How to check if oil has been replaced during maintenance

[BartW]

Just got the boat back from the volvo dealer for the yearly maintenance.
On the invoice I could see the filters, labour and accesories, but no oil. Checking the engine oil it looked a little black.
I called the dealer and he told me he was 100% sure that the engine and drive oil has been replaced, they forgot to put it on the onvoice.
As I want to keep the engines and drives in top shape I am suspicious that I am driving with old oil. Is there an easy way to check this ?

/forums/images/graemlins/confused.gif

 

[gjgm]

an oil analysis would do surely.
I m guessing that taking the oil out through the dipstick might leave some old oil in there, which might taint new oil a bit. Still, should be easy to tell year old oil from fresh?

 

[DAKA]

I would expect to see streaky oil.

Golden brown goes in and mixes with the old black, until you have covered 50nm the streaks will not mix.

I cant imagine the filters have been changed with out the oil being changed.
Study the filters, try and spin one off by hand, it should easily spin 1/4 of a turn.
If both filters are too fast to undo then you should assume the oil/filters may not have been changed, contact Trading standards who will pay for an oil analysis.

ALWAYS ALWAYS
Mark filters, paint rocker nuts, impeller screws and ask for all old parts to be put in a plastic storage box you leave in the cockpit, then just check for your marks/daubs of paint, I know it is a little inconvenient but when your are climbing out of a trough you will want confidence in a well serviced engine and having a worthless invoice that you paid £1000 for will not help.

 

[mainshiptom]

The smell would give it away, old oil smells new does not !

Tom

 

[robyonfrome]

I was disapointed to see that my oil was still dirty black after I changed the oil, cant get every drop out, unless you drain from the sump plug.

 

[[2068]]

Old oil is Black.

And after draining all the old oil, replacing the filter, refilling with new stuff, running the engine for a few mins the new oil will be: errm, Black.

But not as Black as the old stuff.

I've just re-read the above, and it isn't amazingly helpful.

Sorry.

 

[piperdog]

if a diesel,then new oil normal turns black after a couple of hours running

 

[robyonfrome]

so why isnt the car oil instantly black after a change.

 

[gavina]

I had someone swear blind that the shaft anode had been replaced on my boat before they had launched it - one year later new folding prop needed!

 

[Refueler]

[ QUOTE ]
The smell would give it away, old oil smells new does not !

Tom

[/ QUOTE ]

Is that true ? Funny that - better dump the stocks I have then ... it's all old boys !

Would you mean that old oil has a different sharper taint to it than fresh new ?

 

[[2068]]

I suspect he means that used oil that is loaded up with acid and soot smells different.

 

[omega2]

One sure fire way to ensure this is DIY!!

 

[gjgm]

i think because you fully drain it out of the bottom of the sump, as the car is on ramps. Cant do that on a boat.

 

[robyonfrome]

I think gjgm that has to be the answer to the original problem

 

[DavidJ]

My engines (KAD43's) capacilty is 11 litres. I suck the old old oil from the dip stick (not literally). It takes 10 litres new to bring it up to the dip stick line, so conclusion is I have 1 litre of black stuff to mix with the new golden stuff to quickly turn it black as well. I think we all do so few miles that it's a bit academic to try and achieve a 100% oil change by removing the sump plug (and somehow getting it out!)
In short, black is what you get!

 

[DAKA]

I agree you will have dirty oil in there, possibly not as much as a litre as some will be removed with the filter.

The dip stick tube fills from the bottom with clean oil as at this stage the dirty oil is not mixed.

even when the engine is run there is no movement in the dipstick tube until the engine gets hot .

The dip stick should show clean oil streaked with black oil for a long time, there is no reason to run the engine to working temperature after an oil change.

Your dipstick should show clean oil if it has been changed.

The best indicator are the filters, they should easily unscrew by hand.
If they are stuck and start to deform then there is a very good chance they have not been changed and oil will be old.

You do not have to remove the filter to check, you can unscrew it half a turn and simply screw it back on.

no mess , no harm.

 

[Refueler]

Surely it is going to be hard to have nice brown green oil after a change. Even if you drop a sump plug - clingage round valve gear, crankcase, shafts and bearings will be enough to blacken any oil. Only way you'd get close to stopping that and then it would only be a partial solution is to go the old way of flushing oils to remove all old.
As another says a few RPM and products of engine working will stain the oil anyway.

 

[DavidJ]

I think DAKA's point is interesting, that it will take some time for the oil in the dip stick tube to be 'contaminated'...I wonder how long though?

 

[Refueler]

I would dispute that with my engine I know as the tube only enters crankcase a short distance. My dipstick is a steel thin bar - not flexi wire style so needs no support for last section inside case.
Therefore stick will show mixed oil.

Thinking further. If it was true then why does dipstick show significantly higher oil level after engine run even short period than if stopped on every car I've had ? Is it because oil being pumped round is forced up that short section of tube to falsely read ? A Question not Answer

 

[DAKA]

Im not arguing, just saying what I think......

Most of my engines and gear boxes show a reduced oil level on the dip immediately after the engine is switched off.

Once settled 30 mins the oil circulating round the engine/gearbox finds its way back to the sump and the dipstick level rises.

(The engine pressure will push oil up into the dip tube but this will settle in seconds once switched off.)

My gear box instructions specifically state the level needs to be dipped immediately after the gearbox is put in neutral or a dipstick reading will be falsely too high once the ATF has settled back in the sump.

Back to the dip tube, unfortunately model of engine was not specified.
many marine engines and some car engines are specifically designed to have dipstick tubes that can be used to drain oil so the tubes do get close to the bottom and do not dangle mid air like yours.

As to draining engine oil I believe my cummins-mercruiser has a pipe attached to the thread where a sump plug would normally fit , when I drain I get as much out as any vehicle engine on a ramp.

I further THINK that some volvo penta engines also have a pump tube to the sump so most old oil is taken out.