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Old 4th June 2019, 16:05   #11
Mike Noc
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Shame Robbberd's thread didn't end with the reason for his contamination problems. He did go through 5 oil coolers though, and none of them cured it.

Earlier you mentioned doing a pressure test - did the pressure drop over time?

It is possible that it could be a crack in the head or block, or HGF, but all of these are as good as unheard-of with the M47R.

Is the coolant strength correct - and no chance of it freezing over the last winter?
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Old 4th June 2019, 16:23   #12
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Unlikely but there could be a leak in the head gasket between an oil way and a water way.--------When hot the water under pressure could pass into an adjacent oil way.
Well I could be, but how to confirm that

As I said there is no oil/water mixed in the rad header tank.
Although there is a little scum on and around the filler cap
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Old 4th June 2019, 16:25   #13
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Shame Robbberd's thread didn't end with the reason for his contamination problems. He did go through 5 oil coolers though, and none of them cured it.

Earlier you mentioned doing a pressure test - did the pressure drop over time?

It is possible that it could be a crack in the head or block, or HGF, but all of these are as good as unheard-of with the M47R.

Is the coolant strength correct - and no chance of it freezing over the last winter?
This has only manifested itself in the last few weeks, And to be honest it has not been that cold over here, Also I previously changed the Antifreeze to a 50/50 mix.
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Old 5th June 2019, 04:16   #14
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What about a search on BMW forum?
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Old 5th June 2019, 05:56   #15
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I have had a general look. EGR cooler seems to a common denominator.
Have you got one of those?
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Old 5th June 2019, 07:02   #16
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I have had a general look. EGR cooler seems to a common denominator.
Have you got one of those?
No ,Not that I know to, it also has a EGR By Pass
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Old 5th June 2019, 07:37   #17
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Well the puzzle deepens.

I did a cold pressure test last night,I put pressure of 25 PSI into the water system left it overnight a total of 14 hours and checked this morning and there is NO drop in pressure.I released the rad cap and there was an escape of air.

SO How is the water getting into the sump??

Next thing I am going to do is swap the oil cooler and see what that does, And if that doesnt work then maybe its the end of the road for it.
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Old 5th June 2019, 07:41   #18
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Worth swapping the oil cooler if only to rule it out, but I have seen a suspected oil cooler failure on an M47R and the expansion tank was well contaminated with oil. As you have no evidence of that I can't see it being a failure between the pressurised oil feed and coolant channels.

It could be a failure of the head gasket or crack in the head or block leading to coolant leaking into one of the voids used by the oil to drain back into the sump.

Only way to find that would be a strip down starting with removing the cylinder head though.

A possible explanation as to to why the system retains pressure when cold could be that the crack opens up once the engine is warm?

Hopefully someone can come up with an easier to fix suggestion to your symptoms, I'm afraid I am out of ideas.






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Old 5th June 2019, 07:48   #19
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I have seen a suspected oil cooler failure on an M47R and the expansion tank was well contaminated with oil. As you have no evidence of that I can't see it being a failure between the pressurised oil feed and coolant channels.

It could be a failure of the head gasket or crack in the head or block leading to coolant leaking into one of the voids used by the oil to drain back into the sump.

Only way to find that would be a strip down starting with removing the cylinder head though.

Hopefully someone can come up with an easier to fix suggestion to your symptoms, I'm afraid I am out of ideas.
Thanks for the reply, But what I don't understand is If there is an HG problem or a crack in the Head, Block why did the pressure test not show this up?

I used a similar test rig as you showed.
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Old 5th June 2019, 07:51   #20
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Yes that is a bit of a mystery. I can't think of anything other than a crack which only opens up once the engine is warm.

Your symptoms seem very similar to Robbberd's, so whilst this is a rare fault, it isn't unheard of.

Real shame that there wasn't a positive conclusion to his thread.











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