Longer oil change interval?

[McDuff]

I change mine every 3-4000 with a fully synthetic - dont switch to oil around town or short journeys and there is no hint of problems so far (touch wood)

[1958steveflying]

Historically I have done my oil changes annually however at 50 miles per working day (7 on 3 off, 7 on 4 off) my partner is starting to knock up the miles, I can see me changing hers twice a year.

[nathanrobo]

I've never seen or smelt anything in my engine oil out of the ordinary.  But has anyone here ever come across evidence of bio causing ring gumming.  I've always said that it doesn't AFAIK but I'd like to be more sure.

[nigelb]

I've never seen or smelt anything in my engine oil out of the ordinary.  But has anyone here ever come across evidence of bio causing ring gumming.  I've always said that it doesn't AFAIK but I'd like to be more sure.

Our two cars are running as well today on Bio as they ever have.

[greasemonkey]

I don't think Bio does gum the rings, any more than dino. Its the fact that veg tends to partially combust at low temperatures, and uncombusted bit turns to a gum that sits on the rings, and then bakes hard as the engine warms up.

[nathanrobo]

Thanks guys, thought that was the case.  I guess the absence of contrary info proves the point!

[kamaangir]

Hi Nathan,

After re checking the info on the 80 series it appears that I was wrong, the old 4.2 12v engine is an IDI engine, I was given this info from some one who is supposed to know about them!

I suppose it does happen to IDI's as well, but where it may happen to IDI's it definitely will happen to a DI if you run 100% veg and do short trips and or lots of cold starts.

I agree with others in that running bio does not seem to require as regular an oil change as running straight veg. I had my van about 1 year, (VW LT TDI) and did over 8k on bio and did not change the oil!

[Head Womble]

Some IDI will suffer from ring gumming when run on veg,
the MB OM606 and 605 are known for it (but for some reason the 606 more so).

As for oil changes, the wife's 406 has now covered just short of 85K on bio (185K total),
this is with a Bosch conversion with the timing set by ear (there's no data for a 1.9 pump on a 2.1 engine),
in that time it's only ever had one oil change a year,
we've had it almost 4 years so over 20K between changes.
it still only needs topping up once between changes and runs well.

But one thing that does concern me is the sticky buildup in the fuel lines,
I changed the one from filter to pump recently and it only had a small hole down the center, maybe about 2mm in a 8mm id pipe,
needless to say it was down on power.