Ben Caswell Posted October 23, 2016 Report Share Posted October 23, 2016 When the fan belt broke on my car I was surprised how quick it overheated because the water pump had stopped. It could be the water pump is not working as well as it should ie corroded fins or the impeller has fallen off. Link to comment Share on other sites More sharing options...
dougbgt6 Posted October 23, 2016 Report Share Posted October 23, 2016 Agree with Ben, I recently had a head gasket blow on my GT6, it had previously never had an overheating problem, even in traffic. Inside the engine I found a very old head gasket, 30 years old, completely wrecked by the overheating. It may have been faulty before hand and caused the failure. However there was also a blockage in the water pump housing water way between the pump chamber and the head inlet. It's certainly worth flushing out the block and taking a look at the water pump and it's housing. Link to comment Share on other sites More sharing options...
hughestill Posted October 23, 2016 Author Report Share Posted October 23, 2016 what engine fan is currently fitted?? all our cars prefer good air movement under the bonnet when in traffic .idling etc, to keep the under bonnet ambient temp down. an engine fan does this where as electric comes on to what its set , the engine driven is pulling air all the time ...better there are changes to fans over the years from 2 to 7 blades metal to plastic whats yours called ??? Pete Pete I have a plastic fan but I confess I haven't counted the blades. "More than 2" is all I can tell you at the moment.. I seem to recall it was a bit of an improv/bodge getting it to fit so possibly isn't the right fan, and also it's possible that as part of said improv/bodge it was fitted the wrong way round (do the engine driven fans blow instead of suck if fitted the wrong way round?). Top of my list to check in the morning. Ben, Doug - when I had the block flushed they checked the water pump, thermostat and heater valves, all good apparently. Cheers Hugh Link to comment Share on other sites More sharing options...
AidanT Posted October 24, 2016 Report Share Posted October 24, 2016 Hi Is there a way to estimate how efficiently a water pump is working without a strip down? Aidan Link to comment Share on other sites More sharing options...
JohnD Posted October 24, 2016 Report Share Posted October 24, 2016 Cold start with rad cap off. Revving should cause a gush of coolant into the rad head tank. That's about it. I fitted a Davies-Craig water pump because of overheating under stress. Ground off the vanes in the mechanical pump, so that acts now as just an idler for the alternator drive belt. Result, excellent cooling under all conditions. John Link to comment Share on other sites More sharing options...
68vitesse Posted October 24, 2016 Report Share Posted October 24, 2016 A fan will still suck if fitted the wrong way round, air flow will decrease as the blades normally have an airfoil section. Regards Paul Link to comment Share on other sites More sharing options...
AidanT Posted October 24, 2016 Report Share Posted October 24, 2016 Thanks John I will check again. I had a flow but it was while the engine was at tick over it certainly wasn't a gush ! Aidan Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 24, 2016 Report Share Posted October 24, 2016 GT6 rad header is probably one of the worst for any visual down the filler but you should see the level drop a bit when you give it a short rev, Dont think you cant fit a triumph plastic fan back to front it would foul the radiator as there is little clearance when its right think last version was 7 bladed , but were there ...more Pete Link to comment Share on other sites More sharing options...
hughestill Posted October 25, 2016 Author Report Share Posted October 25, 2016 GT6 rad header is probably one of the worst for any visual down the filler but you should see the level drop a bit when you give it a short rev, Dont think you cant fit a triumph plastic fan back to front it would foul the radiator as there is little clearance when its right think last version was 7 bladed , but were there ...more Pete Pete you're right - once I looked at it, I remembered fitting it and it was a pig - very fiddly. If I'd tried to fit it the other way round it wouldn't have. I also checked and it is definitely sucking, not blowing, although the airflow is rubbish - mine is 8 bladed so maybe it's not a GT6 fan at all. Looks more like one stolen from a desk fan to be honest. All that aside, I've taken the car out for a couple of longer runs (20 miles or so still counts as a longer run for me at the moment) and it runs happily at 70-80C, and only gets hotter when it's stationary. Therefore, I shall: (i) Pick up a proper GT6 fan (ii) Fit an electric fan with override switch Then I'll be happy taking the car places where other people might be.. :-) Cheers, Hugh Si Link to comment Share on other sites More sharing options...
AidanT Posted October 25, 2016 Report Share Posted October 25, 2016 one more question for everyone! What is the "correct" running temperature for our cars? i dont man the temperature the gauge might read, more the actual temperature from a more accurate instument like a thermometer Hugh, if you were running between 70 and 80 degrees surely your thermostat would never be open? 82 degrees? i know my gauge is somewhat out the thermostat opens at around 180 Fahrenheit (sorry for mixing scales!) Aidan BTW I realise all cars are different - so a range? Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 25, 2016 Report Share Posted October 25, 2016 82 is its starting to open point, it opens more if it gets hotter and opens and closes all the time so it modulates to keep a steady tempersture between the cool incoming to the hot outgoing 312240 13 blade fan USA markets only now not available anyone going over the pond ?? Link to comment Share on other sites More sharing options...
AidanT Posted October 25, 2016 Report Share Posted October 25, 2016 Just checked and my gauge is about right 180 F is 82.2 C ! Motorway driving it sits at 190F or 87C. So I guess that's nothing to worry aboutAidan Sorry for the bit of drift Link to comment Share on other sites More sharing options...
hughestill Posted November 3, 2016 Author Report Share Posted November 3, 2016 Hi Aidan, I replaced my 82C thermostat with a 75C one so I'm guessing it's opening/closing as per Pete's post above, and doing a good job of modulating the temperature when there is cold air flowing freely. Pete - looks like my fan is actually from a Dolomite, don't know how much difference that would have made in terms of airflow but I'm guessing pretty marginal. I'm in the process of fitting a Revotec fan with an override switch, and there's no room to keep the orignal fan now. Cheers, Hugh Link to comment Share on other sites More sharing options...
Pete Lewis Posted November 3, 2016 Report Share Posted November 3, 2016 get it to switch in as early as possible you dont want high temp static air under the bonnet as that really upsets the mixture settings hence my love of engine fans Pete Link to comment Share on other sites More sharing options...
hughestill Posted November 7, 2016 Author Report Share Posted November 7, 2016 get it to switch in as early as possible you dont want high temp static air under the bonnet as that really upsets the mixture settings hence my love of engine fans Pete Pete, Yep, turned it to its lowest setting and am now feeling very smug and pleased with myself.... after a few minutes panic and irritation, when I realised I hadn't put a fuse in after I'd finished wiring it in (doh!), everything works perfectly. Got the temp up to the top of the gauge due to lack of fuse, but then after the fuse went in and fan went on, I couldn't believe how quickly it brought the temperature down - almost instantly to about 95C, then left it idling (translation: annoying the neighbours..) for about 30 mins and temperature stabilised at around 80-85C. Very pleased - thanks everyone for the advice along the way. Looking forward to getting stuck in traffic :-) !! Cheers, Hugh 1 Link to comment Share on other sites More sharing options...
Pete Lewis Posted November 7, 2016 Report Share Posted November 7, 2016 Glad you have a result, something that does get missed is its fine whacking more air through the rad but it has to get out somewhere much of it has to go down the tunnel all pretty tight for space maybe you need some giant bonnet louves ??? pete Link to comment Share on other sites More sharing options...
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