How can you tell if the garage really put new oil in your engine? (- It looks black just like the old oil)?

Question

I have reason to suspect that I was charged for an oil change that never happened. I have taken it to another garage to look at and they said that in a diesel engine, after only a few hours running, it is impossible to tell if the oil is old or new. Does this sound right or is the brotherhood just closing ranks?

Answer 1

well the only way to really tell is to look at the oil filter and see what kind it is. Unless you have the new Ford Diesel that takes a canister. But any way I own and operate 3 quick lubes and we do about 150 cars and trucks a day between the 3. We have a lot of comercial accounts that bring in diesel trucks. The only Diesel engine that I have ever seen clean oil in after an oil change was the Dodge cummings. All others look just as black after as they did before. Diesel engines create a lot of soot. It is completly normal to have what you are describing. But if you are unsure then get it done somewhere else that you trust.

Answer 2

Diesel engine oil does turn black a lot sooner than gasoline engines. But it should not be all that dark in just a few hours running. They can analyze the oil and give you a very close time frame (in hours) since the oil was last changed.

Answer 3

There is speculation that some new motor oil is actually reconstituded used oil. [the jury is still out on this one...]

With a fairly clean engine [internally] the oil should stay clean looking for hundreds of miles.. as opposed to a grunged up engine [internally] the fresh oil would blacken fairly quickly...

--------------------------------------
I had a garage change my oil one day.. and the engine began to tap right away.. I called the garage and they said they used NAPA brand motor oil to change the oil.

Interesting enough I had the engine oil changed elsewhere with a different brand.. and the engine mysteriously stopped tapping.

Did this help any?

Answer 4

I've seen new oil turn black after just a few minutes of running. VW's where the engine tilts back are great for this since an amount of old oil always manages to stay in the engine.

Answer 5

This can be true. If you have not changed the oil at every suggested time point, then yes. There is black sludge build up in the oil galleys, passages, and block which gives you that black burnt look. If the oil was changed at regular time points is still might have a hint of black too it, but you would be able to tell if it's newer. It would have a clearer color to it.

Answer 6

In a diesel engine the oil turns black really quick, it mainly gets it's coloration from the residue oil, left in the nooks and cranny's of the engine that won't drain out and the film left on the interior, So after a few miles of driving it mixes and turns black.

Answer 7

i own a repair shop,and it shouldn't look black,,it should at least stay clean for a few hundred miles ,in the car,,there's a good chance they might not have changed it,,because most oils now days,will stay clean for a while anyway,i change my one,,and a lot of other peoples also,,and i have never seen it turn back to black that fast,,id ask them about it,,maybe they didn't change it,,who knows,,but id talk to them about it,,good luck hope this help,s

Answer 8

id suspect it wasnt changed. it should stay coloured for a few days. the prob with this is if it wasnt changed you could damage your engine

Answer 9

just to be sure change the oil yourself if you can do that

Answer 10

I watched my man open,yes with a snap,snap,,,,,,,,the container and pour nothing but full synthetic.Only way.