Pressure in water system

[zulublue]

My RRC has been blowing a cloud of white smoke out on start up this lasts for about 5 minutes depending on temperature, not sure if this is just condensation from the exhaust, I have had a CO2 test done yesterday and all seems well, the other day when I got home there was water coming from the overflow on the boost bottle, I think I may have the thermostat set to high on the kenlowes, so have now lowered it a touch, but one thing I do know is that the upper pipe from the rad seems under a lot of pressure once it has been running for 10 minutes or so, I released the top of the boost bottle and received a rush of air from it and pipe was relieved. Now the boost bottle is from a 82 carb engine and I now have a 1990 efi engine, would there be a difference in the pressure on the spring for these years and if so would having a over pressured spring cause any problems?

[Range Rover Blues]

The 3.9 has a bigger header tank yes, probably for a reason.

The tool you need aparently is a leak-down tester.  I've found one on Flea-Bay for less than £50 (snap-on is over £200 :shock: ) plus you need a compressor.  Unlike a compression test this will check the rings, head gasket/cracked block and valves.  If you hear air escaping then you can tell where from, if the coolant bubbles up then head gasket/block, if the crankcase breathes then rings, if the inlet whistles then valves if the exhaust whistles then valves.  Going to get one soon myself.

[zulublue]

Cheers RRB

So checking for CO2 in the water is of no use?
Do you think the top on the boost bottle is too strong?

P.s. its a 3.5

[Range Rover Blues]

I think they all ran about the same pressure and IIRC they all use the same thermostat which would confirm that.  Don't worry if the pipes go hard under pressure, that's usually a good sign.

All cooling system breath out once they are hot, I'm tempted to say it was just a case of you havn't seen it before, plus the Kenlowes coming in too late.

If it's working fine now then leave it.

As for the CO2 I'm not convinced about it and it's an expensive test to repeat.  Rather like a compression test it doen't give you the whole story and my concern for your engine is the white steam.

Is it using water?

[Range Rover Blues]

P.S. any raise in pressure would also raise the boiling point, that's why the coolant is pressurised.

[Yoshi]

See now mine is the opposite, its not using any water now, and that top pipe is limp as anything, took the old girl out for a fierce run yesterday, did some stuff that would really make the temp rise, and nothing happened, stayed at the same temp the whole time (like it used to before the old rad blew) yet this top pipe stayed limp and you could easily squeeze it, but when i did squeeze it you could hear the water bubbling from the air i pushed through in the reservoir.

[zulublue]

I think the temp issue is down to following instructions, as when the viscous fan was on, the guage went to around 1/3 of max, now on the kenlowe instructions it say take it to about 2/3 then kick the fans in to set the guage, so I now must assume the guage is out!

[Range Rover Blues]

I set mine so that they don't come on when I'm driving along with air going through the rad, as soon as I stop and the temp goes up a little they come on.  Otherwise they will be on when you are driving and you might as well keep the viscous fan.

[zulublue]

Yes, sounds like I have them set too high then.

[Range Rover Blues]

If they come on with the needle still on the guage then maybe not, the electric fan switch on the A/C cars is set quite high :?

[zulublue]

I think I will do what you have done and over time alter the setting to come on just after the point of stopping on a run. up to now this has been 100% out I will see if this affects the pressure in the pipe.

[Range Rover Blues]

Pressure in the pipe is unltimately set by the cap on the header tank, about 12PSI IIRC will raise the boiling point to over 110Deg.