# Bubbles in expansion tank



## jlagnese (Feb 14, 2002)

After my car has been running and turned off there is a bubbling into the expansion. The head gasket looks fine, Compression were all 155 psi and one near 180. Not sure what is the cause. Anyone have experience with this?


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## jlagnese (Feb 14, 2002)

*More info*

Patient is a 2004 Passat GLX 6 cylinder with 83,999 miles.


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## garryt (Dec 22, 2016)

start iut from cold with the expansion tank cap off and check for bubbles rising from the bottom of the tank first:thumbup:


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## jlagnese (Feb 14, 2002)

*bubbles*

If I run the car for a minute it gurgles from the lower hose.


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## garryt (Dec 22, 2016)

going to need more info. have you changed the coolant recently? does it lose much coolant? has the engine overheated at all? 180 seems a bit high when the other 5 are only 155. pull that plug out and check the piston crown with a small torch. if it is spotless clean, that's not a good sign:facepalm:


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## jlagnese (Feb 14, 2002)

The timing belt was changed. I have only put less than 200 miles on it. The oil and coolant was changed. The coolant was tested for combustion gasses and none. Coolant level is okay. Oil was low when I got it. No brown foam on the dipstick.


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## garryt (Dec 22, 2016)

I would leave be for now. just keep at eye on levels. still curious why one pot would be 25 psi higher than the rest though


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