Engine malfunction warning

[Terri]

Hi all. I have got a 62 plate focus diesel econetic. Wondering if anyone can shed light on my engine malfunction warning light? It all started after having the car serviced. The first message was engine oil change, went back to garage and they said it was done on service, so they reset it. A month later oil change message came up with amber engine management light. Went back to garage, put it on diagnostics test. Came back with i dont travel far enough in the car! Ran the engine at high revs for an hour. Engine management light went out. Again month later oil change message came on and engine malfunction. We changed the oil, so now it doesn't say oil change but still engine malfunction with loss of power. Any ideas please before i take it to a garage to get ripped off again. 

[Tdci-Peter]

8 hours ago, Terri said:

Again month later oil change message came on and engine malfunction.

Check whether the coolant level is dropping. Water getting in to the oil might be one cause of frequent oil service warnings. Grey emulsion inside the oil filler cap or crankcase breather hoses would be a symptom of this.

Another possibility is frequent failed DPF regens. This can result in fuel getting in to the oil, and the oil level will rise. It won't look any different to normal oil, but is not as good a lubricant. If the problem is DPF related, the first thing to check before any expensive DPF cleaning or changing, is the condition of the hoses from the DPF to the DPF DP sensor. These are prone to cracking and leaking.

Some diagnostic systems are not good at detecting DPF problems. It may need a Ford specific system like the Ford IDS (for dealer/garage use), or like Forscan (for diy use).