Can changing oil types cause oil consumption?

[Dougal]

Quick but possibly complex question. Can a change of oil type cause smoking and oil consumption?

My 4BD1T (35k on rebuild with aftermarket pistons and liners) appears to be burning 2-3 litres of oil per 1000km and is smoking a little blue at idle.
There are two recent changes of note.
1. Fitted a provent about 1300km ago, so I know the oil isn't coming from the intake and the 1" hoses mean the crankcase isn't pressurising under hard use.
2. Changed to Agip oil just under 3,000km ago. I was using Shell Rimula X. Both 15w40.

Now it could be that I've cooked my aftermarket pistons (they have seen 900C on the pyro occasionally). But I'd like to check all options before stripping it down.
The engine starts fine and performance is good. But it's smoking blue/grey at idle and it's also smoking black under load where it didn't used to.

[kentkal]

I have experienced that with a >>> 1HZ>>>, change of oil brand and exessive useage, change back to original brand and nil usage. Strange :confused:

[Dougal]

I have experienced that with a >>> 1HZ>>>, change of oil brand and exessive useage, change back to original brand and nil usage. Strange :confused:

Has anyone stuck with the new oil until it came right?

[Blknight.aus]

yes, a change in oil can cause engines to smoke, without diving into the tech details if the new oil doesnt skin as well as the old oil then it can work its ways pass the rings and theres your smoke.

The bad news is its a sign of a worn engine and just occsionally once it starts be cause of the carbon left behind by the initial burning oil the rings can stick and that means its time for a pull down.

[Dougal]

I'll do a pull down if needed. Fit genuine Isuzu pistons and liners in place of the generic items in there right now. Current items are 35,000km old (if not melted/cracked then just barely run in).

In the next two weeks I have 1500km of driving to be done. Do I take two oil bottles just in case?

[steveG]

If you're going to have to buy a couple of containers of oil anyway for it to consume, why don't you drop whats currently in it into a clean container, then fill with the previous type of oil you were using.
If the consumption/smoking stops you're on a winner, otherwise you just use the removed oil to top up with.

Steve

[Dougal]

If you're going to have to buy a couple of containers of oil anyway for it to consume, why don't you drop whats currently in it into a clean container, then fill with the previous type of oil you were using.
If the consumption/smoking stops you're on a winner, otherwise you just use the removed oil to top up with.

Steve

Due to a better purchasing arrangement (20L buckets), the new oil is roughly half the price of the old, I intend to stay with the new oil. The question is "will it bed back in or will I get sick of it and throw in new pistons/rings/liners?"

Going back to the old oil would likely just prolong the agony. 2-3 litres per 1000km is nothing compared to say a galant, but it's 2-3 litres more than I'd like it to use.

[Hoges]

I'd try a 20w-50w and see if that improves things. It maybe a simple bedding in issue.

Another thought: when you refurbed the block, did you give the head any attention? I'm thinking valve stem seals...
good luck

[rick130]

It can happen Dougal.

Which Agip oil ?

IIRC most Japanese diesel engine manufacturers from the mid eighties on called for >3000ppm calcium (calcium carbonate ?) in the add pack for detergency/solvency and also, to a lesser degree, EP protection for the cam.

Not many oils carry that sort of excessive/overbased calcium these days as ;

1) it can lead to carbon (ash) buildup in the chamber
2) AW and EP protection can be gained by using combinations of other organo-metallic and non-metallic additives.


I just read through some papers that a tribologist I have a lot of time for has published online, and in a Q and A part someone asked the question about additive packs and oil consumption.

In his opinion it shouldn't make much difference, but what can happen (and I've experienced this) is that the base oil viscosity and viscosity index improver used can make a huge difference to oil consumption.

In a nutshell, a relatively lighter weight base oil with lots of VII's to meet a certain viscosity range will volatilise more easily and lead to increased oil consumption.

The only way to know for sure before buying is to compare NOACK numbers of an oil, but these are rarely published.
The oil I'm currently running (10W-40) had a very low NOACK % of 9.5% in it's first published TDS, but subsequent revised TDS's don't show the NOACK number.
A lot of multigrade oils are up near 20% NOACK.

[LandyAndy]

Any chance you have glazed it up by being too kind????
Get a HEAVY trailer and punish it on some big hills,see if it improves.
GOODLUCK
Andrew

[Hoges]

Any chance you have glazed it up by being too kind????
Get a HEAVY trailer and punish it on some big hills,see if it improves.
GOODLUCK
Andrew

Excellent point. I had a VX LS1 which the local GMH dealer's Service Manager, ever willing to wring a few extra $$$ from a service suddenly changed the oil one day to Mobil 1 (@ 15000km). From then on the car drank about 1.5L per 1000km (to the cries of "It's normal"). Stamped foot one day a year later at atrocious oil consumption and "new" service manager blamed ME for switching to Mobil 1:twisted: They refilled it with a 10-40 (instead of 0w-30w) and told me to take it for a decent "thrash"... which I did by driving a lot in 2nd and 3rd in cruise control at 105kmh on Bris-Sydney trip. On the return journey cruising in top gear (4th) the oil consumption had dropped to 0.5L in 2000km. My son now has the car... he reports about 500ml in 5000km... (120,000km) (Magnatec 10w-40w)...

[Dougal]

It can happen Dougal.

Which Agip oil ?

IIRC most Japanese diesel engine manufacturers from the mid eighties on called for >3000ppm calcium (calcium carbonate ?) in the add pack for detergency/solvency and also, to a lesser degree, EP protection for the cam.

Not many oils carry that sort of excessive/overbased calcium these days as ;

1) it can lead to carbon (ash) buildup in the chamber
2) AW and EP protection can be gained by using combinations of other organo-metallic and non-metallic additives.


I just read through some papers that a tribologist I have a lot of time for has published online, and in a Q and A part someone asked the question about additive packs and oil consumption.

In his opinion it shouldn't make much difference, but what can happen (and I've experienced this) is that the base oil viscosity and viscosity index improver used can make a huge difference to oil consumption.

In a nutshell, a relatively lighter weight base oil with lots of VII's to meet a certain viscosity range will volatilise more easily and lead to increased oil consumption.

The only way to know for sure before buying is to compare NOACK numbers of an oil, but these are rarely published.
The oil I'm currently running (10W-40) had a very low NOACK % of 9.5% in it's first published TDS, but subsequent revised TDS's don't show the NOACK number.
A lot of multigrade oils are up near 20% NOACK.

This is the oil. Agip superturbodiesel 15w40.
http://transdiesel.com/download.aspx?id=556b78c9-d3bb-467f-bcea-01b3a633adb9

This is what I was using:
Shell Rimula X 15w40:
http://www.epc.shell.com/Docs/GPCDOC_X_cbe_24855_key_140002237494_1D70.pdf


Any chance you have glazed it up by being too kind????
Get a HEAVY trailer and punish it on some big hills,see if it improves.
GOODLUCK
Andrew

Hi Andy. No risk at all of that. The opposite actually, if it's not the oil then I may have melted or cracked a piston.
There were two decent towing tests in that last 1300km. Sustained 750C EGT's, even snuck higher when the revs got too low.

The head was done at the last rebuild. Valve guides and seals replaced and valves reground. The worn valve guides and the amount of oil they dropped were the main reason for the last rebuild.

[uninformed]

Dougal, Dougal, Dougal......you had to go and install one of those heavy, unreliable, underpowerd, fuel hungry Isuzu's.....much against all the advice that told you that the best diesel engines for any rover are either the world beating 2.5TD (pre TDI) or the bulletproof 2.4VM......shame on you :p

[rick130]

On paper, the Agip brew is a better oil, (the ACEA specs the Shell oil meets are obsolete and the API ones are pretty much obsolete too) so :confused:

[Blknight.aus]

Dougal, Dougal, Dougal......you had to go and install one of those heavy, unreliable, underpowerd, fuel hungry Isuzu's.....much against all the advice that told you that the best diesel engines for any rover are either the world beating 2.5TD (pre TDI) or the bulletproof 2.4VM......shame on you :p

and now I understand the origin of your profile name.

[Dougal]

Dougal, Dougal, Dougal......you had to go and install one of those heavy, unreliable, underpowerd, fuel hungry Isuzu's.....much against all the advice that told you that the best diesel engines for any rover are either the world beating 2.5TD (pre TDI) or the bulletproof 2.4VM......shame on you :p

Surely all my problems are the result of never using low range on those uphill towing starts.:angel:

[Blknight.aus]

Surely all my problems are the result of never using low range on those uphill towing starts.:angel:

wait, The Isuzus have low range?

[Sprint]

wait, The Isuzus have low range?

apparently its fitted just in case someone ever needs to change the rotation of the earth......

[Dougal]

wait, The Isuzus have low range?

Apparently so and needed so infrequently that I only noticed earlier this year that in low range unlocked the TC lever hits the gearlever in 3 and 5.:D

[wrinklearthur]

Hi All

Which model Isuzu truck's do you find the equivalent engines that suit the Land Rover?

Oh yeah, what oil do the trucks use? :angel:

.

[Dougal]

Hi All

Which model Isuzu truck's do you find the equivalent engines that suit the Land Rover?

Oh yeah, what oil do the trucks use? :angel:

.

Depending on the market, 1986 to 1994 Isuzu NPR's. They use exactly the same oil.

[Dougal]

After an interesting experience today, I think it's my turbo. Looks like I won't be taking the rover on the Christmas and New Years jaunts.

Think slow 90 deg corner, accelerate out and notice a big cloud of black behind me. Lift off and the EGT gauge stays pinned at 750C with the boost gauge sitting on 3psi. Clutch in and engine sits at about 2500rpm sounding awful while feeding on it's own oil. Luckily it only last a few seconds, but felt like a lot longer.

It did exactly the same thing on a similar left hander 10km later. My theory is the turbo has worn bearings and seals which are bleeding oil into the intake piping, the left handers are dislodging it where it's running into the manifold and fumigating the road ways.

This turbo bearings and seals were dubious when I built and fitted it. One of those short term experiments that turned out to be a long term fitment. A rebuild is no problem, but it'll be well into the new year before I can get a T25 rebuild kit.

[Dougal]

Bit of an update with no good news.

Over the past few weeks I have rebuilt the turbo at midnight, rebuilt the turbo a second time at a more reasonable hour remembering to install the compressor side seal ring. Remachined the turbo compressor housing (different tolerances on the new thrust bearings) and still no improvement in smoke or oil consumption. Turbo drains are all large and clear right through the engine block. I even tried a restrictor in the turbo oil feed. No change. Oil consumption hit an all time high of around 1 litre per 20km the other night. I was pushing it hard to test though.

Today I unbolted the turbo and went for a run. Underbonnet inspection afterwards shows the vent hose from the provent is spraying a decent quantity of oil around, the provent itself is flooded with oil. This explains the oil in the vent tube. Normally this vent tube is feeding the turbo intake, hence the suspicion of the turbo.

In summary, the turbo is an innocent victim. I'll wait to hear from Ben about the provent and possible mitigation there (i.e. bigger drain, possibly raise the drain to above oil level). I'll also start saving for genuine piston/liner/ring kits.

In the mean-time I'll just back off the power a lot so it can do the short range offroad work without chewing too much of it's own oil.

[Dougal]

Solved. It was the provent and here is what I did to fix it.

http://www.aulro.com/afvb/showthread.php?p=1622856#post1622842

With the benefit of hindsight, the oil consumption started early december and that was when I fitted the provent. I noted in mid december that I had to add 2-3 litres of oil and the engine was very smokey. The original vent hose from the provent went uphill and thus gravity drained a lot of it back.

The oil consumption hit a peak when I re-routed that hose to be more level. At this point the vehicle was literally a smoke machine. It created banks of bad smelling fog.

[isuzurover]

As mentioned in the other thread, you must have serious amounts of blowby/oil.

The PV200 is ftted to engines up to 200 kW. Most heavy diesels are known for having high rates of blowby.

I once had some issues running Penrite Japan truck 25, which is significantly more viscous than Castrol RX Super that I normally run. The front main seal was on the way out, and slight increase in crankcase pressure was causing oil to push out past the front main seal. I pulled the provent element, which stopped the oil leak, allowing me to drive the ~2500 km home to replace the seal and change back to RX Super!

[Dougal]

I don't have a way of easily measuring the exact amount of blowby, but it isn't extreme.
Last rebuild was approx 35,000km ago, ring gaps were IIRC 17 thou, which is on the high side of factory spec (10-18 thou), but still in spec.

This engine has always breathed a lot, but not excessively. The previous setup had a 12mm restriction which under sustained high load and rpm caused the crank case to pressurise and the rear crank seal to leak, but was okay if you weren't heavy towing or chasing sports cars up hills.
With the provent and 1" lines (down to 16mm OD barbs either end) the crankcase pressure is too low to register on a basic pressure gauge (i.e. not even 1psi).
It flowed well, there were just two problems. Not seperating oil and letting go of it in big gloops on certain inclinations. An engine running on it's own oil is a terrible sound.

The provent may have worked fine with the stock setup if it could be mounted half a metre higher to help it drain. But I can't do that.

[Dougal]

Just another thought. The provent might be intended for up to 200kw diesels with internal oil seperators still fitted.
The 4BD1T has a factory external air/oil seperator which the provent has replaced. It's going to take more oil on this engine than any other of comparable output.

[isuzurover]

Just another thought. The provent might be intended for up to 200kw diesels with internal oil seperators still fitted.
The 4BD1T has a factory external air/oil seperator which the provent has replaced. It's going to take more oil on this engine than any other of comparable output.

No, it is intended/used as a stand-alone unit. Btw, the factory 4BD1T rocker covers (which I also have fitted) use inertial oil separation before the gas leaves the rocker cover.

[Dougal]

Do you have a long hump or short hump rocker cover?
I couldn't get the screws undone on the breather cover between the inner rocker cover and the outer the acoustic cover. So I left it alone. I have the short hump cover (pre 1988) and I suspect whatever in there that was supposed to seperate oil, no longer works.

Under the inner rocker cover mine just picks up at the rear and travels along a bit to meet the tube.

[Dougal]

There is one big reason the 4BD1T's have oil seperators and the 4BD1's don't. It's the oil squirters under the pistons. These create a huge amount of oil mist which is carried out the breather.

The non turbo motors don't have the piston squirters and hence don't have (don't need) a factory external air/oil seperator either.

[rick130]

There is one big reason the 4BD1T's have oil seperators and the 4BD1's don't. It's the oil squirters under the pistons. These create a huge amount of oil mist which is carried out the breather.

The non turbo motors don't have the piston squirters and hence don't have (don't need) a factory external air/oil seperator either.

That would explain the oil carryover in Tdi's too. (or any TD with piston oil cooling)

[isuzurover]

There is one big reason the 4BD1T's have oil seperators and the 4BD1's don't. It's the oil squirters under the pistons. These create a huge amount of oil mist which is carried out the breather.

The non turbo motors don't have the piston squirters and hence don't have (don't need) a factory external air/oil seperator either.

4BD1s do have a (crude) separator. IME even turbo diesels without piston cooling produce a healthy amount of oil mist.