General consensus on long interval oil changes.

[Megaflow]

I know we are members at work, but who has the access to the papers is anybodies guess...

[Sheepshanks]

GreigM said:

Just throwing this in for discussion, not arguing it is the case. If you look around the unsanitary corners of the web (other car forums mostly) there is frequent reference to a SAE paper (number 2003-01-3119) which was a study by Ford and Concoco Philips. The study apparently says that too frequent oil changes can cause unnecessary wear to engines.

The theory behind it goes that new oil has a certain amount of additives/detergents to clean the inside of the engine somewhat. These are designed to be used, then break down and leave a nice cleaned engine running well with all the crud being caught by the filter. By changing too frequently you are effectively over-using these additives which isn't good for the engine.

I'd like to read the full paper to be convinced, but can understand the logic.

I've seen US oil analysis threads that show the same thing - wear increases for a few K miles, then levels off, then starts increasing again.

I'm guessing it must be pretty marginal though. If it was significant the Yanks wouldn't get hundreds of K miles out of engines on 3K oil changes as they'd be worn out!

[Willy Nilly]

DKS said:

I decided on 3-4k oil changed because that was when the oil started to turn black. I do fear the day I buy a diesel, of course.
Plus, well, it's quite satisfying isn't it? Also a good chance to have a quick look underneath and behind the wheels whilst you're under it and stuff.

Oil holds the dirt in suspension which is why it turns black. It's not so bad now, but on the older diesels you could change the oil, run it for a day and it would be back.

Someone I know bought a 1998 diesel Astra van at least 6 years ago. It had just turned 100,000 miles and now is about 180,000 and in the time he has had it he has NEVER changed the oil.

[rigga]

Willy Nilly said:

Oil holds the dirt in suspension which is why it turns black. It's not so bad now, but on the older diesels you could change the oil, run it for a day and it would be back.

Changing diesel oil on vauxhalls back in 2002 when I left the trade, you changed it, started the engine to circulate the oil, then checked it only to find it was already black.

[Mave]

St John Smythe said:

Mave said:

St John Smythe said:

Mave said:

St John Smythe said:

Mave said:

Megaflow said:

TheEnd said:

Mave said:

So why do VAG engines, serviced to the manufacturer schedule, with the correct oil maintained at the right level, have a history of failing catastrophically at 100k miles or thereabout?

Is it really that common? This is quite a large motoring site and I've certainly heard of things like N75 valves needing to be replaced, and coil packs going, but I haven't heard about this engine apocalypse you are talking about.

Indeed. I have no idea what this reputation is either.

Google VAG 1.8T oil sludge or oil pickup blockage (or do a pistonheads search on "1.8T oil")...

Don't believe everything that you 'Google'. The internet blows everything out of proportion. If it was such a massive problem as you suggest then it would be all over the media, etc and common knowledge.

Tbe only thing I can remember seeing "all over the media" and in common knowledge is the Toyota stuck pedal incident. Are all the other mechanical failure issues discussed on Pistonheads simply internet exaggeration, and not happening in the real world?

I wrote my comment in response to the assertion "If an engine is serviced correctly and never allowed to run low on oil, putting aside special causes there is no reason why the mechanical of engine shouldn't keep running well beyond the 250k." Whether or not the internet blows things out of proportion, surely the fact that well maintained VAG 1.8T engines HAVE failed at ~100k miles due to oil degradation brings that assertion into question?

Do you know what % of engines have failed?

No idea at all. Enough to be well known amongst VAG specialists. Serious enough problem to write off cars. Do you think that an engine family that has history of degrading to the point of failure at 100k miles should be confidently expected to achieve 250k miles?

So you don't know then. I'd hazard a guess that the vast majority of VWs with this engine are running just fine.

Do you know what percentage of these engines are running fine at 150k miles?

If there are engines which have failed at 100k miles, but apparently they SHOULD be able to reach 250k miles, then that's a HUGE statistical spread on how the oil system behaves for what is essentially a wear out mechanism. Which just means that the system isn't robust. If the system (including specification of maintenance) were robust, then what's the phenomenon that causes some of these engines to fail so much earlier than others?

[skyrover]

3 million miles on this volvo and still going

http://www.classicvolvorestoration.com/3millionmil...

Oil change every 3500 miles apparently

[Megaflow]

skyrover said:

3 million miles on this volvo and still going

http://www.classicvolvorestoration.com/3millionmil...

Oil change every 3500 miles apparently

That is very interesting. Out of curiosity I checked Volvo's recommended oil change interval for the P1800. For normal driving, which is classed as decent runs and motorway driving, something I think we can safely say this car does, it is 3000 miles.

The to Volvo has made it to 3,000,000 miles by having its oil changed 500 miles after the manufacturer recommends!

Remember kids the manfacturers don't know best...


Service manual: http://volvo1800pictures.com/document/Service_manu...

[anonymous-user]

Mave said:

St John Smythe said:

Mave said:

St John Smythe said:

Mave said:

St John Smythe said:

Mave said:

Megaflow said:

TheEnd said:

Mave said:

So why do VAG engines, serviced to the manufacturer schedule, with the correct oil maintained at the right level, have a history of failing catastrophically at 100k miles or thereabout?

Is it really that common? This is quite a large motoring site and I've certainly heard of things like N75 valves needing to be replaced, and coil packs going, but I haven't heard about this engine apocalypse you are talking about.

Indeed. I have no idea what this reputation is either.

Google VAG 1.8T oil sludge or oil pickup blockage (or do a pistonheads search on "1.8T oil")...

Don't believe everything that you 'Google'. The internet blows everything out of proportion. If it was such a massive problem as you suggest then it would be all over the media, etc and common knowledge.

Tbe only thing I can remember seeing "all over the media" and in common knowledge is the Toyota stuck pedal incident. Are all the other mechanical failure issues discussed on Pistonheads simply internet exaggeration, and not happening in the real world?

I wrote my comment in response to the assertion "If an engine is serviced correctly and never allowed to run low on oil, putting aside special causes there is no reason why the mechanical of engine shouldn't keep running well beyond the 250k." Whether or not the internet blows things out of proportion, surely the fact that well maintained VAG 1.8T engines HAVE failed at ~100k miles due to oil degradation brings that assertion into question?

Do you know what % of engines have failed?

No idea at all. Enough to be well known amongst VAG specialists. Serious enough problem to write off cars. Do you think that an engine family that has history of degrading to the point of failure at 100k miles should be confidently expected to achieve 250k miles?

So you don't know then. I'd hazard a guess that the vast majority of VWs with this engine are running just fine.

Do you know what percentage of these engines are running fine at 150k miles?

If there are engines which have failed at 100k miles, but apparently they SHOULD be able to reach 250k miles, then that's a HUGE statistical spread on how the oil system behaves for what is essentially a wear out mechanism. Which just means that the system isn't robust. If the system (including specification of maintenance) were robust, then what's the phenomenon that causes some of these engines to fail so much earlier than others?

You're blowing the whole thing out of proportion. As someone mentioned above, VW made a lot of these engines and despite what you have said they haven't all desintegrated

[Pit Pony]

powerstroke said:

Remember service intavals are set to make a new car look cheap to run and not to maximize life ...

It's worse.

They are designed to ensure that hire car companies never have to service the car whilst they own it. If they loose a couple of engines, and have to replace them under warranty, it comes out of the profit they wouldn't have made if they hadn't sold them.

If I had a turbo car, and it did short distances I'd be particularly fastidious about oil changes.

[Heaveho]

Well it's been a fun, but ultimately pointless thread, nobody's going to change anybody else's mind. I'll stick to my schedule, and everyone else will do the same with theirs. When my car pegs out due to too many oil changes, you'll all be the first to know!

[Mave]

St John Smythe said:

You're blowing the whole thing out of proportion. As someone mentioned above, VW made a lot of these engines and despite what you have said they haven't all desintegrated

i
And you're ignoring the evidence. An engine suffering from sludge and carbon build up is not healthy, and certainly not likely to survive a further 100k miles or so. A service interval that allows that level if deposit to build up is not in the best interests of the engine, or the owner.

[anonymous-user]

Mave said:

St John Smythe said:

You're blowing the whole thing out of proportion. As someone mentioned above, VW made a lot of these engines and despite what you have said they haven't all desintegrated

i
And you're ignoring the evidence. An engine suffering from sludge and carbon build up is not healthy, and certainly not likely to survive a further 100k miles or so. A service interval that allows that level if deposit to build up is not in the best interests of the engine, or the owner.

Evidence? It's only evident that the vast majority of VWs with this engine are running fine. You can argue all you like but it doesn't change the facts

[Mave]

St John Smythe said:

Evidence? It's only evident that the vast majority of VWs with this engine are running fine. You can argue all you like but it doesn't change the facts

So what percentage of engines made is to 250k miles without an oil related problem?

[anonymous-user]

Mave said:

St John Smythe said:

Evidence? It's only evident that the vast majority of VWs with this engine are running fine. You can argue all you like but it doesn't change the facts

So what percentage of engines made is to 250k miles without an oil related problem?

99%. The other 1% exploded due to the internet.

[TheEnd]

Since the US VAG drivers are getting sludge problems at 5000 mile intervals, and since only one of the transverse vs longitudinal engines gets it, it's looking like it's a clear engine design problem, not down to old oil.

If I were to hazard a guess, it looks like the turbo is overheating the oil on some models.

[Mave]

St John Smythe said:

99%. The other 1% exploded due to the internet.

So you don't know then :-)

[Mave]

TheEnd said:

Since the US VAG drivers are getting sludge problems at 5000 mile intervals, and since only one of the transverse vs longitudinal engines gets it, it's looking like it's a clear engine design problem, not down to old oil.

If I were to hazard a guess, it looks like the turbo is overheating the oil on some models.

Yeah but don't worry, the OEM will have done enough testing and development to make sure the engine is good for 250k miles. These sludge problems are just an internet myth...

[TheEnd]

...perpetuated by a small minority, and unknown to the general public.

[Mave]

Is that the same general public that know VWs are reliable, Alfas rust, and you need to be rich to own a BMW?

[anonymous-user]

Mave said:

St John Smythe said:

99%. The other 1% exploded due to the internet.

So you don't know then :-)

Think I'll go with TheEnd's post above. Sounds like a fundamental engine design problem, not lack of oil changes Maeve.