Amazing isn't it that Ford, a mega multi-national corporation, after all this time and experience with engines, can still get it wrong.

I'm sure Ford have experience equal to any other established manufacturer when designing basic engines to end-20th-century standards. The difficulties start when they are forced by legislation and market pressure to make engines ecologically a little cleaner that they have to experiment with new work-arounds, and eager buyers have to do the beta-testing for them. Classic examples of over-elaboration, which even happened in the later days of steam engines.

Here's a good video showing the timing belt replacement on a 1.0 Focus, pretty involved.

www.youtube.com/watch?v=1rG-P1evthg&t=1s

Well, this is exactly the failure mode reported for these engines, hence "traditional"

The "something" that caused the oil pump drive to strip its teeth might, therefore, plausibly have been this commonly reported failure mode, and the appearance of the engine was entirely and specifically consistent with that.

He didn't know the engine history, (though he said it was quite new) , I don't know the engine history...but then you don't know the engine history either, so your assumptions seem at least as questionable as mine are.

I assume its junk, because it became junk, and most engines, until recently, did not spontaneously become junk even if neglected.

Of course this is only one engine, so they wont all fail like that, so its a visual illustration of the commonly reported failure mode rather than evidence for its statistical significance

You seem to be saying it was basically sound because bits of it weren't broken, and the timing belt was only almost broken

There was no visible varnish, most of the mechanical bits looked ok apart from those suffering from oil starvation, and without being able to smell it, the sludginess of the oil was entirely consistent with it having mushed up bearings and belts in it, so where's your evidence of neglect?

Even IF this car hadn't had its uber-special oil change and its ultra-expensive belt change on time, and even IF this explains its sad state, (which is unsupported speculation) I'd say that still implies its too fragile for this real world,

I'm comparing its appearance with my ancient engine which hadn't had a cambelt change in 13 years, an oil change in 6 years and had a history of putting a lot of metal in its oil.

You could compare it with, IIRC, your Ford Focus, which, again IIRC, had a bit of a stretch on cam belt and OCI, yet did not spontaneously autodestruct

And then there's the keyless crankshaft pulley...

Edited by edlithgow on 01/10/2023 at 12:49

As well as the traditional oil failure damage, this example has a lot of carbon on rings and piston tops compared to my ancient-running-rich-carburretted-but-actually-eco-cos-it-was-old engine, perhaps because of the direct injection.

That's progress

Seems other manufacturers are now waking up to the long term problems of using direct petrol injection & now copying the Toyota / Lexus D-4S set up.

Using both direct & port petrol injection is the proven way forward. .

I don't know this is down to DI.

That would rather simply explain valve back coking but its less clear why it would coke up pistons.

If I had to pick something, I'd go for skinny oil loaded up with viscosity modifiers, low tension rings, plus maybe EGR, if it does that.

Whatever it is, its not good.

Heres a very long, vey poor quality online article on the topic, which says almost nothing meaningful. This is increasingly typical of internyet material. That's progress too.

vehiclefreak.com/bad-piston-rings-causes-and-fixes/

Not sure if its a product of Artificial Intelligence or Automotive Idiocy, but if the latter it may have been translated from Chinese. I'm pretty sure this is where the Taiwan DMV get their test material from.

Edited by edlithgow on 03/10/2023 at 00:43