Foam on oil cap and strong blow-by 204

[samgti16v]

Hi I’ve got a T6 with the 204 BiTDI engine and upon opening the bonnet and looking at the oil cap I found a large amount of white/brownish foam on the cap and neck. I then started the engine and most of it blew out however some still remains.

It is 2 and a half years old and has only done just over 2000 miles. It doesn't get used much and had its first oil change back in September and since then it has been doing long journeys over an hour on the motorway about once a month with a few short ones here and there.

I discovered the foam on the cap today and it has done 250 miles in the last 2 days on motorways and A roads. When I took the cap off there is a large amount of steam and wind coming from the filler neck, it feels very pressurised which I don’t think it should be for a low mileage engine.

I would also like to add when I picked the van up from its service when I got home about 30 mins from dealers I noticed steam coming from the bonnet and found they had forgotten to put the oil cap back on.

Thanks in advance for the advice

 

[Dellmassive]

More info...

Tpi 2043895/3 - Condensed Water Formation On Oil Filler Neck

TPI 2043895/3 - condensed water formation on oil filler neck. Technical product information Transaction No.: 2043895/3 Service info: condensed water formation on oil filler neck Release date: 11-Dec-2017 Customer statement / workshop findings White paste/foam/sludge in oil filler neck. ...

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[Pete C]

What colour is the oil on the dipstick ?

Pete

 

[samgti16v]

What colour is the oil on the dipstick ?

Pete

If I remember correctly it was a very dark black colour however as soon as I removed the dipstick with the engine running steam started coming out and oil was spitting everywhere.

 

[Dellmassive]

Take a fresh dipstick reading with a cold engine and post a pic.

I can't imagine VW over filling the engine.......

But you say they left the filler cap off?....that's not good.

 

[samgti16v]

Take a fresh dipstick reading with a cold engine and post a pic.

I can't imagine VW over filling the engine.......

But you say they left the filler cap off?....that's not good.

Ok will try and do that tomorrow, yes the cap was left sitting on the water gutter area at the top of the engine bay. The only reason I noticed it is because where I live we park the van on a steep hill and you rev it a bit when reversing up and while doing this I saw steam coming out of bonnet.

 

[DaveD]

While you're there check the coolant level and check it for contamination, a sort of oily scum on it. It only takes a few seconds. It's probably fine but worth checking.

 

[Bigsidavies]

Take a fresh dipstick reading with a cold engine and post a pic.

I can't imagine VW over filling the engine.......

But you say they left the filler cap off?....that's not good.

I did that when I checked my oil the other week. The benefit of the long filler neck is that you don’t lose much oil.
And the cap was trapped under the bonnet so was still there, which was a bonus.
I only realised because I could see smoke coming from the bonnet after a couple of miles.
I’d say the foam and smoke isn’t anything to worry about personally.

 

[DXX]

It is 2 and a half years old and has only done just over 2000 miles

That means it has either been sat idle for a long period and / or very short journeys, neither of which is good for any engine unless it’s a lawnmower.
The emulsified scum appears to be ‘normal’ for a 204ps, see earlier ref to VW doc’, from an engineering point of view it’s not great but but no chance of it going away, that’s how it is. The best you can do is wipe it out carefully on a regular basis.
You can select oil temperature on the MFD and on long drives try to keep the oil temperature above 100 deg C to drive of any condensate in the crankcase / oil.
The ‘wind’ that was described is blow by gases and oil vapour which is normally controlled by the PCV system when the filler cap is in place, the CXEB engine runs at approx 2 bar boost at full load from what I recall which is quite high and this will be contributing to the blow by, that said I’m assuming you saw the blow by at idle speed.
At 2000 miles the piston rings should have bedded in and be sealing well.
If you are concerned raise the issue with VW, use email as then you will have a record and it will be logged while you are within warranty.

 

[catfood12]

There's quite a bit of discussion and some very good example pictures in this thread;

So I looked in the engine bay..and then the oil filler

Just arrived home in a courtesy van from the dealership. My 102 is 2 yrs old and has 8500 on the clock, after numerous visits to sort out the an adblue fault and amber engine management light after 2000 miles. I now have mayo gunge on the dipstick. Tried to fob me off with an service oil...

www.t6forum.com

Also the fix I did of some insulation around the filler neck & dipstick tube.

 

[VanDamMan]

If once you’ve checked that all fluid levels are correct….it’s more than likely a seasonal temperature normal occurrence….moisture trapped in the engine that will create at the coldest point …an emulsified oil/ water gel …..just clean it out every time it occurs…..you will never see it in the warmer months…short journeys don’t allow the engine to heat up and burn of the moisture/vapour..
But all said above…

 

[samgti16v]

That means it has either been sat idle for a long period and / or very short journeys, neither of which is good for any engine unless it’s a lawnmower.
The emulsified scum appears to be ‘normal’ for a 204ps, see earlier ref to VW doc’, from an engineering point of view it’s not great but but no chance of it going away, that’s how it is. The best you can do is wipe it out carefully on a regular basis.
You can select oil temperature on the MFD and on long drives try to keep the oil temperature above 100 deg C to drive of any condensate in the crankcase / oil.
The ‘wind’ that was described is blow by gases and oil vapour which is normally controlled by the PCV system when the filler cap is in place, the CXEB engine runs at approx 2 bar boost at full load from what I recall which is quite high and this will be contributing to the blow by, that said I’m assuming you saw the blow by at idle speed.
At 2000 miles the piston rings should have bedded in and be sealing well.
If you are concerned raise the issue with VW, use email as then you will have a record and it will be logged while you are within warranty.

I always have the oil temp up on the mfd as I always like to wait until it hits 90 before pushing it hard. It hasn’t idled much at all and recently it has been doing long motorway journeys over an hour. Near where I live there is a very steep part of the dual carriageway and I put my down going up there and got the oil to 114 degrees which is why I was surprised to see the foam around the cap.

 

[samgti16v]

Take a fresh dipstick reading with a cold engine and post a pic.

I can't imagine VW over filling the engine.......

But you say they left the filler cap off?....that's not good.

Sorry about the delayed reply but I have taken a pic of the dipstick and it looks like there is no foam on there.

 

[Tony Abbott]

Hi I’ve got a T6 with the 204 BiTDI engine and upon opening the bonnet and looking at the oil cap I found a large amount of white/brownish foam on the cap and neck. I then started the engine and most of it blew out however some still remains.

It is 2 and a half years old and has only done just over 2000 miles. It doesn't get used much and had its first oil change back in September and since then it has been doing long journeys over an hour on the motorway about once a month with a few short ones here and there.

I discovered the foam on the cap today and it has done 250 miles in the last 2 days on motorways and A roads. When I took the cap off there is a large amount of steam and wind coming from the filler neck, it feels very pressurised which I don’t think it should be for a low mileage engine.

I would also like to add when I picked the van up from its service when I got home about 30 mins from dealers I noticed steam coming from the bonnet and found they had forgotten to put the oil cap back on.

Thanks in advance for the advice

View attachment 142047

Hi. Did you find out why you had scum in the filler neck, I too have this

 

[Loz]

Hi. Did you find out why you had scum in the filler neck, I too have this

Totally normal for these engines.
see: So I looked in the engine bay..and then the oil filler