My coolant expansion bottle keeps emptying after about 6/7 miles, I suspected a leaky bottle cos I'd had that problem before but I changed it and it's still happening.

Now I'm looking at the oil and it's not good, can someone confirm head gasket failure? Or another explanation for what's happening?

Cheers

Duane

3.0T engine, 130k

I should also explain the coolant remains clear, no evidence of oil. And the temp gauge never moves...

It might be a blown head gasket, it might be a cracked head, but the most likely cause is a defective EGR cooler.

2 hours ago, Duane1611 said:

3.0T engine, 130k

I should also explain the coolant remains clear, no evidence of oil. And the temp gauge never moves...

Hi most likely the oil cooler the gaskets are flimsy and as the water pressure is higher than the oil pressure it lets water in to the oil system quite cheap for an aftermarket unit but a sod to fit.

Steve.

Thanks Steve, was hoping there might be another reason. Is it something I can do or is it something a professional should do?

11 minutes ago, Duane1611 said:

Thanks Steve, was hoping there might be another reason. Is it something I can do or is it something a professional should do?

Hi not a job I have ever done on an Audi 3.0, done a 2.0 CNHA and that was a real drama, try YouTube and see if its within your pay grade, I thought the 2.0 looked fairly straightforward until I got stuck in and the amount of other stuff you have to remove to get at it was a major faff, loads of bungee cables attached to various panels to keep the pipe work and electrical cables at bay.

Steve.

Mmm, will speak to my audi specialist but I suspect it's beyond me.

3 minutes ago, Duane1611 said:

Mmm, will speak to my audi specialist but I suspect it's beyond me.

Hi just had a look on line and its a Barsteward inlets off and the worlds supply of crud underneath the unit which sits in the middle at the top, easy enough to get to but a multitude of Torx fixings, all different lengths for certain holes so you have to draw a map of what goes where and a murderous amount of new o rings, only reason I think this is the problem is lack of reassure from expansion tank therefore not head related and you water is being fed into the oil system which is not good for any bearing within the engine so it will need a double engine flush after fixing to clear it all out.

Steve.

Yes I did wonder about water in the oil, fairly sure that's not good. I'm used to building engines and stuff, but this is a level of uncertainty I'm not comfortable with, and the potential consequences of getting ot wrong are dire. I've just spent £1000 on a major service etc, so I'm rinsed and mildly miffed.

Hello Duane,

All I would add to what has already been said is - I would strongly advise you not the use the car at all. If you do, you will end up with a wrecked engine in a short number of miles.

Even renewing the oil would be fruitless since in 6 to 7 miles, you would have contaminated that oil with a litre or so of coolant.

Regards,

Gareth.

In worried it might be too late. I've done probably 30 miles of (genuinely) gentle driving, haven't driven it since I realised what was happening. I'm really hoping a good flush will be enough, the engine sounded normal last time I drove it.

I'm going to book it in tomorrow and find what the actual damage is, mechanically and financially... I'll update tomorrow 😕

Fingers crossed for reasonable news.

4 hours ago, Duane1611 said:

In worried it might be too late. I've done probably 30 miles of (genuinely) gentle driving, haven't driven it since I realised what was happening. I'm really hoping a good flush will be enough, the engine sounded normal last time I drove it.

I'm going to book it in tomorrow and find what the actual damage is, mechanically and financially... I'll update tomorrow 😕

Hi don't worry it only gets critical when you reach the level of a pint of water per pint of oil then the ends rattle and the valve gear rattles as there is not enough lubrication for the lifters, I am quietly confident it is no where near terminal, seen worse where its cooked the head and big end bearings, did a Vauxhall Astra a while ago, same problem but worse and two gallons of flushing oil and three filters its still doing a nightly commute to London no issues.

Steve.

That's great news Steve, thanks 😊