Coolant consumption I bought a brand new golf 2006. it has now 20 k on odo. an it consumes all the coolant within 1 week. checked all cooling system for leakage but found none.engine runs correctly no overheating.

oil in the cooling system is an oil cooler in the radiatro failure
fix is new radiator
oil in a cooling system leads to overheating as it prevents the water from contacting the cylinder walls to transfer the heat
The system will have to be flushed professionally to fix the problem
have a compression test doen to check for head gasket problem as well

Since you recently bought this car, did the seller inform you that the car had a problem? If they didn't and knew there was a problem (and 1-2 quarts a week oil consumption is something they would know) that is fraud.

Did you have oil residue on your plugs when you pulled them out and checked them? Which cylinders did you have the oil residue if any?

If you are burning 1-2 quarts of oil a week your tail pipe should be black if not oily. Is your car smoking badly? Have you considered doing a compression check to find out the health of your engine? I would if I was in your position.

Although you seem to be the handy type of guy, rebuilding an engine is not for the light hearted without a thorough mechanical background. Depending on your knowledge base and tool inventory and rebuilt engine might be the way to go.

Who told you to replace the entire engine??? -An engine salesman? You should take advice with caution especially if the advisor stands to benefit. To fix overheating, try putting in a new thermostat. The new thermostat and gasket should cost you less than 20 bucks. Make sure your cooling fans cut on when the engine is warmed up. If not, then check the fuses and relays to the fans. Double check your coolant level. Your oil consumption is perfectly normal.

P2181 - Performance Malfunction in Cooling System
Possible Solutions
* Check Engine Coolant Temperature Sender (G62)
* Check Coolant Thermostat
* Check Engine Cooling System
o Put the key on, fan speed on 1, and push the a/c switch. Are both fans kicking on? If not, you found the problem.
o Put the key on and fan speed on 1. Does heat come out readily from the vents?
+ No. Probably the water pump is gone.
+ Yes. Probably the thermostat is gone. good- luck!!

Is the heater nice and hot when the needle shows low temp? If the cooling fans turn on and the heater is hot, that leads me to believe the coolant temperature sensor is bad. You should try replacing that sensor. They are only $6 usd here. As long as your check engine light is not on and your fans are running, this will not hurt your car... but this is something you should fix soon if you can. Make sure the engine is cold when you replace the sensor

Level of engine output is not related to water consumption at all, you are not doing anything wrong. It's too soon after the leaking radiator to assume that the engine is consuming water. .4 liter is not much to add at all. Some engines hide air pockets within them and it takes weeks to purge all the air out of the sealed cooling system.

After such a workout of your radiator's air purging system, it might now be defeated by some trash under the radiator cap's central venting valve. If this valve is held open by trash in the coolant, the warming engine will just push out water instead of building pressure as it very much NEEDS to. This will cause water consumption when there is really nothing at all wrong. This is also the most likely situation that you are in right now. Remove and clean your radiator overflow tank to eliminate the valve sticking trash and keep an eye on that little valve on your radiator cap.

I often find the valve over sprung such that it won't even work properly on a new cap. I then pry the unit off the cap with the twist of the handle of a cresent wrench and then I cut and stretch the spring pulling that valve shut too hard until I can lift it with my lips easily. The entire unit is only held onto the radiator cap proper with four pin pressed divets around the circumfrence of the black rubbered main unit of the radiator cap. Why they don't fall apart all the time is a wonder to me. At any rate it seems you can't buy working parts sometimes so I include the how to on fixing the vent/air purging valve. It is central to an air free cooling system and an air free cooling system can NOT rust, which is why they are so desirable in the first place. That and pressurized coolant won't boil over until it gets really extra hot. Please ONLY check your radiator cap when the engine is cool.

Chris I would get the coolant system pressure tested and it might show up the problem

Check the fan it is not running,

Thermostat is most probably no more good, or u have a serious air bubble in ur coolant system if it leaked or was repaired recently.
90% chance it's ur thermostat.

Found hints on VolkswagenTalk.com suggesting to check inside engine oil cap. If you find foam (some call it ice-cream) Cylinder head gasket is blown. Went checked, and actually found ice-cream on it. Credit to Hillbill, Man you Rock!

I am now doing pressure test, but no wapping has been detected..problem was just in its early stages. on my way to get a metal gasket, and replace. Cheerz!