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Cold Header Tank
edspurrier - 27/2/09 at 07:02 PM

Confused. FLushed my coolant last weekend and refilled it, ran it until warm, squeezed bubbles out, topped up and cap on.

2.0 XZetec, plumbed according to the Toyne advice.

Ran it idle today until warm, cap on, to check. Warmed up slowly, seemed OK, fan cut in so stopped and checked the hoses. HEader tank and bottom hose both feeling cool to touch.

ANy ideas? Would have thought there was plenty of circulation through the header. Released the cap slightly and there is plenty of pressure in it.

Thanks
Ed

Paul TigerB6 - 27/2/09 at 07:12 PM

Mine was the same on my old Zetec Tiger - simply plumbed in as an expansion bottle so didnt get warm. Feel down the hose towards the radiator and you should feel the hose gradually getting warmer (and probably burn your arm on the exhaust!! )

edspurrier - 27/2/09 at 07:14 PM

Ah, thanks. Makes sense. It did warm up previosuly, but there was a vast amount of gunk in the system which found its way to the tank, plus no shortage of airlocks, so that won't have helped.

Ta
Ed

britishtrident - 27/2/09 at 07:26 PM

Bottom hose is supposed to be cold especially if the fan has been running.

I take you have a thermostat and bypass circuit plumbed up.

edspurrier - 27/2/09 at 07:28 PM

Thanks. thought so, but it wasn't until I flushed the system. SO just wasn;t working properly before.
Thanks
Ed

nitram38 - 27/2/09 at 07:54 PM

If you plumb your tank correctly, it should have a constant flow through it.
You need two different hose sizes, the larger going to your lowest hose to/from the rad and the smaller going to the hose top rad hose.

SPYDER - 27/2/09 at 11:12 PM

quote:
Originally posted by nitram38
If you plumb your tank correctly, it should have a constant flow through it.
You need two different hose sizes, the larger going to your lowest hose to/from the rad and the smaller going to the hose top rad hose.


I agree with nitram, there should be flow through the header at all times.
Where is the temp switch that controls your fan? In the radiator, in the thermostat housing or in the plumbing somewhere?
If there is facility for a bleed from the top of the rad then connect that to the header tank. If there is a small bleed from the thermostat housing or from a high point on the head then connect that also.
The large hose from the bottom of the header should go to the bottom rad hose.
The header will get quite hot even with only a trickle passing through it.
The bottom hose should definately be hot once the engine is at normal temp, the rad won't cool the water enough to make the bottom hose feel cool. Not in my experience anyway.
Geoff

nitram38 - 28/2/09 at 08:05 AM

Because I have a front rad/rear engine, I have a bleed pipe from the top of the rad and one from the thermostat housing (R1).
The R1 has lots more hoses that I had to combine with the long rad runs. They used to go to the rad too.
It doesn't matter how many small top bleed hoses you have as long as they join together and only one goes into your expansion bottle.
I never had to bleed my car. I just filled up and it ran yesterday. My rad is unusual as it has a chamber at the bottom which is split. Water goes in one side, through half the core up to the top tank and back down the other half of the core and back to the engine.
I had a bleed off put into the top chamber that runs back to the expansion tank.
When the engine ran, no air in the top rad as it was hot.
It takes a bit of thought to get this right. The best thing is to look at a flow diagram in a manual and work out where you are likely to get air pockets forming and take your bleed offs from there.