Thinking of throwing in the towel

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Here's the reply I got from DC,

Hi Richard,

I installed the EWP and controller in my Land Rover Freelander and I really can't fault it, I'm very pleased. However this is a pretty serious issue that I need help with. When the pump is operating it forces a huge amount of coolant into the header tank, and the coolant is forced out of the cap in worrying quantities. I had to top up the system this morning and then had a nasty airlock overheat on the motorway, not a pleasant experience! In case you need to know, I mounted everything as per instructions and the unit operates perfectly, I mounted the pump on the lower radiator hose so that it pumps the cooled liquid into the coolant rail behind the engine as per the original mechanical pump's configuration.

Is there some way you can think of to stop so much coolant being forced out of the header tank? Sounds like the cap is not holding pressure - should be about 21 psi? Can you have it tested at a garage or just invest in a replacement - maybe go to 25 psi. I cannot image that the EWP is generating enough pressure to blow past a cap operating to specification.



This didn't occur with the mechanical pump and I wonder whether the EWP80 might just be a bit too powerful for the cooling system in this car. Don’t think so.



To help you, I have attached a diagram of the Freelander's cooling system showing where the EWP is mounted. Got it - if the EWP pumps into the header tank, when the EWP slows down the coolant should be sucked back into the main system.

I'd be grateful for any help you could give me,



Please keep me informed of progress and let me know how you get on.
 
"I cannot image that the EWP is generating enough pressure to blow past a cap operating to specification. - if the EWP pumps into the header tank, when the EWP slows down the coolant should be sucked back into the main system."

Sort of what we thought... The EWP shouldnt be creating that much pressure. If you can try getting the pressure checked in the coolant tank with the EWP running, without the engine running and then with, cold and hot. That should give you some definative figures to work with.
 
"I cannot image that the EWP is generating enough pressure to blow past a cap operating to specification. - if the EWP pumps into the header tank, when the EWP slows down the coolant should be sucked back into the main system."

Sort of what we thought... The EWP shouldnt be creating that much pressure. If you can try getting the pressure checked in the coolant tank with the EWP running, without the engine running and then with, cold and hot. That should give you some definative figures to work with.

That's what I think! I suspect it's a plumbing issue more than the ewp itself.
Basically it shoves it all into the header tank then when it runs it may be creating an airlock or localised hot spot that slowly pushes it out. I think stop it shoving it into the tank and it'll stop loosing it! ;)
 
I just spoke to the bloke at MAW Solutions where I bought it, very helpful chap. He also reckoned that re-routing the feed hose to before the pump intake would solve the problem as coolant shouldn't be forced into the tank. He said that all domestic central heating systems use this configuration.

We got some thinking to do then DD :rolleyes:.

Will.
 
Thats it Will, don't give in yet..........

I'm sure DaVinci made lots of errors before finding the right solutions to his inventions, Dyson before creating the "perfect" vacuum cleaner (or most expensive mainstream one, you choose!!), and Edison to boot, so keep fighting the fight..............





Or give in and buy a d.i.e.s.e.l................. just a thought :cool:
 
Thats it Will, don't give in yet..........

I'm sure DaVinci made lots of errors before finding the right solutions to his inventions, Dyson before creating the "perfect" vacuum cleaner (or most expensive mainstream one, you choose!!), and Edison to boot, so keep fighting the fight..............





Or give in and buy a d.i.e.s.e.l................. just a thought :cool:

I would have much preferred a Doozle and no mistake, it's only because this car was offered to me for chicken feed that I took it as I was looking for a new car after I wrote off my previous one. To be honest if I'd been shopping for a new used car I wouldn't have been able to afford anything like a decent Freelander. The fact that I have been able to do it up a bit at a time when I can afford it is the only reason I've got this far with it. Certainly not in a position to get a diesel at the moment.

We reckon we know exactly what the trouble is now - basically the header tank feed hose (in any cooling system) should be upstream of the pump - i.e. the pump should be pulling past the tank - not pushing into it.

I'm going to find a reducing T connector and mount in in the lower rad hose before the pump and re-route the feed hose there. The reason that this problem is happening is that with the standard system the mechanical water pump is downstream of the feed line, so it sucks coolant down the pipe instead of pushing it up there.

That's the theory anyway. If anyone knows where I can get a 32mm x 15mm x 32mm T connector in a suitable material I'm all ears as I'm not having much luck online. I have a 32 x 32 x 32 from the old thermostat bybass but then I'd need a 32 to 15mm adapter to fit the smaller hose to it. Once I have the necessary gear it won't be a very difficult job.

Will.
 
Being a heating engineer myself, I can safely say that a domestic central heating system has (obviously) a load more pipework in which to 'lose' the pump pressure, if not the velocity of the water.

It sounds as if your pump velocity may be too much for the relatively short route that the water has to flow. If you consider that there may be 100m of pipework or more in a domestic setup, then what your system is doing may be a tad overkill. What sort of flow speed do you get with your setup?
 
Being a heating engineer myself, I can safely say that a domestic central heating system has (obviously) a load more pipework in which to 'lose' the pump pressure, if not the velocity of the water.

It sounds as if your pump velocity may be too much for the relatively short route that the water has to flow. If you consider that there may be 100m of pipework or more in a domestic setup, then what your system is doing may be a tad overkill. What sort of flow speed do you get with your setup?

i doubt that, as it is an automotive pump.
 
What sort of flow speed do you get with your setup?

The controller varies the flow rate in order to remain within a 3 degree variance of the target temperature (in my case 90 degrees.) It can go up to 80 Ltrs/min but I don't think it ever gets that high under normal driving conditions. I have no idea what the average flow rate is but it would have to be similar to the mech pump or it would cool the engine too much.
 
Ok, so with all of these HGF issues, what would the problem be if you were to revert to running the engine without a stat in the summer, and put it back in the winter, like the good old days when a motor was getting too hot? ;)
 
This is not a HGF issue, the pump (when it's teething problems have been worked out) should significantly reduce the chance of repeat HGF. The thermostat has been deleted as it has been replaced with what essentially amounts to a digital thermostat in the form of the controller. The controller senses coolant temp through its own dedicated sensor mounted on the head outlet, and then varies the flow rate in the cooling system to achieve the desired temperature range. When you have both the controller and the old thermostat, the work against each other which is the cuase of every issue I have seen on the net with these systems - people just don't follow the instrictions! DC are very explicit in their instructions that any thermostat must be removed if the controller is to be used. This is not a problem with the head, or the new pump system - it's purely a problem caused by the flow initiator being moved to another point on the system. When the penny dropped it made total sense and hopefully DD's logic about moving the feed hose will solve the problem entirely :).
 
You say that, but the flow rate from an EWP is minimum 15 ltr/min, 115 ltr/min maximum, a Grundfos pump max around 38 ltr/min. Whether it is automotive or not, a pump is a pump, and its velocity is relative.

Sorry but that's not right. The EWP80 pumps a max of 80 L/min, I don't know where you got the min flow rate spec from, can you link to the info?

Just because it can go up to 80 doesn't mean that it does, the controller varies the flow rate depending on the engines cooling needs which are not massive in a 1.8. Sure if it was fitted to a track car with a V6 engine the controller might decide to give full power to the pump when the car is doing 7k rpm plus but it isn't doing 80 L/min on my way to Sainsbury's. The minimum flow rate, whatever that is, is not really an indication of minimum flow rate because the pump pulses on and off for different periods. So for example, during the warm up cycle the pump goes on at 15 L/min (assuming that figure is correct) for 10 secs and then off for 30 sec, so it is really only moving 5 L/min. When it reaches target temp it goes to constant operation with varying flow rates - for most driving conditions you probably only need 20 or 30 L/min so that's what the pump provides.

It's a very clever system and the operation of the system isn't what's causing this problem.
 
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