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MG MG Y Type - XPAG Oil & Water Mix

I have an early XPAG with water in the oil AND lots of oil in the water. No water showing above the core.

In my experience you usually get one or the other, not both ?.

Can anyone suggest a failure point that could result in both (apart from sabotage) ?.

I will do a compression test later today & report back.

Thanks in anticipation,

Tony
A L SLATTERY

PEBS (Porous Emgine Block Syndrome) Tony?

https://www.google.com/search?q=porous+engine+block&ie=utf-8&oe=utf-8

Paul
Paul Barrow

The engine was rebuilt 15 years ago, so not a manufacturing porosity issue, so it could only be from corrosion, but I can't see any point where the corrosion could reach the oilways/sump cavity.

Time to pull out the inspection camera ?.

Certainly an interesting one........

Thanks for your feedback.

Tony
A L SLATTERY

Or buy a goldfish :)

(No animals were harmed in the making of this statement!!)
Paul Barrow

Tony,

In my experience, I have seen the oil and water go both ways. The way I suspected it happened was that, when the engine is running, the oil pressure was greater than the water pressure so oil goes into the water. Then on shut down, oil pressure drops to zero and the water pressure pushes the water into the oil passage.

I have had this happen with head gaskets and with oil coolers that used the coolant instead of air. I have also seen it happen with automatic trans coolers that were mounted in the radiator.

That said, none of this experience was MG specific. Also, I don't know if the XPAG uses a pressurized cooling system. But, with a bad enough leak it might not require the pressure.

Charley
C R Huff

I had a similar problem a couple of years back. The block had been re-bored and sleeved back to standard a few years previously. Then, mysteriously, water was getting into the oil. A replacement head gasket nor a pressure test on the head revealed the problem. Ultimately the source of the contamination was found to be water coming up between the liner and the block as a result of the machinist overboring the block by a couple of thou, breaking into the waterway and having to Glue the liners in! overtime, the liner moved and water found it's way into the sump and combustion gasses and oil were forced into the waterways. The source was noted as when the engine was started, the water level in the rad went up and bubbles started to appear (classic Head Gasket Failure, but it wasn't!) New, oversize liners were made, fitted (by a different machine shop!) and all was well for a time (that's now another story!!)
D P Jones

Just a thought, but there are three connected, but blind ended, drillings at the rear of the cylinder head that feed oil to the rear rocker pedistal. Internal water corrosion could reach any of these drillings, particularly if one was originally, by accident, drilled too deep. Thus oil pressure could push oil into the water, and with a stationary engine there may be sufficient head of water to push water into the oilway - and when stopping a hot TF engine there would be internal water pressure until the engine cooled.
R A WILSON

This thread was discussed between 04/11/2017 and 05/11/2017

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