I have just found this site a few days ago, wow what a great place.
Many years ago, I read that using diesel oil works well for flushing engines. The article claimed this oil was very high in detergents. The idea was to run the oil for a week or two, drain and refill using your favourite brand.
Is there any truth to this idea?
I discovered this site due to the horror of checking my oil level, and finding it very low removed the cap to see black sludge coating everything. I was shocked and obviously I need to do something. The car is 9 years old and has done 155,000 miles. The oil itself is black and similar to treacle.
I drive about 80 miles a day at between 60-70 mph. I always thought sludge was related to driving stop-go city driving over short distances.
Sorry for the long rambling post
Steven