Creamy sludge under oil filler cap.

Faults and Technical chat for the Renault Austral
Coutainville
Posts: 41
Joined: Sat Dec 09, 2023 6:47 pm

Post by Coutainville »

Surely an emulsified cream is not a good lubricant, and definitely not a low viscosity one...

Richmojo
Posts: 14
Joined: Tue Mar 05, 2024 10:03 am

Post by Richmojo »

Hi. I checked under my filler cap today. My Austral is 8 months old and there was a small amount of white emulsion like mayo in mine. It only covered the surface and wasn’t deep. I easily wiped it out, but I will keep an eye on it
Richmojo
Posts: 14
Joined: Tue Mar 05, 2024 10:03 am

Post by Richmojo »

So further to my previous, I spoke to a mate of mine who is very good with mechanics and he says its most certainly condensation especially with the cold wet whether we have had this year and in my case doing very short journeys where my car engine does not get warmed up enough to evaporate any moisture left in the engine block. And in the engine compartment.
janner53
Posts: 2
Joined: Thu May 09, 2024 12:43 pm

Post by janner53 »

Yep, just checked mine and same sludge has accumulated in just 1100 miles, removed with tissue and it has strong petrol smell as others have recorded.
janner53
Posts: 2
Joined: Thu May 09, 2024 12:43 pm

Post by janner53 »

Just checked my wife's hybrid Clio and same sludge with petrol overtones after approx 800 miles. I suspect it's all down to electric power unit not allowing engine to get up to high enough temperature to burn off petrol/water vapour. Long motorway trip coming up so will see if makes a difference.
Mr rugby
Posts: 83
Joined: Fri Nov 10, 2023 9:36 pm

Post by Mr rugby »

You may be right there janner53. With the hybrid engine stopping and starting as it needs too and not continually running like a normal engine, perhaps the temperature variation produces the sludge.
Whatever the reason I don't like an accumulation of sludge/water/condensation, or whatever they wish to call it, floating around in my new engine.

Surely they can implement a better crankcase breathing system to aid this issue.

Can You imagine people who are not mechanically minded or have no interest in checking these things, They will, unwittingly, leave it sitting there under the oil filler cap between services, only to find a generous amount of sludge may have built up over the year.

If we are getting a fair accumulation after 1,000 miles, imagine what could be there after a year or so or 12,000 miles as an example. The model is in it's infancy so we don't yet know do we ?
We did a 50 mile motorway run the other day at full engine temperature, yet the sludge is still there.
In my opinion this is a design characteristic of this power unit.
All we can do is make sure it gets removed regularly.
If this stuff ever shows itself on the oil dipstick aswell, then that's a different ball game.

Mr rugby
blindomatte
Posts: 2
Joined: Tue May 14, 2024 7:00 pm

Post by blindomatte »

Hi there. As I replied on another thread, this issue seems quite common in Full Hybrid engine. At least this is what I recognize being part of a Facebook Austral group.
According to a survey it seems 80% of users have this issue on about 100 users.
I would say this is a problem.

My Full Hybrid is new (about 1000km) and no creamy oil at the moment but I recognize petrol smell in the box and on right side of motor.

We all need to put an eye on this...
BroncoRDQ
Posts: 5
Joined: Sat Jun 01, 2024 4:28 am

Post by BroncoRDQ »

Hi, I believe you will find that it is fuel (Oil Dilution) and not water causing this apparently it is quiet common in Hybrid engines across all cars not just Renault.
Mr rugby
Posts: 83
Joined: Fri Nov 10, 2023 9:36 pm

Post by Mr rugby »

As you know I recently removed some gunk from my oil filler cap and filler neck.
I have since been on 3 motorway blasts , plus some shorter trips and yesterday, when I looked there were no new gunk deposits to see..... as of yet.
I guess I have Probably done about 3 to 4 hundred miles since cleaning.
I shall keep tabs on it, maybe the warmer air temperature is stopping the block from getting so cold and helping to minimise the condensation.

Mr rugby
Mr rugby
Posts: 83
Joined: Fri Nov 10, 2023 9:36 pm

Post by Mr rugby »

As an update,
I have now completed around 3,000 miles and no new sludge deposits have appeared. Quite a few motorway runs have been done and the warmer weather may have helped keep the engine from getting so cold at night.
If it starts happening again as our nights get colder, then we will know for sure it is condensating around the filler cap area due to engine block temperature. Unlike a conventional engine that runs continually and keeps hot, these hybrids switch on and off, heating up, cooling down, heating
up , cooling down.
we'll see.

mr rugby
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