Cooling System question V12VS
Discussion
When I bought my car I had a problem with the radiator cap which meant that the cooling system wasn't pressurising. I bought a new (Expensive) cap and the system came up to pressure well, no more coolant leak into the expansion tank - happy days. However I've notice that when the car is cool that the front left coolant hose becomes 'sucked in' and narrows to less than half its pressurised diameter. Is this normal or do I have some sort of airlock in the system?
When I open the coolant header tank the water level looks normal but the coolant hose remains compressed.
If someone wouldn't mind checking theirs I'd be most grateful! Thanks
I don't appear to be overheating, have done several 2+ hour drives over the last few months.
When I open the coolant header tank the water level looks normal but the coolant hose remains compressed.
If someone wouldn't mind checking theirs I'd be most grateful! Thanks
I don't appear to be overheating, have done several 2+ hour drives over the last few months.
Edited by CatalystV12V on Sunday 9th June 18:32
LTP said:
Not a V12V owner but I've never seen that. When the hose is collapsed, I assume if you crack the coolant cap it sucks air in and the pipe expands to its normal circular section?
No it doesn't return to 'regular' diameter.. just stays the same.. When in use it gets hot and expands to 'normal' size. CatalystV12V said:
No it doesn't return to 'regular' diameter.. just stays the same.. When in use it gets hot and expands to 'normal' size.
So with no cap on at all it stays collapsed? And was it doing this before you changed the cap?The usual explanation I understand is that the cooling system is developing a vacuum as it cools, which collapses the hose. This is usually for one of two reasons: the return valve in the radiator cap is faulty, so it allows excess coolant to pass into the expansion tank when the engine is hot and the coolant volume expands, but it won't allow it to pass back through the cap when the engine cools and the coolant volume decreases, or; the breather of the expansion tank is faulty, so it allows air out when hot coolant flows in, but won't allow air back in when the coolant cools, thus creating a vacuum.
The only other thought I can offer is somehow your hose has now taken a "set" at ambient temperature and that's the shape it wants to be, but it gets blown up like a balloon as the system pressurises and so becomes circular. I find it difficult to believe the V12 cooling system would allow a vacuum to exist in the hose when there isn't a radiator cap on.
LTP said:
So with no cap on at all it stays collapsed? And was it doing this before you changed the cap?
Thats correct, it stays collapsed. I don't know if it was doing it before as initially I had a different problem. When I bought the car and got it home I could smell antifreeze. And the coolant level was dropping as it was dumping in to the Coolant overflow which I was told is behind the nearside wheel liner. My local indy suggested changing the cap as this was likely the problem. Since change coolant loss has stoped but I noticed the pipe compression.
I'm guessing that if the system was compromised or 'locked' I would get an overheat warning - but the temp gauge rises gradually and stays bang in the middle.
It didn't overheat with the old cap either, but you could compress the coolant pipes with your hand. Being careful not to burn yourself.
I think your idea of it being 'set' might be on the right track..
Caslad said:
My (2010) DBS does the same. I don’t know if it’s normal or not but it’s going in for some minor issues next week so I’ll ask.
Good to know. Mines in for a service in 4 weeks time.. but I’ve got a couple of trips planned before then, so would be interested to hear what they say. CatalystV12V said:
LTP said:
So with no cap on at all it stays collapsed? And was it doing this before you changed the cap?
Thats correct, it stays collapsed. I don't know if it was doing it before as initially I had a different problem. When I bought the car and got it home I could smell antifreeze. And the coolant level was dropping as it was dumping in to the Coolant overflow which I was told is behind the nearside wheel liner. My local indy suggested changing the cap as this was likely the problem. Since change coolant loss has stoped but I noticed the pipe compression.
I'm guessing that if the system was compromised or 'locked' I would get an overheat warning - but the temp gauge rises gradually and stays bang in the middle.
It didn't overheat with the old cap either, but you could compress the coolant pipes with your hand. Being careful not to burn yourself.
I think your idea of it being 'set' might be on the right track..
Following Gilbo500’s pearl of wisdom I took the expansion tank cap off and depressed the little brass disc on the underside of the cap half a dozen times using a Philips head screwdriver. There’s clearly a spring inside the cap which returns the disc to position after it’s been depressed so this valve mechanism appears to be working.
Next with the cap off the expansion tank I massaged the collapsed coolant hose back into shape and this was accompanied by some gurgling noises from the expansion tank so clearly this manoeuvre released some air from the cooling system.
I’ve run the car up to temp and let it cool back down and the hose has not collapsed again so either expelling the air or fiddling with the cap valve seems to have done the trick, temporarily at least.
Next with the cap off the expansion tank I massaged the collapsed coolant hose back into shape and this was accompanied by some gurgling noises from the expansion tank so clearly this manoeuvre released some air from the cooling system.
I’ve run the car up to temp and let it cool back down and the hose has not collapsed again so either expelling the air or fiddling with the cap valve seems to have done the trick, temporarily at least.
Caslad said:
Following Gilbo500’s pearl of wisdom I took the expansion tank cap off and depressed the little brass disc on the underside of the cap half a dozen times using a Philips head screwdriver. There’s clearly a spring inside the cap which returns the disc to position after it’s been depressed so this valve mechanism appears to be working.
Next with the cap off the expansion tank I massaged the collapsed coolant hose back into shape and this was accompanied by some gurgling noises from the expansion tank so clearly this manoeuvre released some air from the cooling system.
I’ve run the car up to temp and let it cool back down and the hose has not collapsed again so either expelling the air or fiddling with the cap valve seems to have done the trick, temporarily at least.
I've just attempted the same. Rather than gurgling noises, my attempt was accompanied by a 'sloshing' sound but the hose refused to return to 'normal'. For good measure I also compressed teh hose on the other side of the block. Same sloshing sound from expansion tank. So it would seem my hose is 'set' in that shape and coolant appears to be moving around ok.. Next with the cap off the expansion tank I massaged the collapsed coolant hose back into shape and this was accompanied by some gurgling noises from the expansion tank so clearly this manoeuvre released some air from the cooling system.
I’ve run the car up to temp and let it cool back down and the hose has not collapsed again so either expelling the air or fiddling with the cap valve seems to have done the trick, temporarily at least.
Hello
change your cap again...
here at a good price.
I've had it for 2 years without problems!
Quinton Hazell FC527
https://www.oscaro.com/bouchon-reservoir-de-liquid...
change your cap again...
here at a good price.
I've had it for 2 years without problems!
Quinton Hazell FC527
https://www.oscaro.com/bouchon-reservoir-de-liquid...
Edited by Phil57DBS on Friday 14th June 09:49
Caslad said:
Following Gilbo500’s pearl of wisdom I took the expansion tank cap off and depressed the little brass disc on the underside of the cap half a dozen times using a Philips head screwdriver. There’s clearly a spring inside the cap which returns the disc to position after it’s been depressed so this valve mechanism appears to be working.
Next with the cap off the expansion tank I massaged the collapsed coolant hose back into shape and this was accompanied by some gurgling noises from the expansion tank so clearly this manoeuvre released some air from the cooling system.
I’ve run the car up to temp and let it cool back down and the hose has not collapsed again so either expelling the air or fiddling with the cap valve seems to have done the trick, temporarily at least.
Quick update. My fix was indeed temporary & the collapse of the hose returned.Next with the cap off the expansion tank I massaged the collapsed coolant hose back into shape and this was accompanied by some gurgling noises from the expansion tank so clearly this manoeuvre released some air from the cooling system.
I’ve run the car up to temp and let it cool back down and the hose has not collapsed again so either expelling the air or fiddling with the cap valve seems to have done the trick, temporarily at least.
The tech at the MD suggested a new cap may be worth a try but recommended a flush and fresh coolant as apparently there can be a build up of sludge which can affect some parts of the cooling system.
Caslad said:
Caslad said:
Following Gilbo500’s pearl of wisdom I took the expansion tank cap off and depressed the little brass disc on the underside of the cap half a dozen times using a Philips head screwdriver. There’s clearly a spring inside the cap which returns the disc to position after it’s been depressed so this valve mechanism appears to be working.
Next with the cap off the expansion tank I massaged the collapsed coolant hose back into shape and this was accompanied by some gurgling noises from the expansion tank so clearly this manoeuvre released some air from the cooling system.
I’ve run the car up to temp and let it cool back down and the hose has not collapsed again so either expelling the air or fiddling with the cap valve seems to have done the trick, temporarily at least.
Quick update. My fix was indeed temporary & the collapse of the hose returned.Next with the cap off the expansion tank I massaged the collapsed coolant hose back into shape and this was accompanied by some gurgling noises from the expansion tank so clearly this manoeuvre released some air from the cooling system.
I’ve run the car up to temp and let it cool back down and the hose has not collapsed again so either expelling the air or fiddling with the cap valve seems to have done the trick, temporarily at least.
The tech at the MD suggested a new cap may be worth a try but recommended a flush and fresh coolant as apparently there can be a build up of sludge which can affect some parts of the cooling system.
I’m no expert , but I find it hard to believe that our cars suffer from sludge build up.
My car has only covered 18k mile, and I’ve just checked the service history and it’s never had a coolant change. Better add it to the list.
Gassing Station | Aston Martin | Top of Page | What's New | My Stuff