Adi Posted July 25, 2009 Share Posted July 25, 2009 hi all, problem: once the engine is nice and warm...all running fine...the kenlowe fan turns on/off according to temp when crawling in traffic or at a stop at idle....after around a minute of idling....the coolant mixture comes out(even tho fan is on) of the overflow pipe on the top of the expansion tank...after that the temp gauge rises frequently when driving and the fan remains on for a longer periods. once i get back home ...let the engine idle and cool down...open the expansion tank cap with little coolant right at the bottom...its almost empty...open the radiator cap and see the coolant is about 1/2inch below the cap. fil up as before....drive...stop idle a minute....expansion tank overflow at idle(with the kenlowe on). did a radiator flush...external cleaning....only difference is temp rises very slowly...but the above mentioned problem continues any ideas guys why?remedies? thanks Adi Quote Link to comment Share on other sites More sharing options...
western Posted July 25, 2009 Share Posted July 25, 2009 are you sure there is no air trapped in the system ? Quote Link to comment Share on other sites More sharing options...
markyboy Posted July 25, 2009 Share Posted July 25, 2009 hi all,problem: once the engine is nice and warm...all running fine...the kenlowe fan turns on/off according to temp when crawling in traffic or at a stop at idle....after around a minute of idling....the coolant mixture comes out(even tho fan is on) of the overflow pipe on the top of the expansion tank...after that the temp gauge rises frequently when driving and the fan remains on for a longer periods. once i get back home ...let the engine idle and cool down...open the expansion tank cap with little coolant right at the bottom...its almost empty...open the radiator cap and see the coolant is about 1/2inch below the cap. fil up as before....drive...stop idle a minute....expansion tank overflow at idle(with the kenlowe on). did a radiator flush...external cleaning....only difference is temp rises very slowly...but the above mentioned problem continues any ideas guys why?remedies? thanks Adi Hi Ady, You don't say what your engine is. Although that's not imperative it may help the diagnostics a little. Have you drained the system or worked on it before you started to get this problem? If so there could be an air lock. Does your heater get warm? A cold heater is one of the signs indicating an air lock in the system. If you haven't drained/worked on the cooling system then it's sounding like it may be a cylinder head gasket problem. HTH. Mark. Edit: Doh, Ralph beat me to it. lol. Quote Link to comment Share on other sites More sharing options...
Adi Posted July 25, 2009 Author Share Posted July 25, 2009 Hi Ady,You don't say what your engine is. Although that's not imperative it may help the diagnostics a little. Have you drained the system or worked on it before you started to get this problem? If so there could be an air lock. Does your heater get warm? A cold heater is one of the signs indicating an air lock in the system. If you haven't drained/worked on the cooling system then it's sounding like it may be a cylinder head gasket problem. HTH. Mark. Edit: Doh, Ralph beat me to it. lol. Mark its a 2.5NAD....well...i had this problem before but dint really pay attention...jus top up with coolant...frustrated me when i saw it happen as dad drove(i was in another car)...so did the radiator flush(ie put in the radiator flush chemical..run for 10 min...den drain with fresh water etc etc) problem existed....and now....checked the heater and its cold...as you say an air lock (had air locks in fuel sys a couple o months back and now here ) and Ralph as it implies i have an air lock. well guys how do i go about bleeding the bl#$@$ AIR from the cooling system? (damn air locks!!) Quote Link to comment Share on other sites More sharing options...
western Posted July 25, 2009 Share Posted July 25, 2009 take the heater hoses off either at the cylinder head or heater & fill one with water until you get water out of the other pipe/hose, then reconnect one, then fill up the 2nd & refit, top up the radiator & header tank & then refit the radiator cap & run the engine at idle for about 5 mins to give it time to pump the coolant around, hopefully this will purge any left over air from the system, switch off top up the header tank/refit cap & go for a road test, & then report back the rseults Quote Link to comment Share on other sites More sharing options...
Les Henson Posted July 25, 2009 Share Posted July 25, 2009 2.5N/A engine doesn't suffer from trapped air. Stuck closed thermostat would enable air to be trapped though by preventing circulation and may also be the cause of your problem. Other causes could be the water pump impellor heavily rusted which would reduce circulation. I don't suppose this initially started back when we had a really cold snap, did it? I did a few engines that has sheared the impellor shaft off, due to ice preventing it from spinning. No horrid noise or anything, and the water pump pulley turned ok. Les. Quote Link to comment Share on other sites More sharing options...
western Posted July 25, 2009 Share Posted July 25, 2009 I don't suppose this initially started back when we had a really cold snap, unlikely as Adi is in India not the UK Quote Link to comment Share on other sites More sharing options...
Adi Posted July 25, 2009 Author Share Posted July 25, 2009 take the heater hoses off either at the cylinder head or heater & fill one with water until you get water out of the other pipe/hose, then reconnect one, then fill up the 2nd & refit, top up the radiator & header tank & then refit the radiator cap & run the engine at idle for about 5 mins to give it time to pump the coolant around, hopefully this will purge any left over air from the system, switch off top up the header tank/refit cap & go for a road test, & then report back the rseults aye aye sir..done as u said sir....also...while idling saw the level of coolant rise in the radiator....shut the cap....then saw a gradual rise in level in exp/header tank....no overflows...went around for a road test...no significant drop in level in header tank...let the engine idle for a minute...switched it off. then started the engine again...looked all fine...after about 30 seconds of idle coolant coming out of the header tank overflow pipe:(. repeated the above procedure again....ie bleeding air from radiator...cap it...fil in header tank go for a drive...etc. overflow persists @Les no ice here am not in the himalayas yet Ralph, as Les suggests i guess i'll take a look at the thermostat...will remove it and try out 'boiling water test' wherein i put the thermostat in boiling water to see it operate. Any tips...dos n dont ...things i should look out for on the thermostat...? Quote Link to comment Share on other sites More sharing options...
Les Henson Posted July 25, 2009 Share Posted July 25, 2009 For the thermostat to cause the problem you have, it would have to be stuck closed, or partly so. If you put it in a pan of boiling water - you should see it open fairly quickly. You could of course remove the thermostat from the engine and then run it to see if the problem is still there. If not, then that's your problem. To ensure that you don't have an air block - drain the system, start the engine, then slowly fill it while it ticks over (do this with a cold engine). I know you are in a hot climate, but do you still use anti-freeze? Les. Quote Link to comment Share on other sites More sharing options...
Adi Posted July 26, 2009 Author Share Posted July 26, 2009 To ensure that you don't have an air block - drain the system, start the engine, then slowly fill it while it ticks over (do this with a cold engine). I know you are in a hot climate, but do you still use anti-freeze?Les. wil do the tickover bleed and report back. yes Les i use anti freeze....50-50 mix with water. Quote Link to comment Share on other sites More sharing options...
90_uae Posted July 27, 2009 Share Posted July 27, 2009 hi just would like you to keep space for air in the expansion tank other wise you making pressure ....just less than half of the tank will be good cheers ali Quote Link to comment Share on other sites More sharing options...
errol209 Posted July 27, 2009 Share Posted July 27, 2009 hi just would like you to keep space for air in the expansion tank other wise you making pressure ....just less than half of the tank will be good cheers ali As Ali says, the workshop manual says header tank should only be half full. Quote Link to comment Share on other sites More sharing options...
DaveSIIA Posted July 27, 2009 Share Posted July 27, 2009 Does the expansion tank cap seal correctly and open at the right pressure? It might be worth trying a known good one. Quote Link to comment Share on other sites More sharing options...
Adi Posted July 27, 2009 Author Share Posted July 27, 2009 Ali:- i fill the expansion tank half full. Does the expansion tank cap seal correctly and open at the right pressure? It might be worth trying a known good one. i guess the cap is good...have to press it down...n then twist and turn to open? i have narrowed down the overflowing, happens only when i start the engine...run it for some time...then stop...then start it...after its warmed up enough...that when about 0.5litre of coolant comes out of the overflow pipe on expansion tank. Quote Link to comment Share on other sites More sharing options...
Adi Posted July 28, 2009 Author Share Posted July 28, 2009 i replaced the expansion tank cap...problem solved Quote Link to comment Share on other sites More sharing options...
western Posted July 28, 2009 Share Posted July 28, 2009 well done & a fairly cheap fix. Quote Link to comment Share on other sites More sharing options...
Adi Posted July 29, 2009 Author Share Posted July 29, 2009 well done & a fairly cheap fix. thank you Ralph....and i learnt a good lesson...start troubleshooting with little things first Quote Link to comment Share on other sites More sharing options...
western Posted July 29, 2009 Share Posted July 29, 2009 we never stop learning, just put it down to experience Quote Link to comment Share on other sites More sharing options...
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