Here's one for you Engine stripper builders.

[Duncodin]

It's an 88,000 mile M44 engine. Should the piston crown be this clean?

It looks almost new with the writing still nice and readable. I've had enough engines apart in my youth that this just doesn't feel right - or is fuel nowadays really as clean as they say on the adverts.

My car has done around 100 miles this year - it's been worked on most days, move in and out of the garage and take it round the block now and then but no great milage.

But, it's used a whole tank of fuel. That's not right even for short journeys.

MOT on Friday (Passed, no advisories) and emissions are well within their range - tester even commented on how good the emissions were.

I'm wondering if when the engine is switched off the remaining pressure in the fuel rail is leaking down into the cylinder(s) washing that piston crown? Need to sniff test the oil and endoscope the other cylinders.

But what do you guys reckon?

 

[ChrisD]

It's an 88,000 mile M44 engine. Should the piston crown be this clean?

View attachment 369950

It looks almost new with the writing still nice and readable. I've had enough engines apart in my youth that this just doesn't feel right - or is fuel nowadays really as clean as they say on the adverts.

My car has done around 100 miles this year - it's been worked on most days, move in and out of the garage and take it round the block now and then but no great milage.

But, it's used a whole tank of fuel. That's not right even for short journeys.

MOT on Friday (Passed, no advisories) and emissions are well within their range - tester even commented on how good the emissions were.

I'm wondering if when the engine is switched off the remaining pressure in the fuel rail is leaking down into the cylinder(s) washing that piston crown? Need to sniff test the oil and endoscope the other cylinders.

But what do you guys reckon?

As your engine is port fuel injection and not direct injection, I think the likelihood that your suspicion is correct is slim.
With no signs of anything out of order I suspect you may be overthinking this.

 

[Duncodin]

As your engine is port fuel injection and not direct injection, I think the likelihood that your suspicion is correct is slim.
With no signs of anything out of order I suspect you may be overthinking this.

Likely. But 'under thinking' or 'normal thinking' hasn't helped much.

I can't find any leaks or even moist pipes or joins. The car's in an enclosed garage if there was a leak it'd stink in there - where is the fuel going?

 

[ChrisD]

Likely. But 'under thinking' or 'normal thinking' hasn't helped much.

I can't find any leaks or even moist pipes or joins. The car's in an enclosed garage if there was a leak it'd stink in there - where is the fuel going?

Sorry, I missed your main concern - 100 miles for a tank of fuel.
Yes, if you had a leak you’d smell it in your garage. Over a long period the cold start, warm engine, a couple of miles max and then shut down can end up being surprisingly inefficient.
To know more I’d start again with a full tank and track the hours used, not mileage, carefully.

 

[Peter1450]

Have you noticed your neighbour mowing his lawn a lot?

 

[Duncodin]

Sorry, I missed your main concern - 100 miles for a tank of fuel.
. . . cold start, warm engine, a couple of miles max and then shut down can end up being surprisingly inefficient.
. . .

Yes. That is, kinda, the conclusion I came to but it is pretty extreme. If I'd done 5000 miles a year I'd never notice but just 100 ish is pretty extreme. If I was burning the fuel I might expect to see sooty spark plugs. If I was 'ejecting' unburned fuel I'd expect the cat to have packed in by now or at least not be working well.

 

[Duncodin]

Ignoring the fuel consumption (or @Peter1450 stealing it and blaming my neighbour)

What about that super clean piston crown after 88,800 miles. I could eat my dinner off that.