Coolant loss

[dmhelsby]

We have a 2004 1.6 fsi that has a continual coolant loss. We’ve had a new water pump and the plastic pipe at the back of the engine block was replaced a while ago but now seems to be the problem again. Has anyone else had this type of problem?

Thanks

David

[Magnet]

Hello David,

A couple of questions before moving on to the logic of this issue. 

Did replacing the water pump and plastic pipe solve the water loss? - which I take you had before you replaced both components? 

How long ago was this done?

If it cured it (did it?) which of the two were found to be at fault? 

How much coolant is the car now using? I take it you have re-inspected both components. 

Is there any evidence of excessive smoke from the exhaust when the engine is thoroughly hot, and revved to 2000rpm and held at that for two minutes? 

Perhaps you could let us know about the above, and someone can then possibly advise. 

Kind regards,

Gareth.

p.s. Is the car relatively new to you? 

[dmhelsby]

The water pump was replaced when the timing belt was renewed a couple of years ago, then the plastic pipe thing was done some time later. It's my local garage that identified where the leak was coming from and have said that it's from that plastic pipe again. It loses about a cupful every couple of weeks which is annoying. Theres no comeback as the repair was done a couple of years ago and the garage doesn't exist anymore. Someone suggested putting some radleak repair in the system but were not keen on doing this.

Not noticed any excessive smoke from the exhaust either.

Thanks

[Magnet]

Hello David,

Many thanks for the additional helpful information, which now shows there isn't any mystery - the leak is external, and from the previously-changed plastic pipe. 

One question now remains:- (which might be unanswerable) Was a genuine VAG replacement part used last time? 

I would certainly agree with your reluctance to put any bodge leak repair in this, and would go with changing the pipe again using a main dealer part. It might be worth asking the Parts Dept. if there has been any history of early failures on their replacement part. Always worth an ask. 

Kind regards, 

Gareth.

p.s. Forget about the exhaust smoke - this would only apply if you could not find any evidence of an external leak. 

[Hampshire_Nick]

Hi Magnet,

Thank you for your full explanation of this issue as you see it.  I have exactly the same problem on my A2 which I have lived with since I bought it new in 2004 (I know !).  It;'s a 1-6FSi with around 70k on it now.  I have NEVER found the source but fill it whenever the bonnet it off or when the warning appears.

My son now has the car for a while, and uses it more often than it used to be, but unfortunately is not as diligent as me and the water seems to be leaking far mnore often.  I have replaced the overflow tank as there was evidence of weeping from the seam, but there are no other witness stains of anything leaking from any other covers or pipes.  I have never found the plastic pipe behind the engine so I will take a look for that one as it is mentioned quite often in forums.  I understand that as the engine coolant usually runs around 110°C so any water escaping will emerge as steam and there will never be a trail of red liquid to trace.  This is also backed up by teh fact that the car never looses water overnight.  Fill it in teh evening, and it will all be there the next day, but drive it once and half the water has gone from teh expansion tank!