Originally Posted by
rick130
Umm, no.
That's the sort of thing blokes did when I was a kid, (early seventies) and I still remember Dad's 'greaseologist' (that's what it said on his wall) telling him "that Shell oil was no good as it went black really quickly"
No, what that colour change meant was it had better detergency and dispersancy than the Castrol GTX we put in our Jeep and Holden's, it was doing it's job and cleaning and suspending stuff.
Colour with diesel oil for the most part means absolutely nothing, it generally goes black pretty quickly, even with the TD5, and as for texture, I was joking re soot %'s, but I'm damned if anyone can feel the difference between 0.5% (ok) and 4% (well past most peoples condemnation limit) and either is as black as night.
Yes, we can all smell diesel, but if it's at the point you can smell it in engine oil it's waaaay past the point it's doing potential damage.
No oil, regardless of cost nor pedigree nor additive level nor base oils can cope with fuel dilution (or coolant for that matter, glycol is an oil killer too)
A business card and a drop of oil will give you a quick and dirty visual reference.
If it spreads fairly quickly and gives a lighter outer ring like a 'halo' that's probably an indicator of fuel.
This is a great one for when you suspect but aren't sure (and you're waiting for the lab results)
Soot levels can be indicated in the outer ring, I'll try and dig up an example, there used to be an excellent Cummins reference I've posted before.
Old school GP's could tell a lot by grabbing your wrist, looking in your eyes and looking at your tongue, but looking at and feeling engine oil I don't think you can pick up too much.
