Mayo in expansion tank

[Paul Philpot]

Car is 1.4 K series. 42,000 miles. White mayo in expansion tank. No loss of power, oil looks perfect (level and colour). Serviced 500 miles ago. Uses about 250ml of water every 500 miles.

Any ideas?

Paul

[K7 VCT]

Start of Head gasket failure by the sounds of it.

☹

[oilyhands]

It’s unusual to see oil in the coolant without also seeing coolant in the oil when suffering HGF. How old is the car/engine? Are you sure it is mayo?

Oily

[Paul Philpot]

1994 42,000 miles. Mayo? White gunk.

[K7 VCT]

Oil pressure is higher than coolant pressure ?

 

[SLR No.77]

Expansion tank or catch tank?

[Paul Philpot]

Expansion tank.

[oilyhands]

There are very few places where an oilway is close to the coolant jacket, just one in fact, Very early engines with plastic dowels and older style gaskets have a weakness at the front dowel which houses the only oilway at the level of the cylinder head, it is likely that the oil has leeched past the plastic dowel and breached the coolant seal, on post 98 engines this is not possible as the gasket design changed. Hence my question about the engines age. It is highly likely that this is the mode of failure.

Oily

[Paul Philpot]

So... New head gasket it is.