Diesel Oil Change Intervals?

[GQAndrew]

I know the general rule is that the oil should be changed every 5000 kms, but does this depend upon the type of driving that is done. For instance, my GQ SWB was a company car, that was used by the boss to drive to work and back each day, and occasionally tow a trailer and go out in the bush every now and then.
On the service record it shows that the oil changes were done every 10'000 kms. Now, is my engine not going to last as long because of this? Am I still likely to get 350'000kms+ out of it, and what is the best way I can check the engine condition? Compression Test?
I may start to spend some $$$ on the car in the near future, but want to know if the car is gonna be good for a few years. I will start changing the oil myself now every 5000, as I use the car off road every weekend.
I believe the engine is still in great condition, as it uses no oil, and am getting excellent fuel economy (11.5 - 12.7 L /100kms).
Thanks for any advice anyone can offer me on this.

Andrew

[Daisy]

To start doing the oil change every 5000kms as of now wouldnt hurt would it?

[GQAndrew]

To start doing the oil change every 5000kms as of now wouldnt hurt would it?

Nope, and I will do it, but am more worried about the prior changes. everyone stresses that diesel should be changed every 5000km, is 10000 changes really going to effect it that much?

I am in no way regretting buying the car, Diesel SWB's are extremely rare in Perth.

[r0ck_m0nkey]

If was my own personal vehicle i would be doing it every 5000km. But for an example, my previous company work ute was a 3.0L Diesel Hilux, and it would have been lucky to have even been serviced every 10 000km, and they got rid of it at 270 000km and it was still going good.

[duncan]

Its probably ok but do it from now on oil and filter every 5000ks fuel filter atleast once a year and keep the air filter clean shell run beautifully for you

[GQAndrew]

Its probably ok but do it from now on oil and filter every 5000ks fuel filter atleast once a year and keep the air filter clean shell run beautifully for you

will get a mechanic to give it a good check before I spend any major money on mods.

With oil changes, last time I used Penrite HRP Diesel 20W-60, some people say that with the premium oils it extends the change interval, so should I continue to use this oil and change every 10'000, or switch to a cheaper oil and do it every 5?

Can anyone recommend a good quality cheaper oil

[bazzle]

Castrol and the other major players recommend only ever using 15/40 on diesels.

There is a write as to why and the reason for 5000k changes on their site too.

Bazzle

[Leprecaun]

Castrol and the other major players recommend only ever using 15/40 on diesels.

There is a write as to why and the reason for 5000k changes on their site too.

Bazzle

Do you a link at all to this site ?

[Area54]

If it is running fine as you say - good economy, no oil usage, no smoke - I would start the oil changes cycle now at 5,000 and not worry about it. Even though they are a reliable motor, that's no excuse for abuse, but if you look after it from now it prolly hasn't harmed it in the long term. 10,000km of long running on the highway, at operating temperature, at optimum /peak power/efficiency band (approx 2200 RPM for TD42) will produce less soot and contaminants suspended in the oil than 5,000km around town/stop start/shopping trolley. Even though the oils do have lube components that 'self sacrifice' and are depleted over the life of the oil, quality oils and good combustion in an engine will keep the oil cleaner.

[GQAndrew]

How long does it normally take for the oil on the dipstick to go black?

[Area54]

never really taken much notice, prolly around 300-400 k's or so.Still a few ml's in the oil pump for priming, and a small amount in the sump with the drain plug not quite at the bottom.

[GQAndrew]

yeh, last time took about a week, its just that in a petrol, black oil is a sign that it needs changing, but Ive heard that with Diesel it will go black almost straight away

[Area54]

The diesel oil will soot up quicker, but if you have excessive black soot from the pipe on accelleration, you might want to get the injectors serviced, this is a 100,000 km job anyway, so if you don;t know when they were last done this is a good thing to do, keeps the fuel spray pattern at it's optimum, better atomisation and cleaner combustion, and cleaner oil to boot with less soot and particulates going into the oil from internal engine surfaces. But if the motor seems in relative good running order I wouldn't worry, just keep up to date with the overall servicing - oil + filters, injectors, fuel filters - and the motor will do exactly as the Nissan engineers intended. Basically an old skool truck motor, if serviced meticulously and driven accordingly, they'll last forever.

[Woop]

I think that with the TD42 being an older generation 'dirtier' running engine than the current range of cleaner diesels, 10,000km's is too much. Up until about 450,000km's i used Shell Rimula X 15W40 for each oil change at 5000km intervals. I had to change because Rimula X is a bit difficult to get out this side of town in 20l drums Both oil filters at 5000km's as well. It gets too cold down here in VIC to run a 20W in my opinion. I'll let you know when i pull down the rest of the engine for re-building shortly how worn everything is @550,000kms

Nick

[turps]

My oil goes black almost straight away. And the injectors do need doing. But I accept this on an engine with 450 000km and factory injectors. Saving for new injectors now though as I have had the car for 180 000km and I think they may need doing.

[bogged]

My oil goes black almost straight away. .

Yup, agree.

Look at Woops motor with 530,000klms onm it, oil and filters every 5000klms you can see the hone marks in the bore.. thats a good ad to treat your motor with respect in that regard.

No use worrying what has happened in the past, thats out of your control with the engine, treat it well as you own it wont do any harm at all.

YMWV

[GQAndrew]

It gets too cold down here in VIC to run a 20W in my opinion.

Im starting to think that I should use a 15W/40 next change, especially during winter, I think the Gregorys manual states that you should use a 20W/40, not sure about the Nissan Owners manual.

I think Penrite suggest the higher grade due to the age of the vehicle, with the GU 4.2, they suggest the lighter HPR 15

[Patroler]

This came from the 'hiflo website'

Fact Sheets
OIL THICKENING IN LIGHT WEIGHT DIESEL ENGINES
by LOU ACHTERBURG, CASTROL TECHNICAL SERVICES MANAGER


From time to time we encounter instances of excessive oil thickening in light weight diesel engines. While the factors which contribute to this condition are many and varied the obvious culprit in the minds of motorists is the oil itself, which is in reality the least likely cause of the condition.
High performance engine oils marketed by the major reputable oil companies have been developed to the point that in heavy duty diesel highway engines 40,000km service intervals are not unusual and the oil is still in reasonably good condition.

This exact same lubricant, usually an sae 15w/40 meeting at least api cf4/sg, can not go to 5,000km in a light diesel engine without significant thickening and deterioration.

OPERATING CONDITIONS ? WARM UP IS CRITICAL

The major difference in oil performance is due not only to differences in engine design but mostly due to operating condition. A diesel engine does not achieve combustion efficiency until it reaches operating temperature which usually takes 20 to 30 minutes of running. During this warm up period incomplete combustion deposits excessive quantities of carbon and soot on the cylinder walls where it is collected and absorbed by the dispersant additive in the oil. Frequent stop-start, short trips and periods of idling also increase the moisture contamination of the engine oil.

HOW IT HAPPENS

As most light weight diesels are not spectacular performers, most people tend to drive them hard through the gears, which leads to over fuelling and further contamination of the oil. The combustion by-products from a petrol engine are volatile and can be driven off once the engine is run at full operating temperature of a period of time.
However, the combustion by-products form a diesel engine cannot be driven off by engine temperature and as such are totally accumulative.

THE EFFECTS ON YOUR ENGINE

This build up of combustion residue eventually leads to the oil becoming very thick at cold start up so that it does not flow through the engine correctly and causes increased wear rates. The excessive moisture levels combine with the soot and carbon in the oil producing sludge deposits especially in the valve cover.

OTHER FACTORS TO CHECK

Other factors that contribute to oil thickening are:

Starting with a high viscosity oil - i.e. Sae m20w/50 should not be used.
Using an oil of lower performance level - i.e. Api sf/cd is totally unsuitable.
Engine running too cold due to faulty thermostat or even worse, no thermostat at all.
Faulty injectors or fuel pump set incorrectly

The way to head off these problems is to ensure a good quality brand name sae 15w/40 of at least api cf4/sg specification is used eg Castrol RX Super.
And the oil and filters are changed every 5,000km. 1/9/99
(A future fact sheet will explain oil specifications/classifications)


http://www.hiflo.com.au/mainframeset.html

[GQAndrew]

This came from the 'hiflo website'

Some very usefull info there.....cheers