We bought a 2010 MINI Cooper Automatic as a spares-or-repair job for £1,000 off eBay. In this video, we reveal what we actually got — and how we turned it around to become a sellable car.
The Shocking Discovery:
When we opened the oil filler cap, we found the engine full of “mayonnaise” — a creamy mixture of oil and water. This was caused by a rusted-through core plug in the cylinder head, allowing coolant and oil to mix. Despite this, the engine still ran (barely).
What We Did:
- Removed and reconditioned the cylinder head (replacing the defective core plug in the process)
- Replaced the piston rings and big end bearings
- Fitted a new timing chain kit
- Performed a full flush and clean-out
- Reassembled the engine and ran diagnostics
FAQs
What causes “mayonnaise” in the engine oil?
Moisture mixing with oil – usually from a failed head gasket or, in this case, a rusted core plug.
Is this a common fault?
Not common, but we’ve seen it before. These core plugs can rust through over time, especially if the coolant system hasn’t been maintained.
How much did the repair cost?
Parts and labour brought the total to around £2,900, making the total investment about £3,900.
Was it worth fixing?
Yes – the car was sold for a profit, and the buyer got a properly sorted MINI.