bubbling noise - please help

[voo51 0]

I need a Bit of help on the header tank please!I have a polished one with no level indicator on. How do you know how much to fill it up to? And what happens if you fill it too much? As I have a slight hissing coming from it and it has dribbled some coolant down the back of it. I wonderedif I had put too much in and the pressure is releasing it. Or, if my cap is knackered! It has a mk2 golf cap on.

:help:

[Jim 2]

Have you got a blue or black expansion tank cap? If it's black, you need rid of it for a blue type one..

[voo51 0]

It's a blue one. Once hot it was continually hissing, then once cooler it was hissing now and then . It's now been 5 hours and only makes a slight hiss when i jiggle the tank. Maybe it's too full and with heat the pressure builds up and releases through a valve in the cap?

[KIPVW 0]

It's a blue one. Once hot it was continually hissing, then once cooler it was hissing now and then . It's now been 5 hours and only makes a slight hiss when i jiggle the tank. Maybe it's too full and with heat the pressure builds up and releases through a valve in the cap?

 

 

You are probably right there Laura, take a peek in the morning when its stone cold to see where the level is, does it still have a sender/warning sensor attached to let you know the level is low too? not sure on these alloy things so just curious as if it does then i'm sure it'll flash the light if the cooland is too low. :wink:

[voo51 0]

When I got to work this morning, the tank was not hissing anymore, but coolant had dribbled down the rear of the tank. I have just checked it again and there is no hissing and the tank hasn't stayed as hot for as long as yesturday. Plus, I took the lid off and gave it a wiggle to confirm the valve is rattling and so still working. I think I must have just filled it too high and the excess has now been expelled. Guess I will see when I get home!!

[voo51 0]

Right, the coolant tank continued to leak coolant and hiss. I have now replaced the cap and it seems to have stopped. However, when I turn the engine off you can now hear it bubbling/boiling. Is this normal? As I havn't heard it before and I am meant to be going Vagfest tomorrow!! :(

[G-polž 0]

Try open the heating in the car before you ad colig loqid or wather to let the air that migth be traped in heater core.

[voo51 0]

I think I have the mother of all air locks in the system from when I changed the header and topped up the system. I have just started it from cold with the cap of and worked the two radiater pipes. At first, when I sqoze the top one it took ages to get back to shape, as if an air lock in there. Then when I sqoze the bottom one the top one would suck in. After a while of working both, the top one would reform straight away and when the lower one squeed the top one would stay in its shape. I also kept the heaters on full wak.once the fan kicked in I took it for a drive, stopped, turned off the engine and no noise. I returned home to my hilly drive to find when I turned it off the bubbling was back. I squoze both pipes and they seemed fine, however, the header lid was releasing pressure. I then took the lid off and gave some more squeezes when huge gulps of air came out the tank. I replaced the lid, went for another drive, pulled up on a hill, no bubbling. Returned home, pulled up, bubbling again and pressure from the lid. I cannot carry on anymore as my boyfriend is moaning at me for it running and apparently ' rattling the windows' and disturning the naighbours, so if I break down tomorrow, I break down!! :mad2:

[KIPVW 0]

Hmm would have thought it is just an air lock then Laura so keep running it with the cap off to see if it clears. not really sure other than that but may be worth taking some coolant & water if you go on a bit of a trip anywhere.

 

Keep a constant eye on the temp guages too.

[Erny 0]

Is it a valver by anychance? There a pain fir airlocks, On ya drive or on ya street, take the header tank cap off, open the heaters to hot, and run the car on the spot, rev it alittle to help warm up faster, let it bubble over, keep squeezing pipes ere and there but be careful as to not burn yaself, untill the fan kicks in, switch the engine off and leave it cool with the header tank cap off. make yasen a cuppa n come back after eastenders, Top up to were u feel nessecary cap on should be good to go, I hope

[pagurus 0]

Hi - sounds like an airlock / lazy thermo - no idea, but just had identical problem and sorted it -

Posted the same info for iMation too ...

http://the-corrado.net/.archive/forum/viewtopic.php?f=1&t=94860

"Just had this exact problem after major refurb in the engine bay. Car was stood (sans oil and water), for three months or so. When I finished the engine bay rebuild, I let it run then after 5-10 mins, clunking, bubbling noises then the expansion bottle bubbling over. Drained the system again, same problem. Went through the cycle again, same result. Panicking it was the water pump :pale: . This time pulled the top hose between the water pump and engine block. Guess what, bone dry :brickwall: Also, the bottom hose was cold like yours :shock: .So got a funnel and filled the hose routed directly into the water pump. Water then started running out of the black plastic engine block junction. Re-attached the hose. Filled the system again then went for a drive with a 5 litre botle (engine oil container well flushed), of water just in case. En-route, I made sure to stop the engine whenever I was standing still for more than a few seconds. The out and return journey was about 35 miles. I kept up with the 'stop engine' regime till I got home, and then stood the car on my driveway with the bonnet up and engine running, holding my breath. The fan was kicking in at about 105% oil temp, and guess what, no more boil over. My water pump was replaced in 2006, and it wasn't making any noise(like it did when it failed), so I prayed it was not that. Seems to be fine now :clap: . Perhaps it's something about the components soaking in water for a while before they start working properly, i.e - the thermostat. Sure glad this sorted itself out. Hope this is helpful for ya :D"