1.6 FSI - New Car to Me - Coolant Leak - Advice wanted

SID

SID

Member
Hello,
Last week I purchased a 2004 1.6FSI (privately). By the time I got home the coolant level indicator was showing. The next day I topped it up with 1 litre of water.

I went out in the car for the first time yesterday and did maybe 40 miles. Just as I was getting home the coolant warning came on.

I've not topped it up again as did not wish to dilute the coolant any more.

The temp gauge was at 90 all the time, so do not believe I have over-heated it.

Having a good look under the 'bonnet, I am struggling, but there does seem to be traces of coolant around the 'header' tank, and possible evidence of it pressurising and being released. There looks to be trace of 'splashing' on the flexi tube under the windscreen - seen on one of the photos.

The 'y' pipe looks to be okay, and nothing seemed to be weeping whilst I ran it idling for 5-10 minutes.

No drips below the car.

Maybe I need to get it properly hot?

Hopefully I've not bought a load of trouble. Car drives superb, and feels great.

Looking through the history, the thermostat housing was replaced in May 2015 at 62k. Cam Belt in 2012 at 50k. It now has 65,800 miles on it.

Someone has also previously damaged the breather pipe where it connects at the filler cap, so this will need replacing, which I assume will be straight forward.

And I need to source a wire clip for the back of the headlamp bulb holder as this is absent on one side.

I look forward to any advice.

Many thanks

Simon

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Do you have AA membership or similar? I had a coolant loss and couldn't see where it was coming from at all. Called the AA out and they have a handpump that attaches to the expansion tank and they can pressurise the system. Makes finding the leak extremely easy.

I've had 3 coolant leaks on my FSI. Of the three, the most risky leak was from the big plastic pipe that runs from the waterpump behind the engine. Mine had only just started to leak, but if it goes pop, it can empty the coolant very quickly.

I would try a pressure check on the cooling system if you are able to, as it is the best way to find them.

The fsi works it's cooling system quite hard, and the age of the cars coupled with the use of lots of plastic coolant pipes means that they can spring leaks quite easily. Two of mine were caused after services when the pipes got disturbed then cracked.


Also, it's much better to run an engine with water in it, than nothing. I wouldn't hesitate to fill it up with water if it needed it, we are not cold enough yet for freezing to occur, and you should get it looked at as soon as you can. Ideally avoid driving it, as you have said it is getting through quite a lot of coolant.
 
Oddly Simon, I've just purchased an a2 with a coolant leak and i'm going through the motions to find and rectify it now, I've cancelled out all but the water pump coolant pipe which i'm on the process of getting to now. I'm whippIn the inlet manifold off now to get good access to the engine (I hope!) and let you know what I find!

Nick
 
Hi Nick,

I noticed your thread. Good luck with it. Looks compact and fiddly in there. Is access better from underneath?

Simon
 
The pressure check sounds a good idea. Perhaps this is something I should source - I guess just need a pump and cap that will fir the A2 expansion tank.

Sorry if my post inferred running without topping up. I won't be.

Just did not want to keep blindly topping up and running. Want to find the leak first.

If I can't find myself then will be booking it in for a full service and check over (service not yet due).

But would rather find it myself first then drive for a month or two and then book in to have it serviced and get anything done that needs doing.

I'm new to the A2. It's nice.
 
My leaks were in the following places on my fsi:

Y pipe - top right of engine, noticeable leak as was squirting out

Heater matrix feed pipe - back right to engine, only found when pressure checked by AA

Water pump main pipe - back of engine (possible to see if car on ramps looking up to where downpipe is, access very limited). Found when mainfold flaps and injectors were being sorted.


The last one I think had been leaking a small amount a couple of months, where the plastic pipe had broken apart on one end near the rubber gromit. It was spotted when the intake manifold was off, and replaced as matter of course, but would have been worth replacing for peace of mind anyway.

The pressure check tools are pretty simple, but rely on you having the correct attachment to seal properly onto the expansion tank and are manufacturer specific. This is what the guy used on mine http://www.eurocarparts.com/ecp/p/t...ols1/cooling-system-tools/?538770351&0&t5_394 I would imagine someone handy with tools could fabricate something that does a similar job.
 
I'm on the floor so access is pretty rubbish, finished for the evening now (quick couple hours) but so far it's a pig to work on!!!

Nick
 
In for a full service yesterday.

Unfortunately it is the big plastic pipe that runs from the water pump behind the engine.

This is booked in for next week.

Bit of a painful start to A2 ownership.
 
SID said:
In for a full service yesterday.

Unfortunately it is the big plastic pipe that runs from the water pump behind the engine.

This is booked in for next week.

Bit of a painful start to A2 ownership.
Click to expand...

Your best way to remove the pipe is from the bonnet area, you will need to remove the thermostat housing to get the pipe out anyway so check it whilst its out.
 
shaun5 said:
Your best way to remove the pipe is from the bonnet area, you will need to remove the thermostat housing to get the pipe out anyway so check it whilst its out.
Click to expand...

Be gentle with the thermostat housing, it's quite easy to break if it's the original unit. (I found out the hard way!)

Also be gentle with the coolant y-peices by the header tank, also easy to break.
 
Still losing some coolant.

Is it possible to repair the expansion tank relief valve? (where is it?) or do I need replace the tank?

Looking at the tank, looks like there was (possibly) water coming out of the back (near the top). Not sure where the relief valve is, and struggling to find something on the internet.

Temperature always remains at 90 (when running), but regularly need to top up.

Any advice would be very much appreciated.

Thank you.
 
I would check for hoses as I had about 4 go one after the other once one was changed the next would pop about 2/3 weeks later.

Cheers

Steven
 
I've had a very small coolant leak(s) since I did my water pump pipe and thermostat housing, if your car overheated (but not enough to damage the head) then theres a chance the coolant pipes themselves have swollen, that's the issue with mine at least, no matter how hard I tighten down they're not 100% flush with the associated connector. At some point I'll replace them but there's lots of them and they're probably not cheap! Worth a look either way.
 
Did you replace the cross pipe between the water pump and the thermostat housing? Is so did you replace the thermostat housing as well?
 
After looking at the car when it was hot, a crack in the expansion tank was quite apparent. If you look closely at the initial photos, it is (now I know it's there) just visible.
New expansion tank ordered which will be fitted next week.

Thermostat housing was replaced about 18 months ago.

Hopefully now will be 'cured'.

Many thanks for everyone who has offered advice.
 
Just to add on this I have the same problem I Took her car to work other day and I could see smoke from bonnet so took it off to have a look, couldn't see anything leaking or wet, but expansion tank was low so waited to cool then topped up, drive home and same again, looked under car and see red drips so I know it's coolent but can't see from where, and 2day we stopped at traffic lights and there was smoke every where but still can't see leak any help guys

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Assuming 1.6 fsi?

Same as above really, check all your hoses and thermostat housing but the biggest culprit seems to be the pipe running from the water pump to the thermostat housing (on the 1.6 fsi). If you can raise the car safely you can crawl underneath and give the pipe a good mk1 eyeball, mine was obviously cracked. The pipe is on the back of the engine under the inlet manifold and is a bit of a pain to change.
 
I know there a pain to change but can u get replacement ones from audi or is it a second hand part?

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You can get them from Audi. Not particularly expensive.

Just checked. Coolant pipe & fittings £57.75 charged by my garage that fitted it.

When they changed the expansion tank last week, I suggested they may as well change the Y pieces.

Which they did, and one snapped in half as they removed it, so it was good timing.
 
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