Mondeo 2.5T engine oil horror show

[DE018]

I recently bought my latest car, an 07 plate Mondeo 2.5T, with the Volvo 5 pot 2.5l Duratec engine. The previous owner was an old giffer who only drove it at 30 to the shops and to church on Sundays, hence he sold it. He'd apparently never heard of these things called "services" because the service book was blank and the receipts I got with the car had nothing for the past 4 years, aside from a set of front brake pads.

So, all has been well for the 4 months I've had the car, and it's been to the stealer for a full service, which picked up no faults whatsoever. However, I was driving last week when the engine started making noises which instantly told me something was amiss.

When I got home I quickly found that the problem was the PCV diaphragm failing, which is a common problem with this engine, and there's loads of information about cause and cure.

Being handy with a set of spanners I set about changing the oil filter housing. The job itself isn't too bad but when I got the housing out I found the lowest oil port completely blocked with crap. And I mean it was caked in the stuff. I used a bottle brush to scrape what I could find out of the port of the block, replaced the housing, and the engine runs fine now.

I'm slightly concerned that there is still some solid sludge floating around in the engine so I'm going to change the oil and filter every 1500 miles a few times to try and flush out the crap.

One of the guys in work suggested using an engine flush product to assist in the crap removal. I've always thought these were snake oil, but I've also never seen as much sludge in an oil system, so would it be worth using a flushing solution, or should I just stick to regular, short interval oil changes for a while?

[steveo3002]

flushes arent snake oil , but once you loosen all the baked on stuff it might do more damage on its way round the engine

i think i would stick to regular oil n filter changes , if you have the ability then rocker cover and sump off for a clean wouldnt be a bad idea and will help give an idea of how things are

[liquidfox]

If you've replaced the oil filter housing it would be worth replacing the breather pipe too, the original is plastic and tends to become brittle and crack causing further problems. The revised part is rubber.

[Petrolhead_Rich]

Most services I chuck a can of THIS in, leave the engine idleing for 5-10 minutes (on ramps ready to drop the oil), then engine off, oil out whilst it's still hot, it does involve some "ouch that's hot", but does also clear all the crap out.

Given the history & know s**t in the engine, the other option would be to buy a few cans of cheap oil and with the drain plug removed, keep filling from the top, thus flushing the engine through. (not running!)

As a warning, I had an S60 with the 5-pot engine that decided to eat its big end bearings, at that point it's new engine, so with that in mind the cost of a few cans of oil and/or a partial stripdown & clean (sump off/rocker cover off?) would be well worth it IMO.

[Dr Doofenshmirtz]

Drain the old oil then refill with a 50/50 mix of el cheapo engine oil and regular (Homebase etc) paraffin.
Run the engine at idle for 10 mins then leave to soak overnight. Drain and repeat.
Change the filter and Fill with good oil, then change filter and oil again after 3 or 4 hundred miles. Job done.