How do you know what needs doing each year at a service?

[Harry Bloomfield]

I have never had an engine failure, except when I had a catastrophic oil leak in motion. I have always followed the "12 months or 12000 miles" guide. My oil comes out clear, though I have had used cars where it was obviously neglected and black and I used flushing oil.

Black is normal for a diesel, it will be black within just a few miles, after a change.

 

[Avocet]

My bro who was an Inchcape service manager handling RR and Jaguar/Landrover for many years says much of what the manufacturers and dealers recommend is pure money making and often unnecessary except for raking in the shekels. One of the classics is the five year timing belt replacement "recommended" by Skoda on the basis that you just might be doing 20k miles per annum. Exactly the same belts are used on some Fords where 100,000 miles is the change interval.

I've had precisely the OPPOSITE happen! Wife had an Alfa 156, years ago. Specified timing belt replacement at 60,000 miles. Speaking later to a Fiat UK insider, I found that they did this to try and lure the fleet buyers into buying the cars, knowing that they usually punted them on, before they got to 60k, so not having to pay for a cam belt for each of them was a big lure.

Belt stripped its teeth at 57,000 miles. I got two fingers off Alfa UK because it was out of warranty and hadn't been dealer-serviced. Loads of 156s did this and a year or so later, Alfa changed the replacement interval to 36,000 miles...

 

[Avocet]

You're right. They get written off now instead

The average age of a car at scrapage is going up, though... Currently around 15 years.

 

[Avocet]

Just happened across these two short videos where oil is submitted at 5k,7.5k and 10k intervals to compare results.

- 6mins 40

- 4 mins 30

One comment from the lab that may be of interest to people, is that they say time has no effect on the oil, only usage.

That surprises me. Oils have antioxidants and detergents in them, which, conventional wisdom suggests, get exhausted over time, irrespective of use?

 

[JohnD]

conventional wisdom

People making money out of selling oil?

 

[carmanmemoranda]

That surprises me. Oils have antioxidants and detergents in them, which, conventional wisdom suggests, get exhausted over time, irrespective of use?

Surprises me too for same reasons

 

[carmanmemoranda]

That surprises me. Oils have antioxidants and detergents in them, which, conventional wisdom suggests, get exhausted over time, irrespective of use?

Extra thought on this.

Oils also trap moisture, and the less the engine is used the more water is going to be in the system, so low mileage will be affected in different ways to high mileage.

Its at start up and cold running where most damage occurs, so a high mileage regularly used car (well serviced) needs changing by mileage (mostly) and lower used cars by time (mostly) makes a lot of sense to me.

 

[mointainwalker]

Extra thought on this.

Oils also trap moisture, and the less the engine is used the more water is going to be in the system, so low mileage will be affected in different ways to high mileage.

Its at start up and cold running where most damage occurs, so a high mileage regularly used car (well serviced) needs changing by mileage (mostly) and lower used cars by time (mostly) makes a lot of sense to me.

"

Oils also trap moisture,"

Do they ? Do you have any proof ? Personally I would have thought they repelled moisture. I do agree that most moisture absorbtion is likely to occur on cold start-up ( gut-feel, no back-up ). I find it less likely that oil - static in the crank-case - absorbs moisture .

 

[Harry Bloomfield]

Do they ? Do you have any proof ? Personally I would have thought they repelled moisture. I do agree that most moisture absorbtion is likely to occur on cold start-up ( gut-feel, no back-up )

It turns to a sort of mayo. An old tip when buying a used car, was to remove the oil filler cap, and check for mayo under it. The oil cap being one of the colder parts of the engine, where the moisture condensed out.

 

[JohnD]

I know that condensation occurs in the engine when running cold, and running hot boils it out

But if the car is parked, with the engine bolted together and the filler cap on, is water going to get into it?

 

[Harry Bloomfield]

I know that condensation occurs in the engine when running cold, and running hot boils it out

But if the car is parked, with the engine bolted together and the filler cap on, is water going to get into it?

Not unless the cooling system has an internal leak. Worst possible working conditions are for an engine to do regular short journeys, especially diesel engines. I run a diesel, and I try to limit its use to longer runs, to ensure it always gets hot.

 

[carmanmemoranda]

"

Do they ? Do you have any proof ? Personally I would have thought they repelled moisture. I do agree that most moisture absorbtion is likely to occur on cold start-up ( gut-feel, no back-up ). I find it less likely that oil - static in the crank-case - absorbs moisture .

It doesn't absorb moisture as it sits there like a sponge would, but does as the engine runs. As harry said it emulsifies and can show on cooler surfaces.

The point being that lesser used cars will trap more moisture and not boil it off.

Will see if I can dig out some oil info for a much better explanation

 

[DiyNutJob]

I know that condensation occurs in the engine when running cold, and running hot boils it out

But if the car is parked, with the engine bolted together and the filler cap on, is water going to get into it?

Never had a problem with running cold. Now I do from an oil leak in the engine cover. That also means air leak into the engine.

 

[Burnerman]

For every gallon of petrol burnt, the engine produces the same volume of chemical water.
Some of this water may condense into the oil when the engine is running, but obviously the vast percentage of the water is expelled through the tail pipe. As the engine warms, this water is hopefully boiled off.
Oil doesn’t absorb water when it is in the sump but as it ages it’s additives diminish.
John

 

[Burnerman]

I was weaned on the bright green Duckhams 20/50 in the blue and yellow can....remember that? Castrol GTX was also on the shelves.
I don't know how good an oil it actually was, but it was hugely popular.
Maybe the ultra thin oils we use these days are more adept at dealing with high ethanol fuels.......I haven't a clue about that one!
John