Coolant leak - what is part this called and is it realistic for me to attempt to fix?

[ianlovatt]

I will go trawling through the forum to try to find the answers myself as best I can but thought I'd also post first in case these are easy ones for someone.

53 plate 1.9tdi ~240k miles.

Finally got her up on some ramps and all the plastic engine guards/covers off and noticed this dripping at the back of the engine next to battery/plenum chamber area:
Shared album - ian lovatt - Google Photos


1) What is this part called?
2) Is it worth getting a genuine audi replacement or are other pattern parts ok here (garage I normally use won't use genuine parts)?

Looks like PITA to get access to and I'm feeling a bit intimidated at the thought what bits I might have to pull off to get to it. I've changed the thermostat, rear wheel speed sensor and electric window cradle assembly thing on this car in the past. I have some ramps and a stubborn attitude plus willing to invest in some tools if needed. So based on that resumé of my experience:

3) Is it something a I can tackle (I realise this is a subjective question)?
4) Assuming it's a garage job is there anything else worth getting done whilst they've gone to the effort to get access to this area?
5) Does a leak in this place generally remain as a slow leak for many hours of use or does it tend to result in a sudden catastrophic failure when miles from home with all the family in the car?

I read the fault codes out with VCDS before poking around and nothing related to this came up (so many problems seem to result in that being asked I thought I'd do that just in case). Car's never had a coolant leak. Coolant level warning came on for first time back in May. Filled it up with about 1.5l of water. Since then noticed after every 2hours driving the level is noticeably lower and re-filled accordingly.

We took it down to the south of france at new year in an overnight 1000km 13hr 130kph thrash on the autoroute and I wondering if this sort of sustained effort might have been what caused it?

Any advice appreciated
Thanks,
Ian

[Crasher]

Looks like the head outlet flange, the part varies by application.

[ianlovatt]

Thanks for the quick reply.

It's an AVF engine so having looked up "head outlet flange" it seems like the right part might be 038 121 144 A
eg Coolant Flange 038121144A OE Number buy online

Cheers
Ian

[ianlovatt]

A bit of google image search has lead me to
Unplugging electrical connector at coolant temperature display senderG2 - vehicles with 1.9 ltr. TDI engine

Assuming I'm on the right track this makes it seem fairly straightforward...
EDIT: I'm not on the right track - missed the fact that this is only for disconnecting some nearby sensor not removing the flange! Hmm

Also searching on the forum here for "head outlet flange" didn't result in anything relevant as far as I can tell so either I'm missing something obvious or this isn't a regular issue for people. Normally I've found someone has already bumped into any problem I encounter...

Ian

[ianlovatt]

Any further thoughts from anyone on the questions (1-5) above would be much appreciated.


Erring on the side of going to the garage currently as I'm not sure exactly what parts I need to get and what's involved if there's a gasket to replace.

Cheers
Ian

[VAG-Abound]

The parts diagram shows an o-ring in there, and says M6 bolts to hold it. Looking at your picture it either uses threaded studs, or someone put that in after losing a bolt. If the latter and its worked loose then a new bolt may be all that is needed.

I'd also look if a can of radweld would be a bad thing. Popped one in our car a dacade ago to try and fix a slow leak and it did, with no noticeable ill effects.

[ianlovatt]

Thanks so there's no gasket to worry about just an o ring? Have I got the part number right then for our car (details above)?

I don't think this has ever been tinkered with before (known the car from new) so I think the stud and bolts are original.

Yes good old radweld, kept our renault19 going for years that but I'll try not to resort to that unless it's going to be big money to fix this.

Cheers
Ian

[arman123]

part number for part is 038121144A buy from Genuine 038121144A Coolant Flange, end of head | AVS Car Parts

part number for oring is 037121687 buy from Water Flange Seal 037121687

and if you wana change the bolts part number is N90280904 buy from FILTER PARTS

[ianlovatt]

Thanks for confirming the part number and the o ring etc much appreciated.

Took it to the garage today and they had a quick peek and thought the access was ok and ordered the part. Hopefully they'll sort it next Wednesday.

I will check that they get a new o ring too.

[MrPresident]

I not long ago replaced this on my car as it had cracked, fairly straight forward job. Part is cheap. I did the hose too which was probably unecessary.