I have recently had a number of issues with my car's engine, which I suspect could be related but wanted to get some thoughts here on whether they are, and what the root cause could be, before I start pulling the engine apart.
The car itself is a UK spec 2011 Ford Galaxy with a 1.6 Ecoboost engine (petrol, turbocharged).
The first problems I noticed are a rough idle, particularly when starting from cold, often with a noticeable grey smoke cloud from the exhaust as the engine starts. It also sometimes feels as though the car struggles to start, although so far I've had no starting failures.
I've also noticed the coolant level seems to be slowly dropping. In particular it will often drop below the minimum level, and then opening the coolant reservoir cap will cause an audible release of pressure, along with bubbles rapidly flowing up through the reservoir and the coolant level rising again. Overall then the level after opening seems to be slowly going down over time though.
I've also had the spark plugs out to try and investigate this, and noticed a small amount of oil on the threads towards the top.
I have a basic OBD2 reader and the Ford specific ForScan Lite software which shows a possible fault with the turbo wastegate actuator. Other than that then no other fault codes are shown, and the engine management light is not on. I did use the software to run some monitoring and this showed that the throttle position sensor seemed to be fluctuating during rough idle.
Can anyone advise as to what could be causing this, and any further investigations that might be necessary?