The Darndest Thing...

G'day All,
last week a carpenter mate of mine, asked me to go with him to look at a 1978 Caterpillar D4D bulldozer he was thinking of buying.
I was racking my brain to try to think of all the things to check for,on
the old girl from my diesel fitter days,when I pulled the engine oil dipstick.
I was checking for the level and also for the colour and that there was no water in it.
I noticed the oil looked crystal clear, so I inquired from the 82 year old owner if he had just changed it. He replied " No its about 4 months old "
When I commented how new it looked he replied " Caterpillar engines don't dirty their oil" My experiences with used diesel engine oil is like model T fords as Henry Ford said they come in any colour... as long as it's black.
I also thought one of the functions of diesel lubricating oil was to carry away some of the soot that is a byproduct of diesel combustion hence the need for frequent oil changes.
The engine hours were unknown as the hour meter was unreadable, but the owner said he had never had it rebuilt. The exhaust stack blew nice and clear too, and it ran very well.
This is a bit of a mystery to me, as I have never come across it before.
Any comment on this or any other brand of diesel engine that does this too?
regards Harleigh.

ive never seen "clean" oil come from a diesel engine . . more likely that the oil he is using isnt doing its job (maybe home brand oil lol )

Dodge
GuddayM8
Most modern diesels run a detergent oil to wash the carbon from the cylinders n all the good bits So ifn U're C@ oil aint black this could mean the carbon is buildin up iside the doingz
But
Wot Dew eye no
LOL
U need advice from our resident Ch@erpillar Guru from the Left
his consultations fees can B very modest @ times
so Over 2 U
OsDozer,OzPozer,JuanTrak,OneTrack
LOL

Cya

[ch9787]

Harleigh - "Caterpillar engines don't dirty their oil" ... ??? What planet is this bloke from?? ALL diesels dirty their oil as soon as they've run 10 hrs .. and Cats are best at it. This bloke has filled her up with some cheap K-mart oil on special .. or some re-cycled oil with all the additives taken out ..

I'd be very wary of what this bloke is trying to pull. Maybe he's just changed the oil yesterday, to eliminate the tell-tale signs of metal, water, or other contaminants. I'd be treading carefully.

Detergent oils have been in existence since 1935, when Cat went into a huddle with Chevron and Texaco over huge problems that Cat were having with piston and ring gumming, and varnish buildup, in Cat diesels. They found that a naturally-occurring detergent in oil, had been removed by a new refining process. Thus, the oil companies starting adding detergent and other additives to keep control of carbon, varnish and gum buildup. Cat set the detergent diesel oil standards, and everyone followed.

All diesels MUST use detergent oils, because of the massive increase in pollutants in the engine, due to the fact that diesel is not as refined as petrol. A diesel oil getting dirty, shows its doing its job.
Clean oil in a diesel engine, particularly a Cat dozer, after 4 months of regular use, would ring alarm bells with me. Maybe he has done very little work with the D4D since changing the oil??

being a farmer he mite of put canola oil in it [smiley=2vrolijk_08.gif]