Should new engine oil get dirty quickly

[daverclasper]

Hi.

 

When I change my oil about every 3000 miles it seems quite clean (a teaspoonful is brown, rather than black).

 

Iv'e read that if oil is doing it's job, then it's quite dirty before that mileage.

 

Any thoughts please.

 

Cheers, Dave 

 

[KevinR]

It all depends on the oil, how dirty the internals of the engine are, and how much sludge there is in the sump.

 

If the engine has been well maintained and is internally clean, then the oil should remain fairly clean for a decent mileage.

[GT6M]

Also depends on hoo olde yer engine is

worn rings, lots of blow by at hier revs,/Load

will have the oil black in nee time

 

M

[Steve C]

Hi Dave

 

It can also be about the type of driving you do. Oil works best when stinking hot, which is why cars which live on motorways tend to be able to go on to high mileages before they need a rebuild, while the same model that has only ever done short sharp trips can need one at 70k. The best favour you can do your classic is to take it on a motorway once in a while.

 

Like you I am a disciple of regular oil changes, more often than specified. Oil is cheaper than engines, and manufacturers have a vested interest in being able to cite low running costs. Tribology has improved tremendously with modern synthetic oils, and they don't break down in the way the mineral oils our cars were designed for do. I have always been a GTX (latterly Halfords Classic) user, and have never been tempted to put modern oils in, although I know some members swear by them.

 

I also think how an engine is run in can affect its lifespan. All my rebuilt engines have had 50/250/500/1000/3000 mile oil and filter changes. Some would call that excessive, but they have all run to very high mileages, and I have always been surprised at the crud that comes out on the first couple ofl changes!

 

Regards

 

Steve C

[dougbgt6]

When I was an apprentice my boss's boss had a mk1 Cortina, it had done 120k miles and never had an oil change, just top ups. He believed engine oil changes were a manufacturers con trick. He sold the car to someone in the factory who immediately did a major service on it. Needless to say the engine died shortly after. Big boss was unrepentant and claimed "He shouldn't have changed the oil!"

[Pete Lewis]

we had a a  bypass filter/centrifuge  on some hire trucks to extend oil changes to 100k,  this relied on the main filter being changed at the normal service interval   obviously this didnt happen the engines died , on examining the main filter it was full like concrete

also found they were getting oil from BQ, not the high grade all singing proper stuff .... and i had this button marked claim rejected

....that raised my poularity a lot .

 

so if you filter it to remove the contaminants the base oil is still perfectly OK  you wont find a filter because

over the years there has been many supa dupa filters developed and then bought up and removed from circulation to protect

the after sales market of oil .......    good aint it 

 

  just some waffle     Pete

[SpitFire6]

Hi,. 

 I don't think you will ever find a magic micron filter as it will block up too quick?

 

I have a bypass oil filter on my car. My oil is filtered better than any oil filter.

Not running 20W50 mineral helps as well I think.

 

Cheers,

Iain.

[David McHugh]

Hi Dave

 

It can also be about the type of driving you do. Oil works best when stinking hot, which is why cars which live on motorways tend to be able to go on to high mileages before they need a rebuild, while the same model that has only ever done short sharp trips can need one at 70k. The best favour you can do your classic is to take it on a motorway once in a while.

 

Like you I am a disciple of regular oil changes, more often than specified. Oil is cheaper than engines, and manufacturers have a vested interest in being able to cite low running costs. Tribology has improved tremendously with modern synthetic oils, and they don't break down in the way the mineral oils our cars were designed for do. I have always been a GTX (latterly Halfords Classic) user, and have never been tempted to put modern oils in, although I know some members swear by them.

 

I also think how an engine is run in can affect its lifespan. All my rebuilt engines have had 50/250/500/1000/3000 mile oil and filter changes. Some would call that excessive, but they have all run to very high mileages, and I have always been surprised at the crud that comes out on the first couple ofl changes!

 

Regards

 

Steve C

[David McHugh]

Hi Steve C,

 

I am in the process of yet another block rebuild and wondered what you thought of my idea, when complete use a diesel engine oil to run the engine (car stationery) for say ten to 20 minutes at about 2000 reves, drain itand replace with Halford classic and follow your regime of 50/250/500/1000/2000.The reason I thought of using the diesel oil first, is to try to remove the sludge that gets stuck on the internal surfaces. I have removed what I can but feel that a wash out with diesel oil will get to the places I was unable to reach.

 

I would value your and anyone else's thoughts / comments on this.

Thank you in advance,

Kind regards

David late 1973 Spitfire IV original 1300cc

[Pete Lewis]

if you work out how its lasted all these years with heaven knows what servicing I have a thought its best to not get too emotive 

at this stage of the cars life,  we dont tend to do 20k a year and even if you drive like you stole it ,  if you analyse the miles per anum with the cost of oil you may not realise  the  real  cost per mile ....for what!!  over and above the normal spec and schedule.

 

there have been a good few posts about cleansing and old crud removal and the easiest is if its settled and clinging on to leave it alone ,  dislodging can cause more than it cures 

 

is that  down to preference syndrome we all suffer 

 

Pete

[dougbgt6]

"the easiest is if its settled and clinging on, leave it alone"

 

That's what Mum used to say about Dad!  

[Steve C]

Hi David

 

I would just go with a good 20w50 multigrade, and change it often. You don't have to be as fanatical as I am, but more frequently while running in, and then every 3,000 miles (or annually, whichever comes first) thereafter will be fine. As Peter says, these engines are tough old beasts, and took a lot of abuse in period.

 

Older engines like ours have greater running tolerances than modern, all-alloy engines, which are made on CNC machinery by robots to very tight tolerances. Modern synthetic oils have a low viscosity, to get into those tight running clearances easily, and are made from synthetic compounds that do not break down even under extreme conditions, and can survive for long periods between oil-changes, as specified for today's vehicles with 10,00 mile service intervals.

 

Our engines had higher viscosity multigrade oils specified by the manufacturers to get into the bearing surfaces and have a degree of "cling". For that reason, I stick with them, particularly for classics driven for low mileages between periods of inactivity, although I know there are many who favour the modern synthetics.

 

Regards

 

Steve

[Clive]

Get the best of both words, a synthetic oil with a high viscosity......

But only worthwhile if you do drive the cars hard, most don't.