WLJayne

WLJayne

Well-Known Member
Hello folkies,

The cold weather has brought an interesting problem to light with my EWP system - in cold temperatures and high speeds the pump starts to overcool the engine. The other day it was about 0 degrees on the M1 and overcooling started at about 55mph.

Davies Craig say put a thermostat with two 5mm drilled holes in it into the system. How about no, it's working really nicely now otherwise.

So I was thinking of making a blanking board for the lower grill, mine is facelifted so has three grills. I think that blanking this grill off would make a big difference as the bottom of the rad is where the coolant is getting that last big hit of cooling before it exits.

The lower grill is mild steel, so I was thinking I could make a magnetic blank that I could remove in summer - though to be honest the overkill radiator is pointless now that the cooling system is smart and adaptive so I may leave it on all year round.

Does anyone know of a weatherproof magnetic material I could cut to shape? Or magnetic strips that aren't going to fall off whatever I put them on? It's a dead simple project, it'd just be cool to hear your ideas about it :). If this doesn't work then I'll try a flow restrictor, but I know it's a ram air problem rather than anything else and limiting the amount going through the rad should to the trick nicely. Might bump the overcooling up to say 80mph in 0 degrees - as if I'm ever gonna do that!

Oh by the way, 600 miles since we fixed the system and not a peep other than this overcooling niggle - when I get to 3000 then I can start thinking about cool mods again ;).

Will.
 
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Is'nt the ewp thermostat controlled? Have you taken the normal stat out? If so did you fit the restrictor plate? It's easy to make one by removing the valve and capsule from an old stat ;)
 
Nodge68 said:
Is'nt the ewp thermostat controlled? Have you taken the normal stat out? If so did you fit the restrictor plate? It's easy to make one by removing the valve and capsule from an old stat ;)
Click to expand...

The EWP has it's own temperature sensor. It;s worked fine until these freezing temperatures. The car is 2004 so had the PRT which has been removed. I'm reluctant to fit a restrictor as most other electric pumps don't do well with alot of back pressure.
 
WLJayne said:
The EWP has it's own temperature sensor. It;s worked fine until these freezing temperatures. The car is 2004 so had the PRT which has been removed. I'm reluctant to fit a restrictor as most other electric pumps don't do well with alot of back pressure.
Click to expand...

If it was fitted with a prt then it will or should have the factory restrictor anyway. I assume the engine is coolant is thermosyphoning through the rad without your ewp running?
 
Nodge68 said:
If it was fitted with a prt then it will or should have the factory restrictor anyway. I assume the engine is coolant is thermosyphoning through the rad without your ewp running?
Click to expand...

The EWP is always running on at least 6v but because it can't go any lower than 6v it pumps too much cold water thourgh the block. A radiator blank should mean less cold water so the pump stays above 6v eben in cold weather ;).
 
WLJayne said:
The EWP is always running on at least 6v but because it can't go any lower than 6v it pumps too much cold water thourgh the block. A radiator blank should mean less cold water so the pump stays above 6v eben in cold weather ;).
Click to expand...

Ah I see the problem. Blanking the rad is a sound idea ;)
 
Nodge68 said:
Ah I see the problem. Blanking the rad is a sound idea ;)
Click to expand...

Glad you agree :). The plus side of this is that at high speeds the pump is hardly consuming any energy so power and fuel economy will be getting a considerable gain. I wish i had some way to measure it!

Well tonight I've got to pick up my girlfriend in Coventry so I'll brim the tank and then brim it again when I get back to see how much fuel I've used. It's 80% motorways on that journey.

Will.
 
Your mpg will increase a bit as the engine driven pump will use a couple of Ftlb of torque which requires fuel to produce that torque. However the the electric pump will use power generated by the alternator which will use more torque to supply that electric to drive your ewp ;) I reckon you will see a slight gain in mpg ;)
 
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Freelaner said:
if the EWP is working correctly there shouldn't be a problem, shirley
Click to expand...

There is a problem, and don't call me Shirley :D.

It's not the EWP's fault - it's that there is so much cold water coming out of the hoooooooooj radiator that the EWP doesn't know what to do with it all and can't hold enough back to maintain 85-90 degrees. It's kindof a mindfook as it's all arse about face. But if there's just a little less cold water coming out of the rad then the pump will be able to regulate it within it's voltage range. The issue is that the system relies of pump RPM to regulate temperatur rather than thermostat aperture, and an excess of cold water is a problem for the former and an excess of hot water is a problem for the latter. However if I ever do decide to cross the Gobi, all I have to do is remove the blank and suddlenly I've got access to freakin tons of cold water at any rev range :).

The only slight disadvantage that I'm anticipating is when I want a hot blower of max fan speed - usually the thermo would close off a bit and use the heater as the radiator whereas the EWP will always send it through the main loop. However I don't ever have it on full blast as it gets uncomfortably hot even at the lowest fan speed now. In fact all I have to do is leave the vent open and heat just radiates out of them even without the blower going. So that's that sorted!!
 
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How about an over-ride circuit on the ewp that slows it down when it is overcooling?

or would this add to an already mind boggling situation.:confused:
 
Freelaner said:
How about an over-ride circuit on the ewp that slows it down?

or would this add to an already mind boggling situation.:confused:
Click to expand...

The EWP is already running at minimum voltage in this sitauation - and even then it's supplying too much cold water to the block. If the sensor detetcs it going really cold then it starts pulsing the pump like it does during warmup but that's not ideal. All that's happening is that the flow rate to temperature drop ratio is too great inside the rad - if we can't drop the flow rate any more then we have to decrease the temp drop by blanking off a section of the rad :).
 
WLJayne said:
The EWP is already running at minimum voltage in this sitauation - and even then it's supplying too much cold water to the block. If the sensor detetcs it going really cold then it starts pulsing the pump like it does during warmup but that's not ideal. All that's happening is that the flow rate to temperature drop is too great inside the rad - if we can't drop the flow rate any more then we have to drop the temp drop by blanking off a section of the rad :).
Click to expand...
Land Rover Radiator Muffs - Defender, Discovery, Series, Radiator Muffs ;)

might look :cool: anorl ;)
 
Yep that's the sort of thing but I don't want to cover up the whole grill - just the lowest grill opening ;). Some of this magnetic sheet cut to perfect size should to the trick.
 
They do like nice though. I expect a rad muff really helps in winter with the Fender's heater!!
 
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