FIAT Ducato autoking 630ck - Excessive crankcase pressure

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Wed 22 Jul 2015 19:43
FIAT Ducato autoking 630ck - Excessive crankcase pressure - Littlebillwhite

Hi, newbie here, hope someone can help...

Last year I had 2 x pistons replaced due to overheating. Drove away from garage and oil light was flickering occasionally when braking or going around corners (thought this was just faulty electrics or just general age of vehicle). Got it home (200 miles from garage), left it for a while, took it for MOT and oil was coming out of Rocker gasket, since fixed. Now the garage who fixed that (rocker)have said there is excessive crankcase pressure. Rang the original garage and asked if this was covered under warranty (due to engine rebuild) and all they keep saying is that I shouldnt have driven it if the oil light was flickering. Question is - Would low oil pressure lead to an immediate problem of excessive crankcase pressure which wasnt there before they rebored the engine?

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Wed 22 Jul 2015 21:54
FIAT Ducato autoking 630ck - Excessive crankcase pressure - Peter.N.

The short answer is no. Bearings are what will fail with no oil presure so if you have no rattles or rumbles in the engine it should be OK. Mind you if the oil light was coming on when cornering that is a pretty sure sign that the oil level was low - the quickest way to wreck an engine. At the first sign of an oil light the level should be checked.

You can get sudden bearing failure but not sudden piston/bore failure unless the engine seizes up. I would suspect that you have failure of one of the other pistons as a result of the original fault. I am surprised that the garage didn't reccomend replacement of all the pistons at the time.

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Thu 23 Jul 2015 00:39
FIAT Ducato autoking 630ck - Excessive crankcase pressure - Littlebillwhite

Thanks Peter, that is very helpful.

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Thu 23 Jul 2015 10:41
FIAT Ducato autoking 630ck - Excessive crankcase pressure - Littlebillwhite

That's interesting, thank you. Would there be a noticeable noise/effect of piston ring failure? and is it likely that the piston ring would be caused by low oil pressure or is that just too hard to say

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Thu 23 Jul 2015 10:54
FIAT Ducato autoking 630ck - Excessive crankcase pressure - Peter.N.

I would agree that piston ring can occur suddenly if a ring breaks but its unusual. Failure of pistons or rings is unlikely to have any effect on the oil pressure.

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Thu 23 Jul 2015 11:24
FIAT Ducato autoking 630ck - Excessive crankcase pressure - Littlebillwhite

When I got it back from the garage that did the rebuild/re bore of 2 cylinders, there was a huge amount of blue exhaust fumes every time I started the van. The sort that engulfed the van (a bit embarrassing starting up on the street tbh), which didnt happen before the rebuild. The garage also didnt re attach the breather pipe after the rebuild, just left it hanging (one end came off when the van originally overheated) - couldnt understand the reason why they didnt do that

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