Oil filter change in old car - how often?

Actually since about 2004 Mobil 1 is no longer a true fully synthetic. Mobil lost a test case against Castrol re Magnatec which was claimed to be fully synthetic when it was in fact a hydrocracked Group IV mineral oil. The use of hydrocracking paraffin etc into engine oil makes a boost to profit from utilisation of lower grade stocks. As a result Mobil themselves moved to it, so basically synthetic can mean "true" polyolefin etc or blend of cracked mineral oils.

Reply to
Doctor Drivel
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Don't go by maker name or anything else. Check the spec on the container and make sure it meets/exceeds the requirement for your engine.

Even something like Mobil 1 means not a lot as there have been various versions over the years - and you'll often find 'special offers' which are in fact an obsolete spec. Same with all the other brand names. In Halfords, you'll sometimes find the same brand - like say Magnatec - with the same viscosity but different spec on the same shelf at the same price.

Reply to
Dave Plowman (News)

snip=20

I most definitely agree with that last statement. I bought a used Renault, and the Renault Forum is a great source of help and advice that you don't get from a manual, from folks who have already 'been there and done that'.

--=20 Davey.

Reply to
Davey

Possibly

Wrong. Antifreeze has a lower specific heat capacity than water.

Pressure caps rarely fail. Corrosion inhibitors last for many years. A check every two or three years is enough.

Checked for what? If the mileage / age is within limits and it was fitted right in the first place then they very rarely fail.

Filtered oil doesn't wear pumps. Even totally knackered oil barely wears pumps, pissing about checking the oil pressure is an invasive procedure that rarely proves anything.

It cranks and starts in a couple of seconds. The battery voltage is normal.

End of test

1000 hours at 30mph is 30000 miles, or somewhere around three years average mileage. I can't recall ever changing a lamp for poor brightness. I've had headlamp housings that filled with water and the lamps were still good to use after they had been dried out and cleaned in some meths.

Nice sharp edges give a better spark than ones rounded off by wire brushing or sand blasting. 50,000 miles was possible with very little deterioration in performance 30 years ago, now it's normal. Removing spark plugs every 3000 miles risks thread damage to the head too.

For something tinked with and occasionally driven on a weekend in summer, or after a nuclear strike then it is usable. For all other practical purposes distributors are crap. If they were so good then piston engined aircraft would use them. They don't.

Bigger bang, wtf does that mean? You get significantly higher energy in the spark from modern ignition systems.

Reply to
The Other Mike

Are you sure you are in 2011 and not in some time warp 20 years in the past?

I'd love to know which manufacturers are stil sticking to a distributor rather than coil on plug/double ended coils and a crank / cam trigger.

Reply to
The Other Mike

It wasn't clear that was what you were doing to me, sorry.

There is no conspiracy beyond cheapness.

The Germans and then the Japs started the ball rolling when they installed really good automatic lathes and grinders to polish and shape parts to exact tolerances, and then when they also used top grade materials, their engines started to last, and British ones did not.

End of British mass car industry. People didn't like all that servicing.

Add in EFI and electronic ignition and another source of wear problems and potential engine damage went..engines get better BUT they are always the weak inside and the primary bearings take massive side loads as well.

So whilst a differential these days barring corrosion damage to oil seals, is almost oil sealed for life, the engine still isn't.

Bit of carbon and metal dust will accumulate in the oil: The filter is supposed to take out the worst.. but wear still is happening...

Reply to
The Natural Philosopher

Indeed.

And those who yearn after distributors have a very short memory.

Reply to
Dave Plowman (News)

Too much of a generalization.

Reply to
Dave Plowman (News)

All of them. Without a distributor you need at least one coil per sparkplug, unless you want to take the risk of firing all the plugs all the time and the possibility of a misfire ..

Additionally you need to tell te EFI and ignition system which part of e

4 stroke cycle you are ion to time the sparks and injectors correctly. This means a divide-by-tow rotor and a sensor of some sort..since camshaft is already needed to control the valves, is normal to tack the distributor onto that and use it to do the two things it still needs to do

- distribute the spark to the right plug and

- provide timing information for the injectors and the ignition.

So a modern distributor does less, - its doesn't have a mechanical spark generator in it and it doesn't have centrifugal advance/retard and vacuum advance on it - that's all done electronically, but it still shuffles the spark around and provides a convenient place to put a camshaft sensor.

Look in most petrol cars today, with an OHC and you will see a 5 wire lump 4 a 4cyl engine) stuck on the end of the camshaft, and probably a sixth small wire there as well that's the sensor. four wires go top the lugs, and the fifth goes to a coil or coil pack, which is usually bolted somewhere else

even if the car has one coil per plug, it STILL needs a way to selct those..and the camshaft sensor is still needed.

That's as little of the distributor as you can get away with. Arguably at some point its not a distributor any more - but that is when it stops distributing the sparks and that means an expensive multi-coil ingnition system that is not found much on cheaper cars.

Reply to
The Natural Philosopher

I was there.

VW 10k service interval

BL 3k service interval

Toyota 9K service interval.

Which one isn't there any more?

Reply to
The Natural Philosopher

Never heard of wasted spark? One coil for a pair of cylinders and only the crank position needed.

Err, going back to the days of injection and dizzies, injection was indirect, and injectors fired as a batch. Not sequential. And just when they opened not particularly critical - just the time they were open for.

Why would you go to the effort of providing an accurate map via electronics but use a trigger which is all over the place - jitter from a cam drive and belts or chains which stretch?

Really? I keep on asking - what make is this? What you're describing was on a Maestro...

Wasted spark. Again. But given how common variable valve timing is, a cam position sensor is common too. So that gives the cylinder which is firing.

Are they still making Lada?

Reply to
Dave Plowman (News)

No BL car I know of had a 3000 mile service interval. Can you state which one?

But neither the Japs or Germans 'started the ball rolling' with accuracy in engine making. Possibly at the cheaper end. But that's not what you said.

Reply to
Dave Plowman (News)

All of my midgets had 3000 mile oil changes,

Reply to
The Natural Philosopher

Most things about car engines are designed for a certain acceptable % of failures, given that 0 is pretty much unachievable (even with costly aircraft engines, which is why you tend to have at least two of them!) For instance, a lot of people change cambelts early because that will reduce the percentage chance of an early failure.

I'm not sure to what extent that applies to oil changes, though. I've always done them pretty much according to manufacturer's recommendations (though sometimes a month or so late) and it has never caused me issues. I suppose it *could* reduce the car's life by a few months or a few thousand miles if you do it a bit late, but I don't tend to keep cars that long anyway.

But if you don't change the oil at all, over time it will lose its lubricating properties and gain water and other impurities and so friction and corrosion within the engine will increase.

Neil

Reply to
Neil Williams

Its the key thing really..what does the car die of? usually the body corrosion in a normal sort of usage pattern. No point in making he engine good for half a million miles if the body has long gone

BUT I am fairly sure that commercial diesel engines in big trucks are up for quarter of a million miles, at least.

lower RPM and more conservative ratings and better servicing....

Reply to
The Natural Philosopher

Some engines do seem fussy. Hydraulic lifters seem to have their "acoustic preference".

Oil pickup screen clogging has not gone away. Recent diesel suffer high coke loading on the oil, that coke will accumulate on the screen over time and if it does the end result is usually first turbo failure (oil in intercooler) and then second main bearing failure. There is little warning and buying used with such costly parts needs due diligence (ie, lease where possible).

I think OEM is safest, unless known otherwise.

Sadly they rarely are; they tend to bond panels that should not be bonded; skimp on spot weld count; aftermarket panels are routinely used with dubious corrosion protection; critical drain holes may be neglected or oversprayed with underseal; seals are re-used.

For a front nearside, if that includes anything behind wheel arch trays examine carefully. If a car lacks them the outer wing skin rots off in no time, if the car has them the inner upper "apron" tends to vanish (it is non structural and just carries wiring harnesses, hoses, but can track rust into the frame), if the car has them and they do not seal properly the first you know is when a hole appears in the engine compartment. Water can get behind the the trays, but not air - so they never dry out.

Personally I think corrosion protection has gone to the dogs, which combined with thinner/thicker steels means the thin steels get used in the less structural areas but where corrosion is more likely. This is a recipe for disaster and why many modern cars may actually be unrepairable (unrestorable!) past a certain point compared to those previous.

Reply to
js.b1

A few Volvo used to have a zero tolerance policy linked to the odometer, if you went as little as 200 miles over you got bitten by a very large bill re interference engine.

On some engines if you bend valves you also damage bearings, if they are not replaced they fail some time later. Relative who believes cars are "self maintaining" did the valves, got a backstreet place to do it to save =A3120 (!) and in the words of alfa romeo UK "if the bearings are not replaced we guarantee the engine will fail within 12,000 miles". They were right. It did. Spectacularly on a motorway.

No wonder they want electric cars... computer controlled accident avoidance... programmers saying "now why did it do that...".

Reply to
js.b1

That tends to be the case. Those who advocate halving the oil change mileage could only benefit if they bought the car new and ran it into the ground. And just how many do? And with good quality oil costing perhaps 12 quid a litre it's a significant extra cost.

Oh, indeed. I take the view the makers know best, so stick to their service recommendations.

Reply to
Dave Plowman (News)

Most of the cars on the road aren't that new.

Reply to
Alan Braggins

My 20 year old BMW had dispensed with the distributor. Not the first make to do so either.

So I'll try again - name one car made this century with a dizzy?

Reply to
Dave Plowman (News)

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