Coolant level dropping...

[Maelstrom]

Hi Hive Mind.

We've got a 2018 Beach currently on almost 70m miles. It's always driven well and mostly behaved, always serviced and still got the extended warranty.

Had a big service in January, but the coolant warning light came on 21st May (69,132 miles). Got to admit, the coolant's never been an issue. Never had a warning light and never had to top up. I asked at the dealer when I went to pick up a bottle of coolant if it was normally checked with a service and they said no. The level was about an inch below the minimum so I topped it up with half a litre and presumed that was that, as I wouldn't know when it was last filled. Light came on again 20th June, topped up again, crossed my fingers. Just had a look today (69,687 miles) and I don't have a light yet, but it's about an inch below the minimum again.

Should I book it in, or buy another litre? I'm not seeing any other symptoms. Maybe the cooling fan is more obvious at the end of shorter journeys than it used to be.

It's done about 50k in the last 4 years. Long and regular short journeys. This seems to have coincided with me not using it for the shorter journeys as we've just got a new car.

 

[Jon A]

Same symptom for me when my EGR cooler was failing. There are several ways they can fail - one way is the thin metal barriers inside the cooler matrix breaks down and your coolant ends up mixed with the exhaust gas and then enters the cylinder where it gets burnt and ejected.

Might be something else , but you're at about the right mileage for EGR failure , which I regard as a consumable. Mine is a 2019 and EGR failed at 45k

 

[Maelstrom]

I did have the split EGR pipe a year ago. I'll book it in

 

[Resfeber]

Same symptom for me when my EGR cooler was failing. There are several ways they can fail - one way is the thin metal barriers inside the cooler matrix breaks down and your coolant ends up mixed with the exhaust gas and then enters the cylinder where it gets burnt and ejected.

Might be something else , but you're at about the right mileage for EGR failure , which I regard as a consumable. Mine is a 2019 and EGR failed at 45k

And for me at 62,000 (previous T6 Ocean 150bhp dsg. Never had to top up and then coolant light with an empty reservoir.
Had to keep topping up for a month until I could get to dealers for all in warranty repair.
Consumed about 100ml per 100 miles until repair with new EGR cooler

 

[jimmywease]

And for me at 62,000 (previous T6 Ocean 150bhp dsg. Never had to top up and then coolant light with an empty reservoir.
Had to keep topping up for a month until I could get to dealers for all in warranty repair.
Consumed about 100ml per 100 miles until repair with new EGR cooler

Exactly the same for me around 85,000 miles. 2017 T6 150 DSG Beach. Just had EGR replaced for £1200 at indie.

Fingers crossed it was the correct and only cause of the coolant loss…

 

[Resfeber]

Exactly the same for me around 85,000 miles. 2017 T6 150 DSG Beach. Just had EGR replaced for £1200 at indie.

Fingers crossed it was the correct and only cause of the coolant loss…

Don’t be surprised if the level in the reservoir varies for the first week or so.
Don’t think many dealers use vacuum filling so often quite a bit of air is trapped and needs to find its way to the reservoir.
I had 2 or 3 decent top ups before it settled after the egr cooler replacement at main dealer and was a bit concerned as to whether the egr cooler was the only source of water consumption until things settled.

 

[chockswahay]

My son has the same issue on his T6 Combi............. the dealer could NOT find the fault after 4 weeks!

It is still an ongoing issue

 

[Maelstrom]

Well, I've had the EGR valve replaced (I think). I've got a nice shiny new pipe under the bonnet, but no paperwork as it went through on the warranty. Originally told it was the EGR, but when pushed, the EGR valve. Is the EGR cooler visible under the bonnet? I can't tell what else has been replaced but it's booked in again next week...

Was in again after a couple of weeks for something unrelated, and they did a compression test and said it was OK.

Still loosing roughly the same amount. About 15ml down in the reservoir after 150 miles, and now another 5ml after about 70 miles

 

[Resfeber]

The attached image shows the egr valve (ringed in blue) and the egr cooler which
is silver to the left of the valve.
Also this thread on T6 forum

Coolant Leak [Resolved]

Looking for a bit of advice as have mystery coolant leak. 66Plate T6 SWB Shuttle 150 manual At approx 48700miles low coolant alarm went, topped up and drove home as no obvious leak. Was due timing belt (on basis of age) and water pump anyway so got this done at 48879. Garage couldn’t find a...

www.t6forum.com

The shinny new pipe you can see will be the front return pipe for cooled exhaust gases to the inlet.
I cannot remember how these are orientated on the right hand side of the engine block (looking from front in to the engine bay)
Need to query with the garage whether they replaced just the egr valve or both valve and cooler as one unit.
Next possible cause is the charge cooler for the turbo.
What investigation did they undertake?
Pressure tests are the norm and each component tested to exclude (egr cooler, charge cooler and DSG cooler if yours has DSG gearbox and if all these pass then cooling system pressure tests)
Good that it has passed engine compression test.
Hopefully no signs of water in oil (mayonnaise in large quantity at oil filler cap not just the condensate type that appears at the cap/top of oil filler neck nor oil blobs in coolant reservoir.?
If all these are clear but fails a coolant system pressure test then this only leaves failed heater matrix or hoses or water pump.
Hope you get a confirmed diagnosis soon.
My worry would be charge cooler leak and turbo damage.

 

[Aubisque]

Well, I've had the EGR valve replaced (I think). I've got a nice shiny new pipe under the bonnet, but no paperwork as it went through on the warranty. Originally told it was the EGR, but when pushed, the EGR valve. Is the EGR cooler visible under the bonnet? I can't tell what else has been replaced but it's booked in again next week...

Was in again after a couple of weeks for something unrelated, and they did a compression test and said it was OK.

Still loosing roughly the same amount. About 15ml down in the reservoir after 150 miles, and now another 5ml after about 70 miles

I had exactly the same, they pressure tested it also, but as Resfeber says the coolant needed time to settle down after the EGR work (under warranty). When it did, after quite a few miles, no more coolant loss.

 

[Maelstrom]

I had exactly the same, they pressure tested it also, but as Resfeber says the coolant needed time to settle down after the EGR work (under warranty). When it did, after quite a few miles, no more coolant loss.

I've got a couple of hours on the motorway this weekend, so I'll see how it's looking after

 

[sidepod]

Sounds like a bad bleed to me. There should be a bleed valve in the coolant loop to bleed off air locks after a coolant change.

 

[jimmywease]

Don’t be surprised if the level in the reservoir varies for the first week or so.
Don’t think many dealers use vacuum filling so often quite a bit of air is trapped and needs to find its way to the reservoir.
I had 2 or 3 decent top ups before it settled after the egr cooler replacement at main dealer and was a bit concerned as to whether the egr cooler was the only source of water consumption until things settled.

Yeah - still topping up a little bit here and there. If I get through the rest of the
5 litre bottle by the end of the year, then I’ll worry again…

 

[Aubisque]

Any update on this one ?

 

[jimmywease]

Any update on this one ?

All seems fine for me now. Fingers crossed.

 

[Resfeber]

All seems fine for me now. Fingers crossed.

Found an old thread from VW Guru days about this.
Post in thread 'Coolant problems'
https://vwcaliforniaclub.com/threads/coolant-problems.24337/post-298999

He was a VW Master tech and his comments are still valid about EGR cooler failures and time for coolant level to stabilise after this work.

Glad it has stabilised.

Main issue is not to ignore unusual coolant loss and just topping up over a prolonged period.

Water entering the combustion chamber and “washing” cylinder bore will cause significant damage up to a new engine!