Cooling System: blowing from the filler bottle
Discussion
My 2000 4.5 LW has learned a new trick. In the usual London grid-lock traffic, the Cerb heats up and I get steam blowing from the coolant reservoir. I understand that the reservoir cap is designed to let excess pressure/steam escape, but I'm concerned! Is this normal?
It only happens when I am literally crawling along in traffic jams (which is every day in London).
* Does anyone else experience this?
* Is it "normal"?
* Is there a problem with my cooling system?
* I have read about mods that can help the system run cooler, or have the fans come on sooner (or something like that) - any ideas?
It's more than a little disconcerting to be sitting in stationary traffic with steam blowing out of the reservoir onto the windscreen!
Cheers,
Gixxer
It only happens when I am literally crawling along in traffic jams (which is every day in London).
* Does anyone else experience this?
* Is it "normal"?
* Is there a problem with my cooling system?
* I have read about mods that can help the system run cooler, or have the fans come on sooner (or something like that) - any ideas?
It's more than a little disconcerting to be sitting in stationary traffic with steam blowing out of the reservoir onto the windscreen!
Cheers,
Gixxer
Had a similar problem, Joolz advised me to check that the system is fully bled of air. If you let any air into the system, eg. by allowing the water level to drop too low, it can take 5-6 bleeds to purge it - waterways are wonderful air traps 
. Once air is in, irrespective of top-ups, everytime it warms up too much (sitting in traffic for example) the trapped air will tend to push some water out.
Bleed Process
Not sure on a 4.5, but on 4.2 there are 2 bleed screws, one on each side water rail and a bolt on the o/s of the top of the radiator.
1) Top up water to full level of header bottle, then loosen each of the bleed points and retighten when water appears(like bleeding a home radiator).
2) If you can reach any of the water hoses give them a repeated rapid squeeze to move further air to high points.
3) Repeat 1) to see if any more air has appeared at the bleed points
4) Top up water again and refit cap
5) run engine up to warm (spin round the block
, any excuse)
6) Allow to cool then back to 1) and repeat
7) continue until no further air appears, then check again in a week or two.
Check water level daily and don't forget to include anti-freeze in your top-ups.
Bits like this will start to appear in the tech section of Grahams TCR site soon (once we get our heads together
)
>> Edited by suffolkfox on Sunday 1st February 00:11
. Once air is in, irrespective of top-ups, everytime it warms up too much (sitting in traffic for example) the trapped air will tend to push some water out. Bleed Process
Not sure on a 4.5, but on 4.2 there are 2 bleed screws, one on each side water rail and a bolt on the o/s of the top of the radiator.
1) Top up water to full level of header bottle, then loosen each of the bleed points and retighten when water appears(like bleeding a home radiator).
2) If you can reach any of the water hoses give them a repeated rapid squeeze to move further air to high points.
3) Repeat 1) to see if any more air has appeared at the bleed points
4) Top up water again and refit cap
5) run engine up to warm (spin round the block
, any excuse) 6) Allow to cool then back to 1) and repeat
7) continue until no further air appears, then check again in a week or two.
Check water level daily and don't forget to include anti-freeze in your top-ups.
Bits like this will start to appear in the tech section of Grahams TCR site soon (once we get our heads together
) >> Edited by suffolkfox on Sunday 1st February 00:11
You can also get this problem if the cap is a bit iffy or if the system is overfilled.
As for the bleeding thing... don't forget to bleed the rad as well as that tends to trap the air. I would get the engine hot not a simple trip around the block so that the thermostat is open. If you don't do that then the engine can be bleed but the first time that the stat opens, trapped air from the rad undoes all the good work.
As for the bleeding thing... don't forget to bleed the rad as well as that tends to trap the air. I would get the engine hot not a simple trip around the block so that the thermostat is open. If you don't do that then the engine can be bleed but the first time that the stat opens, trapped air from the rad undoes all the good work.
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