A3 losing water - rough Water, Wa

[watercool]

Hi all,
I've had my 2003 A3 2.0 Tdi for a few months now and it's got some issues.

1) It's losing some water, not too much..about 250ml every week. Oil looks ok and no smoke or white coming from exhaust.

2) the idle isnt consistent, once I start the car the idle is ok for a few seconds then climbs and gets faster for a bit, then drops again.etc

3) the engine management light is on.

Other than the idle and being a bit jerky (throttle response) the car drives really well.

Please could someone help me, what should I check first? I can't afford a new car so need to troubleshoot this myself.

Thanks

 

[ch1z64]

#1 check bottle doesn't have a slight crack in it , plus pipe work for any leaks.
#2 check your Pcv is tight and again all hoses leading to and going away from .
#3 get your car scanned as it could help fix problem by given suggestions via fault codes to what it could be , do this last after doing #2 first .

 

[SootySport]

Yes, the coolant bottles are prone to cracking on all the VAG cars of that era. Also the EGR cooler can leak internally, that part is also expensive sadly.

 

[watercool]

Ok, I've just scanned the car with my cheap scanner and got the code info off Ross-Tech.

Here we go

17055 - Cylinder 1 glow plug circuit - electrical fault
17058 - Cylinder 4 glow plug circuit - electrical fault
19888 - (Don't know what this code means)
18051 - It says on RT 'Please check DTC memory of electric load controller - check central ECM for fault codes'
16502 - Engine Coolant Temp Sensor (G62) Signal too high
16785 - EGR insufficient flow detected

Does that make it clearer on what the water loss could be?

 

[ch1z64]

Please PM admin @Sandra and ask her to put this post in the correct section where more people would be able to help you

 

[watercool]

Can't see any leaks anywhere, but will continue to monitor.
I've ordered a new lid for the expansion tank (solved a similar issue on my golf) and a new temp sensor. Just because they weren't expensive.

My cheapy code reader won't erase the fault codes on the A3 (but will erase on my Golf?!) so now I'm thinking maybe I need to have the codes erased (by who?) and see what codes come up, as the previous owner might have fit new bits n bobs and not had the codes erased.

 

[Rideen]

Being a 2003, you're almost guaranteed your cylinder head has seen better days.

Edit: To clarify, I'd be certain it's porous and leaking water into cylinder.

 

[watercool]

So I cleaned out my EGR valve this weekend, it was fairly gunky but I've seen worse. I also fit a new coolant temp sensor. None of these things have solved my rough idle though. EML light still on and it sounds like the fan comes on straight away now?

It still needs glow plugs and the water leak sorting. I'm monitoring the water now to see where it's coming from, there are two small water patches on the floor under the car so I'm still hopeful it's an external leak.