Support Team rob spencer Posted March 21, 2002 Support Team Share Posted March 21, 2002 Just completing my first build of a 1.8K Roadsport SV. Filled the cooling system.. expansion tank, then through top of radiator, then into heater inlet hoseStarted the engine last night (after some games with a loose fuel line). Released any air in the raiator by loosening the bleed screw in the top after about a minute (there was no air in it). After about five minutes the water in the expansion tank rose to the top of tank indicating that the water was boiling so I switched off straight away. The top hoses were hot. The top of the radiator was hot but the rest was only warm down to cold at the bottom. The bottom hoses were cold. The thermostat housing was hot with the hose attached to it cold. I immediately thought "the thermostat is not opening". Called caterham and they have said that it is not an uncommon problem that is usually down to air in the system. Apparently very little air is required to cause boiling. They suggested that I jack up the front of the car and bleed it again. Given the tone of the guy on the phone (and they are usually very helpful) I got the impression I was being treated like an idiot (I may be one but I don't like being treated like one) and am being fobbed off just to make sure that I had water in the system. Anyone had any similar experience or can reassure me in any way rob Link to comment Share on other sites More sharing options...
Jason Plato Posted March 21, 2002 Share Posted March 21, 2002 You should try and jack the front of the car up by about 2 feet , to get the rad bleed above all other areas - heater , expansion tank etc . Run the car up to temperature from cold with the bleed screw off , and gently squeeze all the hoses . Dave Link to comment Share on other sites More sharing options...
WILL FLY Posted March 21, 2002 Share Posted March 21, 2002 Rob How high in the air did you have the system when you tried bleeding it ? You need ideally to get the bleed screw on the radiator higher than the heater top hose. Did you have the heater knob pulled out ? If you still have the engine hoist then hang the front of the car from this, via the crucifix or top wishbones. Start the car with the bleed screw out of the radiator and only put it back in once the air is out. If the heater knob was in before then you may have air in the heater circuit. There are some photos of my cooling system being bled on my website. Roy See willfly.net for more info. If you don't spin you ain't trying smile.gif Edited by - will fly on 21 Mar 2002 12:45:02 Link to comment Share on other sites More sharing options...
David Hopkins Posted March 21, 2002 Share Posted March 21, 2002 I had exactly the same problem , if you want to give me a call I will explain exactly what I did to overcome this mobile 07785 287712 Link to comment Share on other sites More sharing options...
sjwb Posted March 21, 2002 Share Posted March 21, 2002 Rob, I suspect that the rise in level was due to an airbubble rising and not boiling water. It would have been advantageous to let the water vent - the level settle and then replenish with warm coolant. Continue to run until things calm down. Of course do keep an eye on the temp gauge. Steve B Link to comment Share on other sites More sharing options...
Mike Bees Posted March 21, 2002 Share Posted March 21, 2002 It's not uncommon for the 'stat to be reluctant to open when it's new. I've had this. Warm it up until it's close to 100deg. on the gauge (with the front raised, bleeding from the radiator screw etc.). Let it cool. Do it again. Repeat a few times, it should sort itself out. The tell-tale sign is the bottom hose getting warm. Don't let it boil. Mike Link to comment Share on other sites More sharing options...
Lennie Posted March 22, 2002 Share Posted March 22, 2002 The usual cause for this is the bottom hose where it goes into the thermostat housing. If you put the heater hose underneath the bottom rad hose you can get the the point where the rad hose goes upward and then down into the housing giving you an air bubble in the hose which means the thermostat does not get water and hence hot and open. If you jack the car up the air can go back up towards the rad and vent into the header tank but best way is to reroute the hoses so that the bottom hosegoes upwards towards the header tank naturally. Hope that makes sense if you look at the car its easy to see where the air is trappedIt's also a good idea when filling the car from empty to leave the cap off and not to fill the tank. Link to comment Share on other sites More sharing options...
Support Team rob spencer Posted March 25, 2002 Author Support Team Share Posted March 25, 2002 Drained and flushed the system (cos I'd put the wrong antifreeze in). Jacked the front of the car up about 18" and refilled. Started up and hey presto, the radiator got hot, the bottom hose got hot, and then the fan cut in at about 84C. No leaks showing (yet). Managed to finish the build ready for its post-build inspection at John Noble on Thursday. Thanks for the help guys(and your time David). rob Link to comment Share on other sites More sharing options...
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