Gurgling from the cooling system

[nicka]

After 20 minutes+ of driving a 'gurgling' noise can be heard when the car is stopped or in traffic coming from the overflow tank.

The coolant level seems to still be O.K, and there is no leakage from the water pump etc. The water in the overflow tank is not discoloured or the exhaust emmiting white smoke that would normaly mean a blown head gasket. Has anyone else had this problem, and more importantly how did you fix it?!

[johno]

Nick,

You shouldn't have any water in the overflow tank !?! If you have it suggests the system is boiling over and 'overflowing' into the tank, unless it is old water from a previous boil over or someone has tried to fill the system from the overflow....

Are you chacking the water level in the swirl tank or the overflow ??

Check out the thread below and see where thia will all lead.....

www.pistonheads.net/gassing/topic.asp?t=5642&f=11&h=0

Sounds like the system is low on water and you can hear air in the system that shouldn't be there. It may just be the noise of the coolant flowing, but I doubt it.

Cheers

Mark

[GreenV8S]

quote:
Nick,

You shouldn't have any water in the overflow tank !?! If you have it suggests the system is boiling over and 'overflowing' into the tank, unless it is old water from a previous boil over or someone has tried to fill the system from the overflow....

Are you chacking the water level in the swirl tank or the overflow ??

Check out the thread below and see where thia will all lead.....

www.pistonheads.net/gassing/topic.asp?t=5642&f=11&h=0

Sounds like the system is low on water and you can hear air in the system that shouldn't be there. It may just be the noise of the coolant flowing, but I doubt it.

Cheers

Mark

Oh no, are we heading back into the troublesome question of which cap should be on which tank? Go on Nick, spill the beans, which way round are they on yours? Judging by last time this cam up, half the people will tell you that's the problem right there, the other half will say that rules *that* out then.

Cheers,
Peter Humphries (and a green V8S)

[nicka]

I've checked the swirl tank, and the level seem s to be O.K, in the overflow there is water sitting at the 2nd ridge when the engine is cold. I'll have anothere look in daylight, thanks.

[PetrolTed]

I've had this for a couple of years now. Still does it despite a recon rad a few weeks back and after I flushed the system in the summer. Only had one spate of actually overheating though which was solved by the flushing (and getting the caps the right way around).

[vodkakid]

i have my cap the right way round but i have to bleed the system every couple of weeks cause air gets in and the swirl tank over flows even though it has a new cap on

[Dave_H]

I always have my cap on backwards, normally with the volume and bass up high.

Oh, sorry thought I was on the Saxo VTR forum

[woody]

Er now i'm confused (not difficult), let me explain. I recently swapped my caps over (pressure cap now on swirl tank and non-pressure on expansion/overflow) made sure swirl tank was full(ish) went for a blast and when stopped could see and hear a bit of steam - passing pressure cap and dribbling down swirl tank. When cold level in swirl tank had dropped about 1.5 inches, and expansion/overflow tank had lots of water in it. Only dribbled and hissed once mind - pressumably until there was an air gap at the top to allow expansion?

Previously with caps other way round swirltank stayed full and expansion/overflow would dump most of contents onto floor, leaving just a bit in the bottom.

Which is the right way, and what exactly should there be in each tank ????

A very Chris

P.S had new Rad last April.

[GreenV8S]

quote:could see and hear a bit of steam - passing pressure cap and dribbling down swirl tank.

This seems to suggest the pressure cap is no good? The pressure seal should be sealed tight until the blow-off pressure is reached, then anything that blows past it is vented into the overflow catch tank. The top seal on the pressure cap should prevent anything coming out the top even if it is blowing off. So if you have steam coming out the top of the swirl tank that outer seal of the pressure cap can't be doing its job. When you replace it, make sure both sealing faces on the top of the swirl tank are clean. If it's had a blank cap on in the past, it's possible the lower face that the pressure seals normally seals against has become dirty/corroded and the system isn't holding pressure. In which case it will spit water and steam all over the place once it gets hot.

Hope this helps,
Peter Humphries (and a green V8S)

[johno]

I'm not getting involved in this saga again !!!

Mine works !!! I've had enough of pressure caps to last a lifetime !!!!!!!

[markbigears]

ive just find the overflow tank up to the level it says
on the side of the tank? so are we saying NO fluid should be in there? so why does it say min level on the side? me very confused! mark....got my new caps though....£12 quid from waldonway for the 2

[johno]

The overflow tank on the S is taken from a n other car. Probably the Sierra. On whatever car it was on it was probably where you filled the cooling system from and therefor the necessity for Min and Max markings. If I find water in my expansion tank it signifies a problem that the car has overheated ad blown out coolant.

Therefor I suggest that you shouldn't have any water in the expansion tank as it may disguie when you have had a problem.

Cheers

Mark

[mhibbins]

You should have no water in the expansion tank at all, it isn't really an expansion tank, just an overflow tank. As the pressure cap is on the swirl pot the only way water can get into the white tank is if the pressure in the system exceeds the rating on the pressure cap. Water certainly won't be able to find its way back in from the overflow to the swirl pot.

My swirl pot level is always about 2 inches from the top. I've tried topping it up but it just chucks it out so I've left it at that. It never overheats even when stuck on the M4.

Mark

[markbigears]

2 inches from top.....well thats good to know, i'd always topped it up to the top and it would spit it out.......so no water in the overflow tank, i'll drain it back out now! cheers guys....learning all the time!

[woody]

Now very confused.... there should be no coolant in the expansion/overflow tank?, so why does it say in the S hand book that - "..under all conditions the reservoir tank (swirltank?) should be completely full. The reservoir overflow bottle should be 1/2 full when cold"

Very Chris

P.S. my hand book also states that the reservoir tank has the pressure cap on. Also very confusing as it refers to both tanks withabout three different names each... Plain english eh...

[GreenV8S]

quote: Also very confusing as it refers to both tanks withabout three different names each... Plain english eh...

... and I expect that was written by the bloke that designed the cooling system, which probably explains a lot! The good news is that's the best he's done. The bad news is that's the best he's done.

Cheers,
Peter Humphries (and a green V8S)

[Dave_H]

Chris,

I'm the same as Mark and Mark, nothing in the expansion tank, just keep the pressure cap on the swirl tank, and check the swirl tank for the water level.

Like Mark (Johno) said, the expansion tank came from another car, so the Min/Max mark means nowt.

Cheers,

Dave.

[mhibbins]

Also, I can't see how it's possible for water to get from the plastic tank to the swirl tank. The only route it can go through is down past the pressure cap on the metal swirl tank. The only time that is open the pressure will be forcing air and water back out anyway. So what's the point of it at all?

Mark

[mhibbins]

quote:... and I expect that was written by the bloke that designed the cooling system,

Designed... with their reputation... are you sure?

[nicka]

Thanks to all who replied - the 'gurgling' problem appears to have been solved by swapping around the swirl tank cap with the overflow tank cap. Looks like at some point someone has put them back the wrong way round, I used some gasket sealer on the caps for good measure.

I've noticed that the temperature indicator sits at 95% as its constant temperature after the engine has warmed up, a foulty indicator perhaps? It also seems to rise by 10 degrees whenever I turn the panel backlights on, very strange!