Looking for advice from the pro engine builders

How you doing guys Andrew here, i am currently a light commercial vehicle mechanic based in Scotland, just looking for a little advice on diesel engines.

I constantly see vehicles that have came back in well past their ideal service mileage (despite our protests and advice might i add) and when we go to change the oil find it very very dirty and full of carbon, my question is what is the best way to combat this to extend the life of an engine and save the customer money in the long run? is the answer Oil Flush? Is it more regular servicing? is it a different oil i.e long life pd oil ? any and all advice is welcome.

Thanks in advance.

I remember talking to a Total oil rep about this, and apart from trying really hard to sell me his products, he did say that a low SAPS oil is better for this, aswell as being necessary for a vehicle with a DPF. I'd be interested to hear what anyone else has to say about this, as I have a pretty decent commute down to HPA labs every week, and run a 3.0 Diesel Audi which I'd like to keep in good nick :-).

What oils are you chaps currently using - IIRC, diesel oils have a stronger detergent pack (additives) to help keep carbon in suspension and parts cleaner, to be picked up bu the oil filter(s). For the most part, petrol/gasoline oils are generally not recommended for diesels because of that.

Second thing is the oil filter - most heavy diesel vehicles will have two filters, often a coarse 'pre-filter' for the larger particles and a second filter for fine particles that the first doesn't filter. That arrangement minimises clogging and maximises the filtering.

With automotive oil filters in diesels, you usually have Hobson's choice - OEM - unless you are able to take the time to check out what theother filter manufacturers can offer... remember, the finer the filtering, the greater the pressure drop across it, and more quickly it may get clogged and open the bypass, and if there is less filtering area...

Andrew, I applaud your concern for your clients, but other than replacing the filter each time, using a diesel oil of the correct viscosity and encouraging the clients to change their oil as per schedule - you could point out that when on-sold a good FSH will add more value to the vehicle - there isn't much more you can do.

Zac, one of the worst things an oil has to put up with is slow town driving and cold starts whereas sustained open road driving at operating temperature is close to the best, so other than using a good diesel oil and changing filters each service, you should be fine. I don't know about other weaknesses/problems with those engines but you should be looking at 4, 5, 6 or more hundred thousand kms from the vehicle.