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Hi,

I've had my TR5 for 45 years so you'd have thought that there wouldn't have been a problem that I hadn't encountered before, wrong....

Car is cooled via Evans coolant & Kenlowe fan. At a stand still in the garage it ticks over nicely with the temperature hovering around the normal (mid-way) point on the gauge. The fan kicks in fine and maintains the temperature. However, take the car on the open road and almost immediately the temperature soars 'till it's "bending the needle". Today I swapped the thermostat and ran the engine up to temperature with the radiator cap off to purge any air-locks. All fine and dandy 'till you drive it and then scorchio! Opening the heater valve to allow more coolant into the system makes no difference. Now, in recent weeks the only other change to the cooling system was the installation of a new Moss (pattern part) water pump, could this be the culprit? My thinking is that the cooling system with Evans and Kenlowe is VERY efficient but that it is dealing with coolant in the rad and environs only, perhaps the pump is not working and therefore not circulating the coolant throughout the entire system? Hence, when the car is on the road and working harder the system is unable to cope, (as am I !!!!).

No answers on a postcard please, I need help now before the car or me has a breakdown!

Steve Walter

PS I am not overly technical.

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So what was it doing before the water pump change, and why did it need a water pump ?

Jerry

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Before replacing the water pump cooling was fine but there was a slight leak from the pump so I felt it prudent to change it as we live in France most of the year and cover umpteen kilometers on french autoroutes.

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When you opened the heater valve, did the heater get hot ?

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Would seem to point to something not right with the new pump, but can't think what - not much to them really. Have you still got the old one to put back on?

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Pump impeller spinning on the shaft at driving revs, OK at tick over revs?

Wasn,t there a batch of pumps with simply interference fit impellers, I.e. Not fixed with a Pinza?

John.

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Ok, to foster461 not sure but I don't think so. To jerry tr5 I agree but no, I haven't got the old one. To John Morrison I see what you mean but I've no idea if interference or fixed with a "Pinza" (is this a type of cotter pin?).

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Hi Steve,

 is the rad fan spinning in the correct direction,

Standing still it doesn;t matter which way it spins but when moving you may be trying to push rad fan air into the incoming air stream

Have worked on the fan recently?

 

Roger

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Since the problem has started since fitting the new pump I would think it is most likely the pump at fault.

I know the Evans coolant is more viscous than regular anti freeze mix so if the impeller is not a tight fit on the shaft it could spin. Looks like its time to take it apart again

Neil

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Does the fuel gauge go up at the same time the temp goes up?

if so suspect the voltage regulator, otherwise the pump or perhaps the temp sensor.

steve

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1/ I wish! 2/ both Kenlowe thermostat (sensor) & temp gauge register that it's hot, therefore coincidence aside I think it's hot. So, still pump methinks. Thanks though.

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Everything coincides with the pump-change.... I’d go straight back there.

....... Andy 

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Have you properly vented all air out? An air bubble can do this and our cars are famous for that. 
There are several posts on this forum, I suggest you read a couple so you better understand the issue.
 

Good luck,

Waldi

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I had  problems with my water pumps for many years. In the end I sent my original away to a forum member in the Netherlands. He rebuilt it with a stainless steel shaft and special seal. While it was away I fitted a " County " pump which I bought from Revington because I was near them. I has planned it as a stop gap only, until my special was delivered. But it did not leak and has been on the car since March 2016. I have the special pump in the boot for fitting if I have a problem away from home. It is best to buy a new belt pulley from the same supplier as the pulleys vary in size and quality. It is also important to calculate the clearance of the impeller to the housing, to make it as close as possible.

I am assuming that the water pumps on your TR5 are basically the same as the TR3. Probably the same problems anyway.

Richard &B

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So, I think the clearance from impeller to housing is important. Having spoken to Revington TR (Dan) says ideally the gap should be no more than 2mm, (1 for preference). He has seen gaps as much as 5mm and these simply don't work, merely frothing the water/coolant. However I am now thinking that the rad might be blocked / sludged up, despite umpteen flushes. The car was off the road for several years with all fluids present, the process of re-commissioning the vehicle started in 2016 and it's been an uphill struggle. I cannot remember the last time the rad was touched but certainly not since 1992 and so my next step will be to get it re-cored, even without the current problem I think this would be prudent. 

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Funnily enough i was going to suggest that the rad perhaps needs re cored . That would give you time to check out the pump whilst the work is being done with more room to work , Bonus. Evans is very expensive and the fewer times to remove it and replace it the better.

When the Evans was installed did you get the water jacket cleaned thoroughly? solidified sediment is difficult to shift.

Rod.

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But you indicated that the cooling was fine before changing the pump?

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When I rebuilt my TR3a I fitted a new high capacity pump and it didn't seem to work properly.  When I removed it and belatedly checked the impeller clearance it was huge.  No wonder it didn't work properly. I rebuilt the old one with a stainless steel shaft that a friend ran up for me and was extra careful about setting the impeller clearance and have since had no problems.

Rgds Ian

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24 minutes ago, Ian Vincent said:

When I rebuilt my TR3a I fitted a new high capacity pump and it didn't seem to work properly.  When I removed it and belatedly checked the impeller clearance it was huge.  No wonder it didn't work properly. I rebuilt the old one with a stainless steel shaft that a friend ran up for me and was extra careful about setting the impeller clearance and have since had no problems.

Rgds Ian

I had same issue with two 5 vane 'Lucas' hi capacity water pumps for TR2-4A.

Here is my solution fitting a shim in the pump housing to close down the impeller clearance.

Cheers

Peter W

 

Pump Clearance.jpg

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To Waldi, Yes, before changing the pump I drove 750 miles in two days with no problems, all this with a slightly leaking OE pump and water/antifreeze coolant mix. Hence the reason for changing the pump. During routine maintenance the system was flushed, new pump installed & cooling system filled with Evans. This is where I am today.

However, go back a couple of years & immediately following the re-commissioning in 2017/18 the system was thoroughly flushed and filled with Evans. Shortly after this the car left me at the side of the M25  three times on one journey massively overheating. Having no Evans available it was flushed again and filled with the aforementioned water/antifreeze mix and was fine...

So does my car not like Evans coolant? I'm not sure. My feeling is that although the system has been "flushed to death" the car sat for several years with coolant in situ, so with the combination of a rad that's been in the car for twenty five, thirty odd years and the long term lay-up my feeling is there's a lot of sludge "washing off" and sloshing around. As I muted re-coring is probably prudent anyway.

Why do I use Evans? We live in the SW of France most of the year and temperatures of 35 - 40c are not unusual in the summer months. As an aside I also own X747 the Wasp prototype TR5 and he seems to like Evans. Go figure.

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You seem to have highlighted your 2 problems. Either Evans or pump.

Change from Evans back to water, no cost.  if not try a different pump. All cheaper than a rad.

To others    how do you check the clearance ?

Roy

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I have said this many times DO NOT USE IT  the system will not pressurize correctly get rid of it.

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8 minutes ago, steve walter said:

Why do I use Evans? We live in the SW of France most of the year and temperatures of 35 - 40c are not unusual in the summer months.

Which is exactly the wrong reason for using the stuff.   It is worse at cooling than water because the specific heat of water is higher than that of glycol (or any other liquid come to that). Put simply, water can shift 30% more heat per unit volume. The temperature of your coolant may look good (which is what the gauge measures and the thermostat regulates) but the temperature of the engine block will be higher than if you used water. 

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