Stupid question about car engines

All parts that touch and/or move wear, clearances get bigger, remnants of combustion build up in the engine and bearings, dirt builds up underneath...

You can replace every single wearable part if you want to.

Si

if the oil is correctly changed , you use good fuel and have all the servicing done right then most engines go a little better when they have done some mileage. the principal cause of engines losing power with age is wear leading to lower compression, less valve lift etc.(largely held at bay by good oil change regime), secondary losses will be coke build up.(held off by good fuel.)

A strip and rebuild to new specs will cure almost any worn/dirty bits and restore correct performance.

Correctly looked after a Honda engine will easily exceed a quarter of a million miles with very little loss of power

Mrcheerful

I'd go along with that. The moving parts in a new engine are sliding or rotating on newly machined surfaces. The friction between those moving parts is likely to be greater than it is after the surfaces have 'bedded' into each other.

Modern engines do not need as much 'running in' as they used to, because of improved design, materials, and more accurate machining, but they still benefit from being carefully treated for the first few hundred miles.

IMO how they are treated during that runninng in period can still have a significant affect on their life, and how well they perform during that time. Assuming of course they are also regularly serviced.

the principal cause of engines losing power with age is

I would expect that to be true for most engines, but obviously some are better designed than others. Mike.

Mike G ("Mike G" ) gurgled happily, sounding much like they were saying:

Which, nowadays, means far more frequently than the manufacturer's schedule.

The schedules are set to give low costs for the fleet first buyers, and sod the person who ends up with it 10 years down the line.

Having said that, how many cars die these days because the engines are worn out? Next to none. Ignoring collision damage, most scrappage is because of a pile of small niggling faults - or even maintenance items - costing more than can be logically spent on the car.

Agreed, with the possible exception of some VAG lumps with high oil consumption as standard, and the smaller Zetec ones that shatter their oil control rings if thrashed from cold.

The AA is seeing increasing numbers of cars killed by simply having no oil in them.

Chris

Oddly enough I was just thinking about this the other day: my thoughts were: how long is it since I replaced a set of big end shells or rings? About twenty years !! before that it was not uncommon to freshen up an engine, never happens anymore.

Mrcheerful

Chris Whelan (Chris Whelan ) gurgled happily, sounding much like they were saying:

I did say "worn out" rather than "broken by the idiot behind the wheel"...

Mmm. There's really not a whole lot a manufacturer can do about that kind of fuckwittery, is there?

:-)

Nope; some people just shouldn't be allowed to own a car!

Often, hapless young women whose Fiesta engine has seized solid will openly admit to never having opened the bonnet. They will then become agitated because the patrol "won't" fix the thing!

Chris

Any proof of this? Have you had oil near the end of the service interval analysed to check on its condition? Or is this merely a gut feeling? Because I've heard this said each time service intervals are extended - I can remember when they were only 3000 miles. And engines wore out at

Given my car uses oil at 12 quid a litre I'd expect it to have some advantages. Oh - many makers include servicing during the warranty period, so that makes no difference to fleet running costs.

When a car gets old many simply ignore routine servicing altogether. Hence speeding up the inevitable. But I've yet to see any definite proof changing engine oil early makes an engine last any longer.

I well remember my father's first new car - a Morris Minor 803cc. 1953. It wore out its engine at about the same time as its first set of tyres. And it was serviced on the dot.

That rather disproves your previous point.

Yet people will happily point fingers at Alfa for designing engines which purposely burn oil.

It appears to be a modern engine thing, with the piss-weak oil they take....

"Gruffer" sounds can indicate an exhaust system past its prime.

Now that the engine is worn-in, it's likely the acceleration would be a little better now than when new, and there's no reason the braking should be less sharp (if it's been properly maintained).

I've known many people over the years who insist that their car performs much better after an oil change. Much of what people "feel" about their car's performance is all in the mind.

John

YOu've never driven a Transit then.

True enough!

John

Duncan Wood ("Duncan Wood" ) gurgled happily, sounding much like they were saying:

">> Having said that"

Why did they do that? Or did you mean it was an unintended side effect?

Many VAG cars can use one of two oil grades depending on the type of service schedule chosen. I wonder if there is a difference in consumption between the types?

I've never needed to use a single drop of top-up oil in any Zetec engined car I've owned over the last 14 years, but I still check at least every fortnight. On the odd occasion when I've had a hire car, I always do the under bonnet checks. I also do it if I borrow a car from anyone. It's so simple I can't understand not doing it.

Chris

Not even for screen wash?

Not a chance! That doesn't stop it going along, does it?

One young person that my AA patrol contact dealt with recently had run a Fiesta out of oil. He offered to run her to a garage to get some oil, on the off-chance that it might have survived. (It hadn't.) She was indignant, as she had just paid for an MOT the previous month, so thought it was the garage's fault! She honestly and genuinely believed that all she needed to do to maintain her car was have it MOTed each year. She thought that was what "servicing" was!

I blame whoever taught her to drive...

You would really be amazed at the actions and inactions of the general motoring masses.

Chris