Overheating Posted June 12 Report Share Posted June 12 Hi I’ve just finished complete restoration of my 1957 tr3, I’m having odd problems with over heating, when ticking over in garage the temp sits just over half way mark 75c. That all seems fine until I take car for a spin then temp shoots up to 100c in less than half a mile. The car has a a new radiator, new water pump, new stat,new belt, I’ve also flushed the system . Has anyone got a clue as to what is causing this. Also when I park car and leave engine running temp will drop . Quote Link to post Share on other sites
stuart Posted June 12 Report Share Posted June 12 Check your timing and mixture. Stuart. Quote Link to post Share on other sites
iain Posted June 12 Report Share Posted June 12 5 hours ago, stuart said: Check your timing and mixture. Stuart. Running ignition too advanced and running carbs too lean will potentially cause this issue. Check these out first before you start to suspect things like piston ring tolerances etc. Quote Link to post Share on other sites
Overheating Posted June 12 Author Report Share Posted June 12 Yes I've checked timing and retarded a couple of clicks also if anything it's running a little rich. I've noticed that the bottom of radiator does not get hot for quite a while which makes me wonder if the new pump is faulty! Quote Link to post Share on other sites
Ian Vincent Posted June 12 Report Share Posted June 12 If it’s a “high performance” water pump it’s possible the impeller isn’t sitting far enough into the housing with the result that the pump is pretty inefficient. I had that problem. I rebuilt my original water pump paying close attention to the dimensions given in the WSM and problem solved. Rgds Ian Quote Link to post Share on other sites
RogerH Posted June 12 Report Share Posted June 12 Hi Ian I think Pete Wigglesworth solved this problem quite some time ago. The impeller doesn't sit far enough into the body - so a packer is needed. Roger Quote Link to post Share on other sites
woodward Posted June 12 Report Share Posted June 12 I had similar symptoms on my TR4. In my instance the cause was an air lock in the cooling system. This was solved by removing the lower hose from the water pump, filling the hose with water and then quickly reattaching to the pump. There may be other methods but this worked for me. Myles Quote Link to post Share on other sites
Overheating Posted June 12 Author Report Share Posted June 12 Thanks all for your replies, I'll take pump off and check that out. Thanks again. Alan Quote Link to post Share on other sites
rcreweread Posted June 12 Report Share Posted June 12 Alan - if you have your original water pump, send it off to these people who will recondition it, with a lifetime guarantee : EP Services https://www.ep-services.co.uk/ Unit 1 Central Trading Estate, Cable Street Wolverhampton, Staffordshire, WV2 2RJ England Phone: 01902 452914 Out of hours: 07770 747724 Also, I suggest you ask the Mods to change the title of your post to be relevant to your query such as "TR3 Overheating issue after rebuild", as this will allow the issue to be more easily searched for Cheers Rich Crewe-Read Quote Link to post Share on other sites
BlueTR3A-5EKT Posted June 12 Report Share Posted June 12 (edited) 47 minutes ago, Overheating said: Thanks all for your replies, I'll take pump off and check that out. Thanks again. Alan Post a photo of the pump and impeller. it wants to have a square cornered impeller to match the base of the pump housing NOT sloping like a TR 7 pump impeller Measure the protrusion of the impeller and the depth of the housing.also measure the thickness of the gasket Do some sums Impeller to pump housing clearance. You want 0.010” minimum when all bolted up. Turn by hand to confirm before running. Probably 0.040” max. I added a shim 0.080” thick in the base of the housing on my car to get the Lucas green box high performance water pump impeller to be in the correct depth. Piece of junk! The other way is gulp and buy a Racetorations water pump. Fit and forget I am told. I have fitted two so far and had no complaints. Edited June 12 by BlueTR3A-5EKT Quote Link to post Share on other sites
BlueTR3A-5EKT Posted June 12 Report Share Posted June 12 (edited) 8 hours ago, Overheating said: Hi I’ve just finished complete restoration of my 1957 tr3, I’m having odd problems with over heating, when ticking over in garage the temp sits just over half way mark 75c. That all seems fine until I take car for a spin then temp shoots up to 100c in less than half a mile. The car has a a new radiator, new water pump, new stat,new belt, I’ve also flushed the system . Has anyone got a clue as to what is causing this. Also when I park car and leave engine running temp will drop . Which thermostat type have you fitted? Take it out and dunk it in boiling water to be sure it actually opens at the specified temperature. I’ve had the job of testing new thermostats for another type of car and believe me they do not all work as expected or specified. Does the cooling system loose water? Is the sump oil level rising? Just to be sure that there is no internal or gasket leak. Edited June 12 by BlueTR3A-5EKT Quote Link to post Share on other sites
Ralph Whitaker Posted June 13 Report Share Posted June 13 (edited) To expand on Peters post above, if you have the original type of shrouded thermostat then fine, if you have the more modern type then the water pump housing should have a restriction in the by-pass. Later housings had a reduced hole, but TR2/3/3a housings had the large hole. If the car is a 3a have you fitted the radiator cardboard ducting. Ralph Sorry, I have just edited the above as the restriction is in the water pump housing, not the pump itself as it read before. I made a brass plug with a 3/16 hole to reduce the by pass hole in mine which has worked well. Edited June 15 by Ralph Whitaker Quote Link to post Share on other sites
Ian Vincent Posted June 13 Report Share Posted June 13 12 hours ago, BlueTR3A-5EKT said: Impeller to pump housing clearance. You want 0.010” minimum when all bolted up. Turn by hand to confirm before running. Probably 0.040” max. I added a shim 0.080” thick in the base of the housing on my car to get the Lucas green box high performance water pump impeller to be in the correct depth. Piece of junk! I have an old WSM which gives instructions for refurbishing the water pump and it says that the impeller should be pressed on until there is 0.085” clearance between the rear face of the impeller and the pump body, so that is what I did. I then did the maths to check the clearance between the impeller to rear of housing clearance and from memory it was 0.017”. Rgds Ian PS I had a friend with a lathe run me up a new shaft in stainless steel to a set of dimensions provided by Don from Canada. If anyone is interested, I still have his sketch somewhere and can post it here when I find it. Quote Link to post Share on other sites
Overheating Posted June 14 Author Report Share Posted June 14 Ok I've taken pump off which is a moss pump with the square four vane impeller, I've put in a shim as suggested (50 thou) also check head gasket, oil is very clean , it just appears that the pump is not circulating, would it make a difference if I remove thermostat completely? As it is still taking a very long time for bottom of radiator get hot. Regards Alan Quote Link to post Share on other sites
RobH Posted June 14 Report Share Posted June 14 The thermostat is really the only other simple thing than can stop circulation. If you run without it the engine should over-cool of course and not get up to proper temperature. Quote Link to post Share on other sites
Ian Vincent Posted June 14 Report Share Posted June 14 If you have put a shim between the pump body and the block you are increasing the clearance between the impeller and the rear of the housing. I have always thought that the objective is to reduce that clearance to a minimum as that increases the effectiveness of the impeller. Rgds Ian Quote Link to post Share on other sites
Overheating Posted June 14 Author Report Share Posted June 14 Also this my be a silly question, when you remove pump from pump housing the first chamber which still holds a little water appears to be blanked off, ( no out or in let) is that correct? Regards Alan Quote Link to post Share on other sites
Overheating Posted June 14 Author Report Share Posted June 14 No I've put shim behind impeller. Quote Link to post Share on other sites
BlueTR3A-5EKT Posted June 14 Report Share Posted June 14 1 hour ago, Overheating said: Ok I've taken pump off which is a moss pump with the square four vane impeller, I've put in a shim as suggested (50 thou) also check head gasket, oil is very clean , it just appears that the pump is not circulating, would it make a difference if I remove thermostat completely? As it is still taking a very long time for bottom of radiator get hot. Regards Alan How have you attached the shim in the pump housing? I used loctite and 3 countersunk M3 screws Quote Link to post Share on other sites
BlueTR3A-5EKT Posted June 14 Report Share Posted June 14 10 minutes ago, Overheating said: No I've put shim behind impeller. Wrong place. I should have been clearer in my explanation Quote Link to post Share on other sites
RobH Posted June 14 Report Share Posted June 14 (edited) Personally I would have looked at the thermostat first. Not only is it simpler to get at, a stuck 'stat is more likely to give the symptoms described. Silly question perhaps - but did you fit it the right way round with the capsule towards the cylinder head? Edited June 14 by RobH Quote Link to post Share on other sites
Ian Vincent Posted June 14 Report Share Posted June 14 1 hour ago, Overheating said: No I've put shim behind impeller. I don’t understand how you can fit a shim behind the impeller without removing it from the shaft and in order to do that you need a puller. As I said in my earlier post the important dimension is between the vanes of the impeller and the rear of the pump housing on the block. In other words put a depth gauge on the machined face of the housing and measure the depth, (d). Then measure from the front face of the pump body to the tips of the impeller, (p). Subtract p from d and the answer should be between 10 and 20 thou. Rgds Ian Quote Link to post Share on other sites
Ralph Whitaker Posted June 15 Report Share Posted June 15 On 6/13/2024 at 6:38 AM, Ralph Whitaker said: To expand on Peters post above, if you have the original type of shrouded thermostat then fine, if you have the more modern type then the water pump housing should have a restriction in the by-pass. Later housings had a reduced hole, but TR2/3/3a housings had the large hole. If the car is a 3a have you fitted the radiator cardboard ducting. Ralph Sorry, I have just edited the above as the restriction is in the water pump housing, not the pump itself as it read before. I made a brass plug with a 3/16 hole to reduce the by pass hole in mine which has worked well. Just bumped up my previous post as I realised I may have confused the issue originally and have edited it accordingly. Ralph Quote Link to post Share on other sites
roy53 Posted June 15 Report Share Posted June 15 Try another pump. If not the problem it's always good to cary as a spare. Seems a cheap option after all the work you are doing. Hopefully an air lock but unusual in a 4 cyl. I would have surgested a blocked rad but as new probably not. Roy Quote Link to post Share on other sites
Overheating Posted June 15 Author Report Share Posted June 15 Thank you RobH yes I'm a twit I should have checked stat first, it was a brand new one so I presumed it would be ok, I've completely removed it a all is now fine. Obviously I'll need to replace it, what's the best one I can replace it with? Thanks again to all who have come to my rescue. Regards Alan Quote Link to post Share on other sites
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