Oil - synthetic after mineral

[DevonMark]

It seems that any questions relating to oil choices can get people's backs up on here, so before you read on I can assure you that I have read the Wiki!

The thing that's worrying me is that the Wiki says using mineral oil after synthetic oil (or visa versa) is a bad idea, but as our van is new to us this week I have no idea what oil the previous owner has been using.

How much damage could I do if I make the wrong choice?

[Ian Hulley]

You don't say what engine ? But if it's a 1.9/2.1 watercooled drop the oil and replace with 4.5 litres of mineral 15/40 and a Mann oil filter ... simple as that really. It's what VW recommended at the time and it still works just fine for those of us who use their vans.

Ian

[DevonMark]

Hi Ian - yes it's a 1.9 water cooled engine.

So just get rid of the oil thats in there now and start again?

[KINGPRAWN]

Exactly what I have done today (2.1)... Perhaps the fuzzier of soon will be gone for good now?

[sarran1955]

Hello,

None...

Change oil, change filter

15/w/40 mineral (I use diesel grade cos it keeps the motor clean), Supermarket brand.

Check regularly for leaks.

Drive it and have fun...

Cordialement,

[DevonMark]

I'm about to reveal what a mechanical novice I am, but is it always necessary to change all of the oil every time?

I was under the illusion that topping up the oil would gradually 'change' it over time, hence my concern about mixing mineral and synthetic...

[sarran1955]

Hello,

Yes..all the oil,,,

New filter, Mann or Knecht.

New sump plug crush washer.

Why is there oil loss...

Do you have leaks..

What engine type, and photos are good.

Cordialement,

[AdrianC]

I'm about to reveal what a mechanical novice I am, but is it always necessary to change all of the oil every time?

It's not easy to only drain some out of the drain plug...

I was under the illusion that topping up the oil would gradually 'change' it over time

If you've got that big an oil leak, you've got a problem with your engine - sort that first. Our 2.1DJ doesn't need any oil adding between changes (10k km/6k miles), despite having around 270k km on it.

hence my concern about mixing mineral and synthetic...

There is no problem. Just drain, and put whatever oil you want in. There is no problem whatsoever in replacing one with another. Different viscosity, different base - just change it and get on with life.

[California Dreamin]

You are correct in that there are various opinions, most are based on experience and are valid in some way or another.
However, the debate regarding mineral versas semi synthetic when used in our older engines is not as clear. Some users have suggested that certain additives in synthetic based oils may lead to seals leaking and the loosening of carbon deposits which may lead to increased oil consumption but as I say, these are opinions and not necessarily fact, and the implications of using synthetics would vary greatly depending on age/condition and how well maintained the engine has been in the past.

Of course users come onto this site for just that, advice from people who actually own and run these old buses. It doesn't make sense to ignore other peoples experiences as often they will know better than 'the book' . For example, if you just looked on the oil charts in Halfords they would be having owners using very unsuitable light weight multigrades.

But lets not over dramatise, your engine isn't going to blow up or leak like a torpedoed boat just because you use the wrong type on lubricant, the choice isn't as critical as all that!

The main issue with choosing oil for the flat four petrol engines has always been picking the right viscosity (thickness), too thin and the hydraulic tappets will clatter for the first 15 minutes of every journey. The main advice is still mineral 15W 40 changed often, not necessarily with a new oil filter every time.
Some change the oil every 3 - 4 thousand miles and if thats you then you could change the filter every other.
If you leave changes to 5 - 6K then change the filter everytime.

Top Ups between services..try and use the same lubricant but again this isn't critical as is mixing semi with mineral but stick to mineral if you can.

Martin

[DevonMark]

Thanks for all the advice and help.

Just to clarify, there is no leak/oil loss - its just that I only bought the van this week so want to change the oil just in case it hasn't been done recently by the previous owner.

[AdrianC]

Just to clarify, there is no leak/oil loss

Ah, OK - your comment about "topping up" made me think there might be.

its just that I only bought the van this week so want to change the oil just in case it hasn't been done recently by the previous owner.

DEFINITELY! First thing I always do on any new purchase - no matter what - is a very, very full service. You never know what's been neglected before, and it'll help you get familiar with the van and spot anything else that might need doing. Ask somebody that knows their way around these vans to have a good look over it, too (Ian Hulley had a good look over ours when we happened to be up his neck of the woods, and spotted a few things).

So change coolant, oil & filter, air filter, brake fluid, plugs & leads & cap, at the very minimum, plus have a good crawl over everything you can. Get all the wheels off and have a good look at the brakes. It might make you miserable as sin, and it'll certainly hurt your pocket just when you don't want it to - but it's gotta be better than your first impressions of life-with-van being constant breakdowns.

[California Dreamin]

As Adrian C has said...it pays to spend 2 - 3 hours as a new owner, carefully looking around the bus and writing down your list of 'to do's' in order of importance.

Definately..service.
Oil filter
Oil /sump washer
Air Filter
Petrol Filter
Spark plugs
Gearbox oil (75W 90) semi synthetic GL4/GL5
Coolant change
Fan belt
Wiper blades
Screen washer
Battery levels if removable tops

^^^^^^^^^^UNLESS THEY HAVE OBVIOUSLY BEEN DONE RECENTLY^^^^^^^^^^^^^

Then your checks to the rest of the vehicle****

Brakes/flexis/pipes
Steering
Suspension
Tyres
Lights
Fuel lines
Coolant hoses
Exhaust
General wiring if things have been messed about
Interior/Camping accessories

Etc etc

Martin

[Ian Hulley]

As Adrian C has said...it pays to spend 2 - 3 hours as a new owner, carefully looking around the bus and writing down your list of 'to do's' in order of importance.

Definately..service.
Oil filter
Oil /sump washer
Air Filter
Petrol Filter
Spark plugs
Gearbox oil (75W 90) semi synthetic GL4/GL5
Coolant change
Fan belt
Wiper blades
Screen washer
Battery levels if removable tops

^^^^^^^^^^UNLESS THEY HAVE OBVIOUSLY BEEN DONE RECENTLY^^^^^^^^^^^^^

Then your checks to the rest of the vehicle****

Brakes/flexis/pipes
Steering
Suspension
Tyres
Lights
Fuel lines
Coolant hoses
Exhaust
General wiring if things have been messed about
Interior/Camping accessories

Etc etc

Martin

Fuel filter as well of course


Before our main long distance holiday (by coincidence midway between MOTs) I have a pre-MOT check done on The Bus by a very thorough local garage, one of only 3 people I trust to work on the mechanics of it.

Ian

[R0B]

Worth a mention.If it has a fuel filter in the engine bay.Get rid of it.The only one it needs is the one just after the tank outlet.