Puzzling over heating issue!

[will3232]

I have a very weird overheating issue on my williams. Wondered if anyone on here could help.
i have recently had to start bridging out my fan switch to make the fan on my car run constantly. All hoses feel warm when the car warms up, although the there is no obvious coolant flow in the header tank. The car cools down quite quickly when you are stopped or stuck in traffic but when you are driving the car gets to the third bar on the temp gauge? Has anybody else experienced this before? Not sure wether it's a water pump, a rad or just a thermostat? I fitted a new coolant cap as the old one was leaking but water comes out of the coolant cap when pressure has built up?

Sorry for for the essay just trying to give everyone the full picture!

thanks in advance
Will

[katbloke]

Does the heater work? Might be an air lock

[will3232]

The heater works intermittently, how would I clear an air lock if I have one?
thanks
Will

[katbloke]

There's a bleed screw top of rad think passenger side cap off expansion tank

[16v_paddy]

Sounds more like the heater matrix is full of crap causing an air lock especially if the heater isn't always working

[will3232]

Should I bypass the heater matrix then to see if that solves it? Then if it does I know I need to replace it?
Thanks again
Will

[katbloke]

System flush through both pipes of expansion tank would get rid of crap

[will3232]

I ran a coolant flush through about 6 months or so ago. It didn't seem to achieve too much. Should I try again?
thanks again
Will

[katbloke]

A brown expansion tank would indicate state of coolant I ran a host through mine both ways u til it ran clear then refilled with type d( I think) and to this day u til engine removal the coolant stayed green also went for a low temp fan sensor to kick the fan in at lower temperature

[will3232]

My expansion tank was brown, that's why I flushed the engine the first time. Maybe it needs redoing?
Thanks
Will

[katbloke]

Try a bleed first

[katbloke]

When bleeding engine has to run heater on full heat expansion cap off and undo rad bleed screw till only water comes out then run car till fan kicks in that should be it then

[Vandella]

may still be an idea to give it a good flush through.. empty..flush it thru with a hose.. fill it up with water... get the engine warm so the fan kicks in.. flush through again.. get some cheap coolant and fill it up.. go for a drive or let it warm up again.. flush out with water.. fill up with what ever coolant u use.. and as an indicator..or so u can see clearly.. get a new header tank too... then just keep and eye on the colour.. dont have to do it that many times.. can do it more depending on how bad it is...
http://www.ebay.co.uk/itm/RENAULT-CLIO-2-0-16V-WILLIAMS-MARK-1-ONE-HEADER-EXPANSION-TANK-COOLING-BROWN-CAP-/161193539765?pt=LH_DefaultDomain_3&hash=item2587e238b5

[16v_paddy]

The cheap & nasty coolant trick is by far the best way I've been able to flush out crap from the system on these cars :winkey:

[will3232]

Ok that's great, thanks very much guys :). Any chance that might clear the heater matrix if it's blocked?
Thanks again
Will

[16v_paddy]

It's entirely possible as whatever is in the cheap nasty stuff seems to dislodge all sorts of crap even after flushing the system with hose pipes, running up to temp with normal water twice then with type d ( which went manky pretty quick) then with normal water 1 more time, which when up to temp was perfectly clear.

If it helps, I just went to a local factors & asked for 5 litres of the cheapest nastiest shit they had, no idea what brand but it was dark blue