I am using Shell Rotella 5w-40 T6 oil
- Thread starter carguy75
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Bingo. I knew that having oil leftover in the valve covers which is being flowed through the PCV system were a problem in the FX45's. I did not remove my valve covers to check, but since you have and acknowledged that your valve covers had a lot oil residue points to the strong possibility that the oil loss and start up smoke is from oil blowby that get past the pistons, then sucked into the PCV systems in the valve covers, and back into the combustion chamber through the air intake and burned off. The heavier 40 weight oil like the Shell T6 is probably thick enough not to easily slip by the loose piston rings that are in many first generation FX45s like the 5w-30 weight oil, and minimize the oily piston blowby that gets into the PCV system. Therefore, I believe you should try using the 5w-40 oil weight for a while and see if it helps you FX's smoking issue. I have noticed that the 5w-40 weight oil solved my FX's oil consumption problem, maybe it will help yours.
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Well... You are partly right except that you are going to have oil in the valve covers no matter what, its not from blowby, it flows there to lubricate the top end. Thats why I suspected valve seals, when not running the oil that is supposed to be there leaks past the seals into the cylinder.
At the same time, your understanding of the PCV system is right, and there is going to be some oil that also gets burned that way. My vacuum lines were oily inside when I replaced the PCV valves. A catch can is the best way to eliminate this as a possiblity. I havent got around to it yet.
With 55k on the motor I'm not ready to OD on trying to fix it. Too many people here have the same symptoms and never considered it a problem. My plugs are what really caught my attention. I will more than likey put a catch can on it to make sure thats not the problem. I have hesitated to use a heavier weight oil since the cam tensioner is hydraulic and if the oil flow is slowed down at start up some people end up getting the chain rattle. Ill probably just try to 40 weight next time and see it if changes anything if the catch can doesnt work.
As of now, there is very very little at start up and after seeing all the buildup on my plugs I am thinking its still possible it is burnoff from carbon or ash. I'm going to give it a couple weeks and see if anything changes. Im still curiious why the smoke is white with no hint of blue and doesnt smell like oil. Makes me think it is carbon or something.
Haha. True. I was thinking about the fact that valve covers normally have oil residue due to normal operation also after I posted that reply. I should have just mentioned that the poorly designed PCV system in the valve covers unfortunately sucks the oil that is present in the heads up into the intake system. I was thinking that oil from piston blow by was the major factor, but now I think that the oil loss in many FX45s is mostly just from oil in the heads that gets sucked into the air intake by the PCV system when the PCV valve is stuck open. Therefore, the faster a person drives the more air being sucked into the engine and hence more oil pulled through the PCV system in the valve covers. In addition, the burned oil could begin to cake the top of the pistons and help cause the rings to stick over time, which could mean more oil burning and eventually a smoking engine that drinks a lot of oil. I hope you just have carbon buildup in FX, if so you may have to open her up on a long open road and blow it out of the system. P.S. I have noticed the chain rattle when my FX is a couple quarts low, therefore I believe that the tensioner is oil pressure dependant and that the 40 weight oil will keep the oil pressure optimal, which is good for the oil pressure dependant systems like cam timing and tensioners.
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Thats what I was saying earlier in the post.... when I drove her at high speeds for long periods it burned up quite a bit of oil. I'm thinking it is the PCV system, especially after seeing how flat the valve covers are, the PCV inlets are so close to the cams I can imagine all kinds of oil making its way through there.
As far as the 5w 40 what I was saying is that at start up.. the thicker oil does not flow as rapidly causing low pressure on the cam tensioner not the other way around. Your oil pressure will be high at the oil pump but its going to take longer to make it up top. Its like blowing water through a straw vs blowing syrup through the straw. The pressure will be much higher blowing the syrup, but it will move much slower. I hesitated to bump up to 40 weight for this reason but I am rethinking that now as I see plenty of you guys do run it.
As far as the rings sticking... see http://www.infinitifx.org/viewtopic.php?f=2&t=25605
Not the buildup on the pistons, its the underside of the oil rings that begins to cause the problem. He was at 200k however and never used synthetic. Thats one of the main reasons I started with Mobil 1.
Oh and read this http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2341120
What these guys are saying makes sense. First off, Mobil 1 as most synthetics are a mix of different bases. There are pages and pages of explanation on that website but basically a full synthetic does not hold detergents and other additives well so the base is a mixture that includes some petroleum so that the other additives blend. End result is what matters most, not if the oil is a full synthetic or not.
Also what this guy said
"This isn't at all unlike Cadillac's Northstar engine. Driven conservatively, it'll start to smoke and consume oil (usually consume oil before any other symptom). The fix, if you can catch it in time, is the good ol' Italian tuneup. Later versions of the car had a different piston ring design, as the earlier engines were particularly prone to oil cake-up like what happened with that Infinity engine.
And if it's not already well-known, the Northstar was GM's first large-scale use (if I recall correctly) of their OLM, recommending as high as 12,500 miles on conventional oil.
It seems to be a classic case of engine mis-application really. Put a fairly high-performance engine (especially for its time), one that can and does thrive on high-load and high-speed operation, into a vehicle that typically sees conservative duty cycles and this is often the result."
and in addition Fords original 5.0 was another example of a motor that did this exact same thing. Lots of good info here.
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Good points. However, the weight of the oil could affect oil pressure through the whole system past the pump. A 5w-40 weight oil will not be thick enough to prevent proper oil flow in the engine, because Infiniti lists 10w-40 as acceptable in hot climate areas and the 5w-40 weight is a little thinner than 10w-40. However, i see your point about using too thick of an oil and how it could impede flow in the engine. The oil deposits on the top portion of the pistons could cause the rings to stick, especially when combined with carbon buildup. What do you think causes pistion rings to stick in any car with poor oil control over time? The oil and deposits that slip past the rings and collect on the piston rings themselves.
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FX45Chicago
Member
- Car
- 2005 FX45 AWD
I have to try this at my next oil change. Although, I haven't notice a lot of oil consumption. Which, could be due to the way I drive.
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---------- Post added at 06:48 AM ---------- Previous post was at 06:41 AM ----------
Before, doing this I wonder if it would be recommended to seaform before the switch over? 500-1000miles before next oil change.
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Sent from my iPhone
---------- Post added at 06:48 AM ---------- Previous post was at 06:41 AM ----------
Before, doing this I wonder if it would be recommended to seaform before the switch over? 500-1000miles before next oil change.
Sent from my iPhone
I used Seaform before, but I do not know if it helped at all. However,you do not need to use it before changing to a new type of oil.
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Update. I finally changed my oil this weekend, and have noticed that I drained nearly the same amount as I initially put in. However, I did lose about a half of quart of oil during my 4k oil change interval, which is good in the summer for me, because I usually lose about 1 to 1 1/2 quarts in the summer when I used 5w-30. I still drove my FX hard, so I believe that I will always lose some oil due to the poorly designed PCV system in the pre-06 FX45s. But I can live with losing up to a quart of oil between oil changes in the summer. So, I will be using the Shell T6 oil for now on. FYI for those who care.
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payyourtoll
Member
- Name
- Rob
I also switch to Shell Rotella T6 5W-40 a couple of days ago on my 03 FX45. I have been using Mobil 1 5W-30 and refilled with up to a 1.5 quart on a 7500 miles oil change interval.
I noticed T6 is available like shown here for diesel engines, and then another T6 for gas engines. I just bought the diesel type and wondering if that is wrong?
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payyourtoll
Member
- Name
- Rob
Okay I just called Shell and spoke to the Rotella department. At first they were not sure of my question regarding the two different types of the 5W 40 but then Were able to confirm that there is only one type of this T6 oil. They explain ed to me how it can be used in both diesel and gas engines with no problem. Even though some bottles may not say heavy-duty diesel on the actual sticker, there is only one type of T6 so we are good to go
---------- Post added at 07:22 AM ---------- Previous post was at 07:18 AM ----------
This was the non-diesel label I saw
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Okay I just called Shell and spoke to the Rotella department. At first they were not sure of my question regarding the two different types of the 5W 40 but then Were able to confirm that there is only one type of this T6 oil. They explain ed to me how it can be used in both diesel and gas engines with no problem. Even though some bottles may not say heavy-duty diesel on the actual sticker, there is only one type of T6 so we are good to go
---------- Post added at 07:22 AM ---------- Previous post was at 07:18 AM ----------
This was the non-diesel label I saw
Do not feel bad about the misunderstanding with the T6 oil classification. I first thought it was a diesel only oil also until I did extensive research on the T6, however it does carries a certification for use in both regular engines and diesel engines. I believe most 5w-40 diesel oils now covers both certifications.
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payyourtoll
Member
- Name
- Rob
lol me too brother
Did you get them for a good price? Oreilly's used to sell T6 for $20 a 4 quart bottle, now the price is $22 for the same amount.