Peter Duce Posted August 1, 2004 Share Posted August 1, 2004 I have just done 750 miles on the new engine. Been running fine since first scare of expaonsion tank filling - after subsequent bleeding - phew. Everything that could be replaced has ... However still having problem. Is it normal to have air bubbes and fluid passing back from the engine to top of the expansion tank when you blip the throttle. Not sure if this is just air in system or there a more funcemental problem .... Peter Link to comment Share on other sites More sharing options...
Bob Corb Posted August 1, 2004 Share Posted August 1, 2004 A small flow into the header tank is nothing to worry about. This flow is there to remove air/vapour from the system. Do the bubbles appear due to the splashing or is there are large quantity of gas being chucked into the tank? You shouldn't really be able to see the small amounts of air coming though. As long as theres no substantial amount of froth being drawn into the pump you'll be fine. Bob Link to comment Share on other sites More sharing options...
Dave Barrow Posted August 3, 2004 Share Posted August 3, 2004 I had the same when I had it pressure bled the mechanic not a 7 exp one tho good was convinced gasket on way out as he saw the same symptons how ever a quick chat with Len of freestyle revealed the cause and logically explained why perfectly normal and would not build up air in the system. Dave B Superlight No.175 Freestyle superwide Pushrod SV rear and aerofoil mmmmmmmm! Link to comment Share on other sites More sharing options...
Peter Duce Posted August 3, 2004 Author Share Posted August 3, 2004 Thanks Guys Peter C helped me make sure system was bled properly on Sunday - and a quick test revealed all ok. I am out of the country at the moment, returning tonight where I hope to renew my running-in process. I was just being paranoid .....I think 😬 Link to comment Share on other sites More sharing options...
Peter Duce Posted August 5, 2004 Author Share Posted August 5, 2004 Well maybe not as paranoid as I thought .... came to work yesterday and it was ok (20 miles) - after returning early afternoon expanison tank nearly full. So I have an issue - looked this morning and no difference in level. Peter C bled system so I am certain there is no air trapped (and I have bled it many times before and never had this problem). It is either the head is porous (even after Ultrasealing) or somehthing we have not looked at! The bottom end is now a scholar block - so should be bullet proof. It can only be the head surely. I want to check the water for exhaust gases - anyone know where to get the "test" kit? Rover parts have never heard of it. Link to comment Share on other sites More sharing options...
TomB Posted August 5, 2004 Share Posted August 5, 2004 Is this thread on my problems helpful? here Link to comment Share on other sites More sharing options...
Rob Walker Posted August 5, 2004 Share Posted August 5, 2004 If the level is rising significatley in the expansion tank then this indicates that the cooling system is not sealed . Could be you have a duff pressure cap on the expansion bottle or a loose hose. With the system sealed the pressure build up prevents the coolant boiling in the hot spots like above the exhaust valves. Link to comment Share on other sites More sharing options...
Peter Duce Posted August 5, 2004 Author Share Posted August 5, 2004 Tom After talking to many people it is difficult to imagine how air can get in, without water leaking out, unless it is boiling somewhere. So before I take any drastic action i am going to bleed the system again. Lower the level of the water in the expansion tank slightly, add a new radiator cap and see if there is any change. The next time after a short drive. Had already read your link and was considering adding that it sounded like HG failure. I have had the HG replaced twice (new Scholar block 2nd time) and the symptoms are similar to mine and Nick Woods. I hope I am wrong. Link to comment Share on other sites More sharing options...
TomB Posted August 5, 2004 Share Posted August 5, 2004 I had my coolant tested for hydrocarbons - negative result. A block test was done which was inconclsive- no signicant pressure drops. I suspect the HG may have failed but at the moment is a small failure that only appears after a longish fast run or the engine is very hot. I think I am going to leave it for the moment & keep an eye on it, then replace it come the dark nights later in the year. Link to comment Share on other sites More sharing options...
Jason Plato Posted August 6, 2004 Share Posted August 6, 2004 Have you replaced the cap during all your troubles ? This is the most likley culprit , which is why I am about to provide a new ally tank and quality pressure release cap . Dave Link to comment Share on other sites More sharing options...
TomB Posted August 6, 2004 Share Posted August 6, 2004 Yes Dave, Ive replaced the cap. Does it need changing when water is expelled? I apologise for sounding ignorant, but hnow will a new ali tank & different cap help? Apart from looking nice? Are the normal caps bought from PArtco or Rover poor quality? Link to comment Share on other sites More sharing options...
Jason Plato Posted August 6, 2004 Share Posted August 6, 2004 If your cap is releasing coolant then it is either dud or you are pressurising the sytem . The Rover caps are only a few ££ and this would always be my first line of replacement . The original rover caps are crap , to the extent that rover dealers are now testing each and every cap before seeling them to a customer The ally tank itself wont help the problem - that will only look nice , but the benifit will be that the fitment for the pressure relief cap can be of the conventional 90degree twist type . Uprated pressure relief caps and high quality caps such as those made by a company such as Stant can then be used in place of the crap Rover caps . Dave Lotus 7 Club Speed Champion 2003 South Wales Area Organiser C7 TOPhere Link to comment Share on other sites More sharing options...
Nick Woods Posted August 6, 2004 Share Posted August 6, 2004 Hi Peter - YHM Nick Red and Black 1.6K supersport visit Carrotland.co.uk Link to comment Share on other sites More sharing options...
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