Bits of dipstick broken off

[Dieselman]

That glued on piece looks like a magnet.

I think you are changing your oil too often, it's unnecessary and fresh oil gives less protection than partially used oil.

Go synthetic and double the drain period, alternatively fit a bypass filter.

[endorfin]

You're right, it's a magnet! What's the purpose of that, I presume to catch metal particles, do they work?

As for changing the oil often, I run my car on filtered vegetable oil and its advisable to change the oil more often to avoid polymerisation of the engine oil. Although this is less likely on the indirection injection 2.5 engine than it would be on direct injection diesels.

[Dieselman]

I agree about the risk of polymerisation so understand now.

Why not run it on vegetable compatible oil?

[endorfin]

I don't think there is such a thing, if there was I'm sure I'd have read about it on the veg diesel forum, we talk about polymerisation at length. I use mineral oil meeting specs API SL/CF, ACEA A3, B3, no point using expensive fully sythetic oil when its changed frequently, I believe the engine was originally designed for mineral oil. There was a very interesting discussion on the results of research on semi-synth oil where it was found it had no benefit over mineral oil in fact it was worse for the engine. Can't remember the thread but a search should turn it up on http://www.vegetableoildiesel.co.uk/forum

Generally IDI engines are low risk to polymerisation, its the DI engines that are more of a concern but I change every 4k miles as a precaution. The fuel savings I make more than covers the cost of the oil changes.

[Dieselman]

There is special oil, I just can't find a link to it right now.