Yes I know about that but the fact remains that if the oil was changed more frequently it wouldn't get sludgy enough to clog the turbo feed filter and reduce if not alleviate the problemKozmoNaut wrote:The 1.6 HDi had (has?) a well-known design flaw. It has nothing to do with long oil change intervals directly or the total amount of oil in it, the real problem is that the original sump design doesn't drain correctly. There's plenty of oil in it, but every oil change leaves the dirtiest nastiest bits in the pan, because the drain isn't at the lowest point, for some unfathomable reason.PeterN wrote:I'm not talking specifically about 406s I agree the turbo's dont fail in them, but there are hundreds if not thousands have failed in the 1.6 Hdi engine both in Citroens and Fords. The oil change intervals specified are far to long and the sump to small.
Normally, this wouldn't be a problem resulting in catastrophic failure. It would just reduce the service life of the engine/turbo a bit, were it not for another design flaw or oversight. The banjo bolt attaching the turbo oil feed line to the block has a small mesh filter in it. This is to protect the bearings in the turbo from gunk and particles, in order for them to last longer.
The combination of a bad sump design, the filter in the banjo bolt and a fluid-bearing turbo causes the turbo to be starved of oil, and no turbo can survive that for long.
A quick fix is to remove the mesh filter from the banjo bolt. Of course, this causes more gunk and particles to reach the turbo's fluid bearings, but instead of catastrophic failure, you will have plenty of noisy whistling warning before it finally lets go.
The proper solution is to fit a redesigned oil pan that drains properly. Or you could drop the pan and clean it out manually at every oil change. I know which option I prefer :-)
You have to remember that back in those days, engines were built with much looser tolerances, diesel was far dirtier and engine oil was closer to raw crude oil than the advanced synthetic oils we use today.I have been running diesels since 1959 and I have never had a turbo fail although the early ones didn't have them but the oil change intervals were 2,000 miles with the early Perkins engines and subsequently 6,000 although I used to change mine at 5k, it was easier to remember. I also have had diesels XMs with 300k on them and original turbos but we are talking about modern engines.
Peter