36 replies to this topic

[mcramsay]

After a bit of hard driving occasionally when the temp on the acewell is reading around 91 degrees( I think the acewell sender reads a little higher than the emerald water temp sender) the rad cap on the water rail decides to lift a little and eject a bit of coolant, I think the fan switch is set to come on at 94 degrees, so it's leaking before the fan kicks in, and I believe the zetec is meant to run a little hotter than normal? There is an out let on the water rail just below the cap( I think it is 8mm) and I currently have this blanked off. Do I lower the fan kick in temp or do I fit some kind of expansion tank? I'm guessing as the water gets near boiling temp it will rise enough to reach the 8mm outlet and then pass into the expansion tank, rather than come out the cap? I think the cap is an 18-22lb cap which came with the rail?

I just read the water rail information on the raceline website which says that the disadvantage of the water rail is you cannot tell how much coolant is in there and it will need regular topping up as it will " eject coolant" to find its own level.... That sounds like a load of crap, it would be a constant cycle of removing the cap, seeing no coolant, topping it up, loose it as you drive it, then top it up again etc etc etc...

[Simon B]

Raceline water rail.

I found that the finish on the top is a bit rough. You need a rubber gasket (or as I did - cut a bit of rubber out of the remains of the window seal) so that the seal between the cap and the rail body is airtight. This will allow coolant to expand into the expansion tank and when it cools will suck some back into the system.

Simon.

[mcramsay]

What is the plumbing required for the expansion tank? I see kit spares sell a nice alloy one!

[Simon B]

I used a cheaper option.

Just plumb the small top outlet to the expansion tank so that the pipe into the tank is below waterline. Mine has a small hole at the top to allow air out (and in).

The idea is that the coolant expands through the pipe into the tank and pushes fluid up (and air out). When the engine cools, suction pulls the fluid back (hence the tank pipe needs to be below water line) into the system.

The GBS one has an extra pipe which simply allows excess coolant out and down onto the road. (The system should never really do this unless REALLY overheating and boiling coolant)

Simon.

[merc190]

Can`t say i am a big fan of the water rail as many people have complained about it, i am using a header tank with no probs. Zetec is supposed to run at 20psi. I have also removed the small toggle in the bypass hole in the stat to allow for a more gradual warm up.

Marty Smith

[mcramsay]

I think the water rail is a much neater installation and does look good, I will def be fitting an expansion tank though. What temps are people's fans coming on for the zetec?

[Simon B]

A header tank and expansion tank are not the same.

A header tank is always under pressure and an expansion tank is not. The idea of the header tank is to be the highest point in the system. The raceline water rail does exactly that so a header is not really needed.

An expansion tank definitely IS required though for both systems as this allows excess coolant which has expanded due to heat to be caught and then sucked back into the system when the coolant cools down and contracts again.

I found that you need to get or make a rubber sealing ring between the filler cap and the top of the raceline water rail or this doesn't work as expected and just draws air into the system instead of the overflow coolant.

While on the move the gauge doesn't move above 70 - 75 degrees. I have the fan turn on around about 94 and off at approx 90.

Simon.

[florin metal works]

Simon, is your gauge correct? If so is not the engine running too cool for efficiency & power, thought the idea of the pressure cap was to allow the engine to operate at higher temp. without the water boiling off.

[Simon B]

That is something I will have to check. I will have to plug the laptop into the system and see what the ECU is reading and compare the two.

You may be right that the gauge is reading lower than the ECU is actually seeing. I'll try next time and update my results here.

Simon.

[mcramsay]

I also find the engine runs around 75 degrees when driving, although this is what is indicated by the acewell, I will check what water temp the ecu is seeing during normal driving, possibly a higher rated thermostat is needed

[kent zero]

Hi all,i had the same problem as you have,i replaced pressure cap and altered radiator cooling fan
temperature setting to operate at 94 and go off at 82 degrees.
You need to fit a expansion tank,i use same as GBS use with extra over flow out let,seems to be ok
now.

kent zero

[Simon B]

Hi,

I have now done a run of around 20 miles and logged the results the emerald was giving out and coolant temperature was between 72 and 81 degrees so I think that the gauge reading is about the same value as well.

So at those temperatures, the fan never started up during the whole trip.

Simon.

[mcramsay]

I would expect I'm getting the same results... That seems too cold, I would expect too see the water stating at 90 even when driving... Maybe the thermostats that  come with the water rail are opening too soon, possibly the larger rad on the zero is causing over cooling?

[Longboarder]

I tend to run the ST and the previous zetecs at 95 to 100 and thats what the fan does. More power/efficiency and less engine wear. Easy to get overcooling with zetecs depending on your plumbing and stat. I bought a water rail in 2006 looked at it, read the instros,offered it up, sold it on at a loss. Didn't like the way raceline wanted it to work.

Nigel

[Simon B]

Hi,

I have bee reading various web sites and they have strange temperatures - fahren-wotsits and say a 180 degree (or 82 degrees Celsius) is the right temp to be using. So I think the engine isn't REALLY too cold (well - slightly)

It's a bit of a trade off between power, fuel economy (what's that ? ) and wear on engine parts. I think that the oil temperature will be higher than coolant, if only because it gets closer to the source of heat and so will help to boil off any collected water from the combustion process which gets past the piston rings.

That's one reason why cars NEED a good long run in order to maintain their reliability and to reduce wear and tear. Any collected water vapour will dissolve nitrogen gas by products and you get nitric acid building up in the engine - not good. So - happiness is a warm engine

Too hot is worse though as it could start melting bearing surfaces and such promoting rapid wear.

And at the moment, the colour of the oil is still fairly golden and transparent after around 680 miles from new so do you think it's been "run in" yet ?

Of course, I could be talking up the wrong tree?

Simon.