Water Coming Out Of Expansion Cap

[carlo6265]

Hi can anyone please help I have a 2002 Galaxy 1.9TDI which has covered nearly 100,000 miles when I bought the car about a 1.5 years ago I had the timing belt , water pump and thermostat replaced all was well untill about 5 months i noticed that there was water around the expansion cap so I replaced the cap on the bottle but still the poroblem there. The enginge does not overheat the temp gauge sits at 90 all the time. I park the car overnite on the drive and cheak the water when cold and I can see that the water has dropped to the min mark but as i undo the pressure cap the water rises and a load hissing noice occurs.

 

Can Anyone please help with this problem

[seatkid]

I find all the VAG cars I've owned the water always vents until it drops to the min mark.

 

So it sounds normal, dont bother topping up much above the min level.

 

The rising/hissing is just releasing the pressure and shows the cap is doing its job and you dont have a leak (when cold).

 

Only get concerned if the level drops more than a couple of cm below the min mark.

Edited March 5, 2011 by seatkid

[carlo6265]

I find all the VAG cars I've owned the water always vents until it drops to the min mark.

 

So it sounds normal, dont bother topping up much above the min level.

 

The rising/hissing is just releasing the pressure and shows the cap is doing its job and you dont have a leak (when cold).

 

Only get concerned if the level drops more than a couple of cm below the min mark.

[carlo6265]

Hi thank you for that I do check the water level on a daily basis and I tend to dry around the expansion cap take the galaxy out for run come back and there is water around the cap again.

 

Would you recommend getting a pressure test done on the head to see if the head gasket has gone.

[chrispb123456]

Hi thank you for that I do check the water level on a daily basis and I tend to dry around the expansion cap take the galaxy out for run come back and there is water around the cap again.

 

Would you recommend getting a pressure test done on the head to see if the head gasket has gone.

Hi there

If you say the level had been OK and no pressure in the system when cold, and now over the last few months is showing signs of losing water and still under pressure when cold I would say you have early signs of gasket failure, or cylinder head has cracks.

 

The rise in pressure when the engines hot will return to zero when cold there should be no gurgling or hissing when cold.

[carlo6265]

Hi no that's not the case when we bought the galaxy from the garage the first thing we had fhe timing belt and water pump after a few months I noticed that the bottom hose

 

 

The bottom hose was not getting hot so I asked a mate who works at fords and he adviced to change the thermostat although I had heating in the car was ok so anyway he came round changed the thermostat and the water starting coming out of expansion when the vehicle had been driving but if i leave the car for a couple of days not using it I check the water which is no the min mark and as i undo the pressure cap the water rises to the max mark and I can see water/antifreeze in the battery tray.

[seatkid]

Hi no that's not the case when we bought the galaxy from the garage the first thing we had fhe timing belt and water pump after a few months I noticed that the bottom hose

 

 

The bottom hose was not getting hot so I asked a mate who works at fords and he adviced to change the thermostat although I had heating in the car was ok so anyway he came round changed the thermostat and the water starting coming out of expansion when the vehicle had been driving but if i leave the car for a couple of days not using it I check the water which is no the min mark and as i undo the pressure cap the water rises to the max mark and I can see water/antifreeze in the battery tray.

 

1. The bottom hose rarely gets warm as a Tdi is so efficient it doesn't produce much waste heat. Only in hot weather and/or high speed/load does the radiator get hot to the extent that bottom hose is hot. So if the temp gauge is showing normal there is nothing to worry about. Probably you changed the thermostat for no reason.

 

2. Don't keep topping up! As I said unless the level drops way below minimum (i.e 1 - 2cm below, then top up to halfway between min and max) - when the engine heats up, the coolant expands/rises and anything above max level is thrown out. Check your level when the engine is cool and after you released any pressure. Its normal for some residual pressure to remain when the engine cools and releasing this causes the level to rise as there are a lot of flexible rubber water hoses about in the Shalaxy.

 

With faulty gasket/ cracked head usually you would lose lots and lots of water and there would be obvious signs of overheating (running way hot on the temperature gauge and a hot radiator/bottom hose)

[FLENG]

i had exactly the same problem

from my experiences i would say head gasket

 

only way to be sure to get a sniffer test

dont get the cheap one that just push's on the expansion tank, there is a snap on tester that screws to the expansion tank this is will tell you if there are gases in the coolant, takes about 15mins and is very accurate

the other sniffers are useless, i had 3 of them done after doing all the obvious things first and all came back negative