the QED kit was easy of changing the thermostat, so might try just removing the stat from the system in total... other thing is I have NOT drilled any holes in the stat to aid bleeding, should I try this rob Link to comment Share on other sites More sharing options...
Peter Carmichael Posted May 23, 2007 Share Posted May 23, 2007 This is a side issue, but did you change the coolant after the overheating incident? You probably need to. Heat damages the coolant additives package (most OAT coolants aren't rated much past 110 degrees) and the coolant isn't protecting against corrosion properly afterwards. Link to comment Share on other sites More sharing options...
robmar Posted May 23, 2007 Author Share Posted May 23, 2007 PC - yep although I wouldn't say I didn't a thourough job in flushing it out...so there could be some small amount of older coolant in there, however it has had numerous cycles so what might be in there should be thourghly mixed with the new stuff (which was the same type) rob Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted May 23, 2007 Leadership Team Share Posted May 23, 2007 Rob, I've not done the top hose stat install but speaking to someone who has, it does need a bleed hole otherwise there can be issues. Stu. www.superse7ens.co.uk..........the rebuild 😬 Link to comment Share on other sites More sharing options...
robmar Posted May 23, 2007 Author Share Posted May 23, 2007 Yeah - Mark D told me had done this before i installed it, but I didn't do it, maybe that is the first thing to do, should be easy now :) Link to comment Share on other sites More sharing options...
robmar Posted May 25, 2007 Author Share Posted May 25, 2007 ok so drilled hole in stat, much easier removal now with the QED remote kit, in / out and drilled in 15 minutes so I refilled it, bled it , ran it and all seems ok, but as previously it was doing it only some of the time I am not 100% convinced yet lets hope it doesn't chuck up at MIRA tomorrow rob Link to comment Share on other sites More sharing options...
Rob Walker Posted May 25, 2007 Share Posted May 25, 2007 IMO most people are too quick to blame the HG everytime. I would add a couple of caps full of Redline water wetter to the coolant, bleed it again and see how you go. Link to comment Share on other sites More sharing options...
Peter T Posted May 25, 2007 Share Posted May 25, 2007 Hole in the stat for the QED conversion is definately needed, it allows a small amount of air to escape and helps bleeding the sytsem. R500 260 BHP Mango Madness Link to comment Share on other sites More sharing options...
robmar Posted May 25, 2007 Author Share Posted May 25, 2007 RW - hence my query in the beginning can you tell me what the WW will do, I have some kicking around somewhere PT - cheers rob Link to comment Share on other sites More sharing options...
CAB Posted May 27, 2007 Share Posted May 27, 2007 Rob I have just changed a couple of perished hoses on my 1.8SS. I initially drained it just using the drain plug on the radiator and refilled it with clean water to flush out old coolant. I then drained it again and whilst changing the hoses noticed that you get at about another 3/4 litre of old coolant out of the engine by undoing the heater hose that goes to the standard thermostat housing and main bottom hoses. I think this syphons out the coolant trapped in the heater (if you have one) plus anything before the thermostat. Jacking the car front to rear then side to side also got a little bit more out. I am confident that I got all the old coolant out as I put in exactly 5.1 Litres of new coolant. The capacity of the coolant system (with heater) is 5.1 Litres according to the manual. I also added a couple of bleed Ts to the heater circuit; one in the top heater hose (near to the heater as possible) and one in the other heater hose where it goes into the metal pipe connecting to the main top hose. I refilled using 5 litres of 4 Life engine coolant sold by Demon Tweeks and 0.1 Litres of Redline Water Wetter (front of car jacked up). I refilled it until it just came out of the radiator bleed screw, then put the bleed screw back in and added the rest of the coolant whilst squeezing the hoses. The 4 Life coolant changes from red to yellow if there is leak of combustion gas into the cooant circuit. I used the 4 Life coolant to give me some early warning if I ever suspect that the worst has happened to the head gasket. I then bled the system in the following way: I started the engine (car level) with the header tank cap off and ran it for about 1 minute whilst squeezing all the hoses and opening and closing the additional bleed Ts and radiator bleed screws alternately. I topped up the coolant to just above the max mark and then put he cap on. For the next couple of minutes as the engine warmed up I opened and closed the bleed Ts and the radiator bleed screw to expel any trapped air. I then let the engine fully warm up and pressurise with a bit of light throttle. When the thermostat opens (standard thermostat in my case) and with a bit of throttle I could see air bubbles coming back to the header tank. After the engine cooled down I sealed the bleed T cap threads with liquid PTFE sealant. I have done about 100 road miles and two lapping sessions of Castle Combe Circuit since and the level is bang on the mark. Luckily the coolant is still red at the moment (touch wood etc etc)..... You can also get a kit to test the vapour in the header tank to see if it contains combustion gasses, Burtons sell this kit in the tool section of their website. Hope this helps. CAB Link to comment Share on other sites More sharing options...
robmar Posted May 28, 2007 Author Share Posted May 28, 2007 CAb - thanks for the info well it ran fine at MIRA for the first 3 runs, then the final run i parked on the trailer and then about 30s/1 minute later it chucked some out the cap again ☹️ only difference with the first 3 runs and the final run was that the final run temp was showing 84 and the others 80-81, so in theory could the thermostats being oen or close have this effect *confused*personally i can't see how so it is going to be another thermostat and see if that makes any difference, and then no thermostat at all and see if that makes any difference... rob Link to comment Share on other sites More sharing options...
Simon.Rogers1 Posted May 28, 2007 Share Posted May 28, 2007 Yes Rob change the stat. Just picked up on this and didn't know you had troubles at MIRA. I had to change the stat that came with my QED kit imediately it was toast. Sticking closed and open. Put a Rover one into the QED assembly and all was fine. Link to comment Share on other sites More sharing options...
robmar Posted May 29, 2007 Author Share Posted May 29, 2007 was only after the last run so not a disaster... rob Link to comment Share on other sites More sharing options...
robmar Posted June 5, 2007 Author Share Posted June 5, 2007 after a chat with Oily he strongly suspects HGF so need to get hold of the kit to test for any combustion gases in the header tank, or radiator I looked at the burtons site but couldn't find what I was looking for, anyone know any other online stockists 🤔 Link to comment Share on other sites More sharing options...
Scared Was The Sheep Posted June 10, 2007 Share Posted June 10, 2007 Talking of these QED conversions! Last year while getting the head gasket sorted I had one of these installed and I'm not convinced that it's working correctly so though I'd ask the collective here!! When starting to heat up all seems fine, then it gets to about 80 and opens cooling everything down again. This seems to happen about 5 or so times then just stays open all the time so that the temperature gauge is showing just above the blue!! Is this OK or should I be doing something extra with this conversion? Link to comment Share on other sites More sharing options...
robmar Posted June 11, 2007 Author Share Posted June 11, 2007 Nick - that is pretty much what mine does, although prolonged idle will see it creep up Anyway I ran a block test using the kit CAB suggests and although the liquid didn't turn yellow (from blue) it did go a greenish/yellow which strongly suggest to me that it is HGF... rob ☹️ Link to comment Share on other sites More sharing options...
Simon.Rogers1 Posted June 11, 2007 Share Posted June 11, 2007 Nick I have the QED and 74 deg stat linked to a digital temp sensor. All warms up to 77 deg then the stat has opened and it sits at 75 deg unless standing still and I switch on my fan. Link to comment Share on other sites More sharing options...
Scared Was The Sheep Posted June 11, 2007 Share Posted June 11, 2007 I'm fairly sure that it's not HG failure this was put in after the HG was replaced, I'm just curious as to whether the temperature going up and down during warm up then sitting constantly just above cold on the temperature gauge was normal? On the surface it appears as though the stat is either closed or fully open and nothing in between!! Link to comment Share on other sites More sharing options...
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