As I recently purchased an 02 Q45 with 47k, a thread in the Q45 section has peaked my interest. In it, the owner of an 06 Q45 was bemoaning excessive oil consumption for this engine. Later I found this was a common complaint.

I bought my vehicle after verifying it was a one owner and was serviced by Infiniti since new.

Oil consumption occurs either by leakage to the external environment or into the conbustion process. The latter occurs usually passing the piston rings or the valve guides.

From Infiniti's response in that thread, it would appear that the piston rings were the culprit. Specifically, the oil wiper ring. Before reading this thread I would have suspected the valve guides since the engine was the first with titanium valves.

I have noticed that break-in intervals (as noted by mileage improvement) on my Fords have been extending over the last 20 years. In fact my 2008 Mustang took over 25K before it finally seated in. This extended break-in seems to have occurred with Ford's switch to semi-synthetic oil. I've monitored this because I refuse to use full synthetic oil before the rings finally seat.

My son is a BMW believer and often bragged about BMW using only synthetic oil. This leads me to wonder if the F50 problem is a break-in/oil problem or a design problem?

I would find it hard to believe that Nissan would suddenly forget how to prep a cylinder bore for break-in. If a material or design change in the wiper ring were the cause, I would assume this problem would have been identified and eliminated over time. A new engine design may be subject to cylinder scoring/piston slap, but again this is the kind of problem that Japanese "continuous improvement methods" would have caught and resolved. If there was a serious wear problem on the cylinder wall, I would assume it would be easily visible with a bore scope. Thus, I would expect experienced mechanics would have made this widely known by now.

Does anyone know what the initial oil used in these engines was? And was there any specific recommendations on the use of full synthetic oils? I would assume that most early maintenance was performed by the dealerships. Was there any guidance from Infiniti to the dealers regarding oils?

Does anyone in this group know the specific cause of high oil consumption in these engines?

The car I purchased had no signs of oil burning in the exhaust. Other than monitoring oil levels, is there anything else I should look out for?

Usually too light ring tension to boost power [lower friction]. Some rings flutter and back off tension in high vacuum situation [deceleration].

All attempts to improve mpg and increase power output from same displacement engines.

It is the rings and it isn't the bore. This happened on the VK, VQ, and QR all around that time frame due to a switch to a cheaper ring manufacturer.

what xjared said or if it has had a catalyst failure and sucked up cat material into the cylinders!

Noone knows for sure what cause the burning. I had 140k miles on my VK45DE and it still running strong. I checked the tail pipe every time when first start up and if I do see the smoke then I just change the oil it will go away. There isnt much u can do on the issues. U just have to watch the oil level and pay extra attention to the engine. VK45DE is an high HP race spec engine that pump out alot HP so Its not unusual for that to burn some oils. It happen to all MB/BMW engine as well so its not something just INFINTI's engine problems. I guess the modem high HP engines dose have this issues that owners need to deal or live with.

Y34GLORIA wrote:Noone knows for sure what cause the burning. I had 140k miles on my VK45DE and it still running strong. I checked the tail pipe every time when first start up and if I do see the smoke then I just change the oil it will go away. There isnt much u can do on the issues. U just have to watch the oil level and pay extra attention to the engine. VK45DE is an high HP race spec engine that pump out alot HP so Its not unusual for that to burn some oils. It happen to all MB/BMW engine as well so its not something just INFINTI's engine problems. I guess the modem high HP engines dose have this issues that owners need to deal or live with.

I'm gonna say this and probably have it backfire on me but here it goes....

My vk45de 2006 M45 is probably the most modified VK45DE in existence on the internets. Raised redline to 7200rpm and pulls nearly the whole way there. 306rwhp and a little more torque.....run the hell out of it most of the time, but I do baby it and decel when possible for fuel economy.

Only oil my engine has used is the oil it has collected in the Catch can for the PCV system I made. And in about 20,000mi that's about 6-8ounces. Running Amsoil HDD 5-30 oil with extended OCI so far it's been 10K mi on this oil and will be sampling the oil and sending it into the lab for analysis.

My theory is the PCV system dumps oil into the intake which progressivly causes the oil consumption issue to get worse and worse over time and causes the rings to stick letting the oil by.

I don't think any engine should suck down a quart of oil in 3k mi - something seriously wrong there.

Oh - btw I have 69K mi on my engine.

Your point interests me, Ken. I owned an airplane with a Lycoming O-360, 180 HP engine. Oil consumption in the range of 1 qt per hr was not considered excessive. Therefore the engine had a huge sump.

If you filled the oil to the recommended level on the dipstick, for sure it would be down a quart the next time you landed. If you left it a quart low, the oil consumption would drop 3-6 oz per hour.

We finally found out the oil was being flung out of the breather vent due to excessive agitation of the crank turning through sump. Some bright fellow eventually came up with a device to re-capture this oil and return it to the engine.

Could you describe your PCV device a little more detail?

djwarner wrote:As I recently purchased an 02 Q45 with 47k, a thread in the Q45 section has peaked my interest.

I think you mean piqued, not the nonexistent past tense of the noun "peak."

It's essentially the same thing for aircraft except the aircraft version is engineered to death with internal vortex generation to utilize centifugal force to help sling the oil out of the air to help in capturing the oild.

Mine i made from a stainless steel waterbottle I bought for $6.

I don't have any "good" pics but on a modern auto engine the PCV system has a hose going to both sides of the throttle plate. One sees vacuum and the other atmo. this allows the crankcase to breathe without polluting the air with vaporized engine oil and other crankcase contaminants including unburnt HCs and CO2 etc, etc... It is a closed system that was invented so that the EAQB and EPA could be happy alongside Mrs Smith driving home stopped at a stoplight smelling stinky engine fumes. The closed PCV system solves both problems well under normal driving situations.

Where it fails is in High load situations where the engine oil will vaporize and gets forced through the vacuum side of the system where it is allowed to condense back into liquid once it hits the "cooler" intake manifold. this is where the deposits land and eventually end up inside the combustion chambers. The oil burns about as nicely as diesel and lower effective aki of available gasoline lowering performance. Also burning like diesel is that it leads to carbon deposits on the valves and inside the combustion chambers as well as the piston and rings.

If you google PCV catch can mine closely resembles this one. It is installed on the Low Pressure(vacuum) side of the system and is simply installed inline with the original line much as you would install a fuel filter. It has an in/out that needs to be used correctly. direction of the linse should be in this order from the engine, to the top of the bottle(catch can), out the side of the bottle(catch can), and to the port on the intake manifold that is behind the throttle plate.

Special care should also be taken when inspecting the PCV Valve to verify it's operation and it is functioning correctly.

I like this unit because of it's size - bigger is better with stainless steel wool filter media in my opinion because it can more accurately imitate the intake manifold allowing expansion/ temperature drop/ and surface area to aid in condensation of the liquid and enough surface area to collect it. A side benefit to a larger PCV Catch Can is that makes for longer service intervals/draining. Mine is 32oz so I could probably go 50k-70k mi between servicing.

Each brand and viscosity of oil has its own volitility index which can be extrapolated into how much will evaporate in how many miles.

If a 6 quart sump evaporates 5% that 0.3 quarts [11 ounces] of lighter fractions. Most oil run 6-12% in ASTM D-5800 Test.

so not really trying to start anything, but me and xjared are both certified nissan tech's and it seems that noone is believing what we've said. our statements have been proven by nissan and the information given out to all of the dealers and tech's that go to training centers. just throttles me that people make up farse dreams and assumptions of what they really think is wrong with their cars! listen to the factory trained guys and throw your assumptions in the garbage!

Not discounting your input at all.

My engine is not burning that much oil. I only asked to know what to look out for.

I know I and many others appreciate your first hand input.

Sometimes root causes remain hidden for sometime. The particular version of Lycomming engine I owned was known for eating valves due to poor lubrication of the valve guides. Coke would build up between the valve stem and guide until the valve would stick open and contact the piston.

Since other configurations of the same engine were not experiencing this problem, speculation and theories abounded. Finally, an engine overhauler noticed the oil pressure sensor was positioned at the inlet side of the oil galley where other versions had the sensor at the far end of the galley. These engines had an adjustable oil pressure regulator and had to be set at a specific pressure per Lycomming specs. Unfortunately, the original specs were established with the sensor at the far end of the galley. When they re-positioned it on this model, there was a significant drop in oil pressure at the valve guides.

With FAA regulations, mechanics were not allowed to move the pressure sensor without a change order from Lycomming, who, fearing lawsuits, refused to admit there was a design problem.

Wise mechanics ended up adding a supplemental pressure gage and unofficially set the pressure regulator from that gage. This worked very well until you visited a strange mechanic who would reset it.

right on man well i wish you the best! g/l w/the vk45 seems like a good engine to me with the exception of the issues me and xjared described!

newbissan-tech wrote:so not really trying to start anything, but me and xjared are both certified nissan tech's and it seems that noone is believing what we've said. our statements have been proven by nissan and the information given out to all of the dealers and tech's that go to training centers. just throttles me that people make up farse dreams and assumptions of what they really think is wrong with their cars! listen to the factory trained guys and throw your assumptions in the garbage!

lol - You mean "farce" I think. Oh and you say Nissan has published this information about low tention piston rings? What years were affected? To my knowledge the oil consumption issue has been an issue on the VK45DE engine from 2002 till 2007 - so for 5 years nissan never did anything concerning this issue?

The catalyst failure is common and with the reversion function of the low rpm cam overlap to act as an egr valve can suck up some catalyst chuncks if they break off within the engine side of the manifold. I have my factory manifolds removes in lieu of headers and have confirmed that mine were still in one piece.

Oh and one last thing - I too have been a factory trained nissan tech, Have 2 degrees, ASE Certified, PA Inspection Certified, and I stayed in a Holiday Inn Express last night. Does that increase my credibility for my "Farse" dreams - lol

Welcome to my world where your opinion means squat till you provide a little more proof other than "I'm a tech and know all" - not trying to start something though

i don't doubt your credibility a all, but do you,... "a certified nissan tech" just like me doubt the facts that nissan has stated for years that they chose crappy rings and that cam overlap working as an egr sucking in cat material is also an issue that can contribute to premature ring wear? also i have replaced dozens of cats that were intact and had no physical damage and within months the motor went south and started smoking! it doesn't take but the smallest particulate or dust to wreak havoc on rings and cylinders. i don't at all doubt what you're saying just stating the facts and experiences that i have personally had with the issues that are involved with this post. no disrespect was meant but yes i meant farce .

and nissan has produced the information, but nothing publicly only to tech's and training centers! there might even be a tsb but can't for sure verify that without looking it up in assist at work. but anywho my .02 cents! no disrespect!

newbissan-tech wrote:and nissan has produced the information, but nothing publicly only to tech's and training centers! there might even be a tsb but can't for sure verify that without looking it up in assist at work. but anywho my .02 cents! no disrespect!

I was just givin ya a hard time, and I absoloutely agree about the rings. They are junk and deserve the heat from 10,000 suns in hell for installing those little b's. But they themselves - all things being equal with no FOD - will be fine 90% of the time. I feel that it's the oil contaminant that is mostly to blame because of the effect that it has not only on the rings, but on the combustion cycle all together. Oil promotes octane degridation of the air/fuel mixtrure leading to detonation and also to increased carbon deposits that can promote pre-ignition and detonation due to hot spots inside the combustion chamber. The detonation is a main cause of ring failure and also one of the contributing factors of catalyst destruction. The pre-ignition can also crack pistons in extreme circumstances from which I have seen happen to 2 cases alone on this board.

Unfortunately, you know as well as I do, that it is cheaper for Nissan to replace than to R&R an engine. So we, as tech's, diagnose the issue as either an oil consuption issue or a bottom end engine knock and proceed to wait for the new long block assembly to show up to pull the old and install the new without actually identifying the real issue. Not saying that is a bad thing either so don't get me wrong.

Also as a Tech and outside the tech's life in my desk job I have learned that sometimes a press release is just what everyone wants to hear because the real reason no one would understand. Grain of salt/half truth type of stuff. Not baggin on anyone either.

And like I said - this could majorly backfire on me too - watch tomorrow I have a terrible bottom end knock right as I click over 70K mi is there a knock on wood smiley? - lol

I have an 03 FX45 and have suffered from the oil consumption for about 3 years now.

At 35,000 I had dealer inspect motor for valve ticking on startupAt 59,000 I noticed oil consumption and asked for consumption test (Didnt make it back to dealer for end of test.. 1000 mile check)At 66,000 I returned to dealer with oil consumption concern and began noticing white smoke on startup, especially if it sat for the weekend)At 67,000 I again asked for the oil consumption test but I again failed to return to the dealer in time to get 1000 mile result.

Each time I was told that I just needed to add a fuel system cleaner and that the smoke was only morning condensation. I knew there was more to it and I knew it wasnt condensation.

Now at 89,000 miles I have 2800 miles on the current oil and have had to add 2 quarts so far. I still have the white smoke on morning startups but other than that and oil consumption it still runs strong.

I was gonna attempt to change the valve guides but after reading this post that may not be the issue. Sounds like we just live with the problem.

Not to bring this back to topic 5 months later, so if I were to rebuild the bottom end, which ring brand would you suggest I buy? Obviously, not Nissan?

if npr offers a ring set for the VK45DE then go with them, they are the oem ring manufacturer for nissan from the dark ages...presumably before they swapped to a cheaper ring.

newbissan-tech wrote:and nissan has produced the information, but nothing publicly only to tech's and training centers! there might even be a tsb but can't for sure verify that without looking it up in assist at work. but anywho my .02 cents! no disrespect!

I registered on NICO just to PM someone and it won't even let me do it cuz I'm new! Lol

I'm having some M45 oil issues myself and was wondering if you could e-mail me those documents you mention about Nissan knowing about the piston ring problems and what symptoms it would develop. You would save me a lot of money and help me out a lot!!!

Thanks!!! Please put something obvious in the subject line so I recognize it in my junk folder.


Dave
[email protected]