Blowing water out of the expansion tank
Discussion
Just got the car back from the garage after having a new radiator fitted. Somewhat concerned that the bonnet was open and it being filled up before I drove it home.
About 1/2 way, A big puff of smoke bellowed up the windscreen - Ive seen that before - steam being blown out the expansion tank.
Got it home and theres a small fountin errupting all around the cap. Checked it for tightness, and its well secured.
Aparently it was bled properly, however Im not convinced that it could be that.
Any ideas (please don't suggest blown chg
)
>>> Edited by BlueCerbera on Thursday 1st July 19:08
About 1/2 way, A big puff of smoke bellowed up the windscreen - Ive seen that before - steam being blown out the expansion tank.
Got it home and theres a small fountin errupting all around the cap. Checked it for tightness, and its well secured.
Aparently it was bled properly, however Im not convinced that it could be that.
Any ideas (please don't suggest blown chg
) >>> Edited by BlueCerbera on Thursday 1st July 19:08
Jeez, Chris, I don't think I can help, but I'm in the same boat myself, mate. When my car is hot and I look at the expansion tank it seems totally empty. When I ease the cap off it fills back up again and even bubbles over the top.
Twice in the last couple of weeks I've got stuck in traffic and steam has appeared from that corner. Afterwards I have had to put 1 or 2 litres in to fill it up again and yet, barring any prolonged periods of stationary traffic, it seems to stay at that same level, so a leak appears unlikely.
The temperature guage has given me a few frights aswell, with 100+ sessions not uncommon driving around town in slow-moving traffic. Both fans are cutting in so I'm at a loss. I'm thinking I need an otter switch as a minimum, maybe a new radiator. Maybe there's an air-lock somewhere...
I note from your post that you've just had a new radiator fitted. Was it one of these tri-alloy jobs, or a standard one?
Am going up to the Lake District tomorrow so I'm praying for no jams on the M6 - if there is I think I'm probably doomed to some hard shoulder time at the very least!
Twice in the last couple of weeks I've got stuck in traffic and steam has appeared from that corner. Afterwards I have had to put 1 or 2 litres in to fill it up again and yet, barring any prolonged periods of stationary traffic, it seems to stay at that same level, so a leak appears unlikely.
The temperature guage has given me a few frights aswell, with 100+ sessions not uncommon driving around town in slow-moving traffic. Both fans are cutting in so I'm at a loss. I'm thinking I need an otter switch as a minimum, maybe a new radiator. Maybe there's an air-lock somewhere...
I note from your post that you've just had a new radiator fitted. Was it one of these tri-alloy jobs, or a standard one?
Am going up to the Lake District tomorrow so I'm praying for no jams on the M6 - if there is I think I'm probably doomed to some hard shoulder time at the very least!
Just a standard one. I would have liked one of the fancy new cores, but the warranty company wouldn't step up to the extra cost 
. The RO just called, and he suggested trying to bleed the system with the car on a bit of a slope to get the bubbles up to the top. Time to annoy the neighbours again.
. The RO just called, and he suggested trying to bleed the system with the car on a bit of a slope to get the bubbles up to the top. Time to annoy the neighbours again.Chaps,
May be completely wroing here but, from my searches on the subject ....
If you loosen the expansion tank when hot then the pressure will force water out and more than likely suck air in.
If you try to bleed the system with the engine running, then the same happens.
May help a bit. If I'm teaching Granny to suck eggs then I apologise.
Simon
May be completely wroing here but, from my searches on the subject ....
If you loosen the expansion tank when hot then the pressure will force water out and more than likely suck air in.
If you try to bleed the system with the engine running, then the same happens.
May help a bit. If I'm teaching Granny to suck eggs then I apologise.
Simon
Most conventional cooling systems are plumbed such that releasing the pressure cap causes a blow-back from the pump meaning that what blows out is the best, coolest water in the engine, rather than the steam/crud that is swilling around the heads. In this case, taking the pressure cap off when hot, or having it boil over, is going to make the aeration problem worse rather than better. I assume there is a fill/bleed procedure that covers the engine and the radiator, and you need to find and follow it.
I've not opened the expansion tank while hot. I can see from the side if theres any water left and there wasn't. Theres a nice man coming round this morning to have a go at bleeding the system.
With the cerb, theres 3 bleed points, 2 either side of the engine, and one on the radiator. I thought that you would need to run the engine (not too hot mind), to make sure the water valve is open and that water gets pumped around there system.
Ill extract the procedure from the chappie, and post it up (one for the manual Graham?)
Hopefully it will be just a bleeding problem. Ive only had the car for 2 days over the 4 weeks (stuck in one or another garage), and would really like to drive it
.
With the cerb, theres 3 bleed points, 2 either side of the engine, and one on the radiator. I thought that you would need to run the engine (not too hot mind), to make sure the water valve is open and that water gets pumped around there system.
Ill extract the procedure from the chappie, and post it up (one for the manual Graham?)
Hopefully it will be just a bleeding problem. Ive only had the car for 2 days over the 4 weeks (stuck in one or another garage), and would really like to drive it
.The man has been. Heres the process:
1, Ther car was placed on a slight slope (off side higher)
Take the expansion tank cap off, radiator plug, and loosen the two bleed wing nuts that live under the air boxes (either side of the engine - this should be done with your fingers - not the bolt underneath). He topped the radiator up through the bleed hole, put the plug in and then continued to topped up through the expansion tank.
2, Start the car, and leave run for a bit. Water will start comming out of the two wing nut bleed pipes. Top up the expansion tank, and put the lid on. Let the water flow through for a moment (no bubbles) and then tighten the wing nuts down (near side and then off side). Loosen the one on the radiator, and let air out of that.
3, As the car runs, repeat - loosen near side, and wait for no bubbles, then off side and then finally radiator.
It took about 5 minutes once the car warmed up. Don't assume that its properly blead the 1st time the water runs without bubbles, more will surface.
Wait for the car to cool down fully, and top up the expansion tank.
If your not in a rush, its probably worth repeating once more. (just bit 3, as otherwise air may let air back in).
A pair of gloves may be a good idea, and the man cooked his fingers a bit.
Ill give it a good run tonight, and we will see how we get on.
1, Ther car was placed on a slight slope (off side higher)
Take the expansion tank cap off, radiator plug, and loosen the two bleed wing nuts that live under the air boxes (either side of the engine - this should be done with your fingers - not the bolt underneath). He topped the radiator up through the bleed hole, put the plug in and then continued to topped up through the expansion tank.
2, Start the car, and leave run for a bit. Water will start comming out of the two wing nut bleed pipes. Top up the expansion tank, and put the lid on. Let the water flow through for a moment (no bubbles) and then tighten the wing nuts down (near side and then off side). Loosen the one on the radiator, and let air out of that.
3, As the car runs, repeat - loosen near side, and wait for no bubbles, then off side and then finally radiator.
It took about 5 minutes once the car warmed up. Don't assume that its properly blead the 1st time the water runs without bubbles, more will surface.
Wait for the car to cool down fully, and top up the expansion tank.
If your not in a rush, its probably worth repeating once more. (just bit 3, as otherwise air may let air back in).
A pair of gloves may be a good idea, and the man cooked his fingers a bit.
Ill give it a good run tonight, and we will see how we get on.
An amazing amount of tiny air bubbles are trapped in the new radiator and I would always recommend re-bleeding the system after say the first 20 or 30 miles...I bet you can put about a pint of coolant in even if it was initially carefully bled.
>> Edited by Toffer on Friday 2nd July 11:27
>> Edited by Toffer on Friday 2nd July 11:27
Well, that's interesting stuff. I keep opening the cap to see what's happening, and filling up with more coolant. From what you say, it seems I might just be making the problem worse - letting air in and adding to the air locks. Hmmm... Trouble is, when it comes to car mechanics I don't know my arse from my elbow.
Anyway, the old girl is on the way to Topcats next week so spect they'll suss it out for me.
Anyway, the old girl is on the way to Topcats next week so spect they'll suss it out for me.
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