engine flush - P 2501
I was thinking of using an engine flush when i next change my oil (97 306 xtdt) is there a problem with over filling if the oil is already up to the max on the dipstick? or will the small volume of flushing oil make no difference?
engine flush - sean
Yes, dipstick is what I'm thinking here, my friend.

To use engine flushing oil you drain all your old oil out. You then fill to the correct level with the flushing oil and drive for the requisite mileage, then drain it and fill with your normal oil to the correct level.

Are you sure you want to use flushing oil, and not some fancy additive?

Please tell us more.
engine flush - Crinkly Dave
The guy said "engine flush" not "flushing oil", Sean. You owe the gent an apology.

It is a sort of detergent solvent added to the oil just before the oil change, and the engine idled for 10-15 minutes. Can clear out quite a bit of crud, and not really necessary. If the engine is badly soiled it could release a lot of crud into the system all at once.

Better to do a normal oil change, and perhaps do it more frequently. Wynns and several others make them. In fact Wynns do different types for petrol and diesel engine

Perhaps best avoided, if like my Fiat the engine keeps a pint of oil in the cooler etc how ever long you leave it to drain.

engine flush - sean
Hiya Crinkly,

What DO you mean? I was thinking about his dipstick. Oh, all right then. I can't get near the screen as my nose has just grown.

Look, please don't use some fancy additive.

One of the main functions of oil is to hold nasties in suspension.

My PhD was in oil rheology so I used to know 1 or 2 things about it. Look at the detergent loading in diesel oils and you'll see that preventing metal to metal contact is not the main function of oil.

No. Get some nice thin flushing oil. Do what I said in the first bit and your engine internals will be lovely and clean.

I DO apologise if I need to. It's my medication, you know!
engine flush - Anglesey Ian

Don't worry about your slight relapse!

You do a wonderously informative job for backroomland
in the main.

One 'threader' referred to you as the 'VW Guru'


engine flush - sean
Please don't upset me by accepting me.

I'm a yorkshireman and we're a bit rough and ready.

VW GMBH know that I come here but the views written are entirely my own.

I have backup to resources which can help us all.

It is TRULY difficult to help people as, a cut finger at my behest, is at least partly my fault.

Many times I have wanted to supply advice but was told, simply, not to.

Use me as you wish. There are more of us here than you might think.
engine flush - Ivor E Tower
OK then, so what about flushing the VW PD TDI engines? Is this best avoidedat all costs?...and is GTX Magnatec OK, or Magnatec GTD for diesels? (I don't have the latest variable service interval engine so don't need to get worried about SLX II !!!).
engine flush - sean
Hi Ivor.

The Pd's really DO deliver at least their rated power outputs.

Put one on a rolling road and be TRULY impressed.

Dr Pietch wanted nobody looking at his work and giggling.

If you only get 150bhp from a TDi 150 I'll be sacked.

To deliver this, we had to push frontiers.

To do that, we required specialist oils.

You know exactly what your oil needs to be, don't you, my friend?

If you economise on that oil, you will suffer. Truthfully, you will regret it. Spend as much as you can, on the right oil. You know precisely what the dpec is, don't you? I went out of my way printing it in the handbooks. Deny it at your peril.

Think about 1 bar. 15psi. Think about 800 bar. 12000psi. Crackers pressures. Look at your efficiency, atomisation etc.

This is a well thought-out design.

I am the project leader.

I welcome your comments.
engine flush - P 2501
I was referring to the smaller bottles of engine flush (wynns etc) which crinkly dave mentioned. However, if you do not recommend using them sean, and consider them a waste of time/money, then i will heed your professional advice.
But you are quite right,I have been known to be a bit of a dipstick on more than one occasion.
engine flush - sean
Duffy, I am very sorry. Please forgive me.

You would think I would know by now that what seems witty one day seems quite offensive the day after. Clearly, I don't.

The reason I don't like the additives is easily explained if you compare your engine to a washing machine.

Put dirty clothes, water and detergent in. Let it agitate and the detergent suspends the dirt in solution. This is then rinsed away to give clean clothes and washer.

Consider your engine oil to be the water. Let it get very dirty. if you add more detergent, ie the additive for your oil, it will remove more dirt but nothing like as much as clean, fresh water would.

This is why I recommend proper flushing oil, or just good quality oil, frequently changed and no flushing.

And again, sorry. I sometimes wonder what is wrong with me.
engine flush - P 2501
No need to apologise Sean - I have been called worse things than a dipstick in the past!

I have only recently become interested in cars and maintaining them, but sites like this make it alot easier for novices like me to learn things.

Your explanation regarding engine oil changes cleared the subject up for me perfectly, as did crinkly daves comments.Thanks for these bits of info, i will remember them.

As this was my first posting on this site (and on the internet in general!)I suspect my original post was either not clear or incorrect,or possibly both.

I must also add that i find your background and employment history very interesting- amazing that we can all receive advice (free!) from someone who holds such an important position in the automotive industry.

Thanks again


engine flush - sean
Thanks Duffy,

The fact that you are new and were abused by me is telling me that I have not given you the standard of service you should expect here.

I have been told at work that a day will come when I will say just the wrong thing to just the wrong person, and regardless of past achievements, all will stop.

I posted another thread in the Discussion forum that went along unplanned lines and I caused great offence.

I do not understand people. Time to disappear for a while.

Thanks for your forebearance and understanding, my friend.
engine flush - Nortones2
I deduce therefore that you are a former or even current denizen of the Institute of Tribology, Leeds Uni, and claim my prize of a litre of Castrol's finest:) By the way, I came across the Mufti paper (Leeds again) on analysing valve train friction, which I guess has relevance to your PD work. Sooner valve springs are replaced the better! I make no claim to be knowledgable about such matters, only being a law grad. Albeit from Bradford, originally.
engine flush - sean
Nortones or Sherlock Holmes?

Very well done Sir. Spot on.

No hiding places left now.
engine flush - John S

Does your PD engine need the 'clever' 505.01 VW spec oil? If so don't use SLXII - according to the label on a can it specifically mentions that it does not meet the 505.01 spec.


John S
engine flush - Ivor E Tower
No' mine's about 2 and a half years old. I've already sussed that SLX II is not suitable, and I have even spoken to the helpful Castrol Technical number. I always use the best oil, and was very surprised to find that SLX II was not suitable - hence calling Castrol.
engine flush - Aprilia
Can't say I agree with the use of any flushing agents, assuming engine is running OK.

If its clean then you don't need to flush; if its dirty then flushing agents will just stir up all the muck (that's been quietly sitting in the corners for years) and may cause blockages etc. Oil pickup strainer in the sump is a favourite for blocking up after a flush.

"If it ain't broke then don't fix it"

Value my car