Flushing oil

I wouldn't.

Sump off first and check the strainer and o -ring.

I would not use flushing oil as it usually fetches the crud out thats been sat happily uptil now and blocks fine passageways.

Are you using a genuine Mahle (OE) filter with decent non-return valve?

Tim..

It'll f*ck it good and proper. The oil light is taking 5 seconds to go off because either the oil pump or the bottom end is worn. You can change oil as often as you want but it won't stop old engine designs from wearing - it'll just slow the process down.

Far better would be to fit an oil pressure gauge so you can see what is going on.

Seconded. For the reasons mentioned by others. Mike.

It won't do any harm, but it won't do any good either. Nor is it anything to do with a clogged strainer. The oil pump is worn, and oil is draining from it back to the sump when the engine is stopped. Short of fitting a new oil pump you won't change that.

Taking 5 seconds for the oil light to go out is no problem, the oil in the bearings makes sure that no harm comes to it before the pressure gets up. As long as the light goes out you'll be OK. The next stage is that the oil light will start coming on at tickover when the engine is hot, but this still isn't a major problem as long as it goes out when you rev up.

The engine smoke will have become a major problem before this does.

Steve

Thanks guys. I had a sneaking feeling it was a bad idea. I'll make do with very regular oil changes instead. The oil filter is made by Mann. Probably not got a non return valve.

Graham

Stick with the 5000 mile changes. Doing it every 1000 miles acheives absolutely sod all with modern oils.

I thought MANN were the correct filters for these VW engines. I thought Mahle made pistons and conrods etc..

Might be wrong though!

Mike P

Using a piston as an oil filter would explain it. Stick an oil pressure guage on it & see if it's supplying enough pressure, if it is leave it alone, if not you'll want to change the pump anyway.

Oil pressure is correct as per the workshop manual. Oil pressure does rise fairly slowly on these engines due to the large oil ways, but the oil light should go out almost instantly. It should go out when it gets above 2-6.5psi (0.15-0.45 bar). That is the point when the first oil pressure sensor switches. There is a second sensor will sound a buzzer if oil pressure does not reach (29psi (2 bar) at revs. I'll stick with running fresh oil through it very often, driving a few hundred motorway miles and changing as it is slowly improving every time I do this. Oil pump would cost a thousand to replace. Requires lifting the vast between seats engine out a fair bit, possibly completely and ithe pump aint cheap either. Even a pattern part oil filter is many hundreds. I am fairly sure its not the pump as this van has only done 76,000 miles. Its spent most of its life in a garage and only driven 6 weeks a year since 1993 and previous owner left the oil for 8,000 miles, which was at least 5 years. So it may have got a bit gummy in there.

Graham

Obviously, I mean "oil pump" ;-0

My Fiat's handbook explained that this was normal behaviour after driving the car hard...

Bear in mind this is a very large inline 6 cyl engine. Takes a while for oil to get around it.

Graham

On the other hand, a given engine will have oil pumps, filters and lines designed with this in mind...

If the strainer or oilways are gummed up then you won't get full oil pressure, so you're seeing the oil draining down.

Part of which includes assuming that you don't need instant oil pressure.

Mahle makes a wide range of filters, sold under both their Mahle and Knecht brand names:

John

Seconded. If it's a clogged strainer it's not going to magically unclog. Mine was clogged full of silicone sealant due...

I've had MANN and VW side by side and they look identical. The MANN ones have the same printing but without VW...