2001 Infiniti QX4, 151k. Burning oil like crazy!

Joined
Aug 14, 2014
Messages
20
Location
Denver
I've actually been dealing with this problem since I bought the truck in 2014 at 125k. I should have known better when the car was 1 quart low during the test drive. Anyway, I was unsure of the history of the truck and consistently have been using 5w30 High Mileage Mobile 1 since I bought it. The truck has been burning a quart every 1000-1500 miles which is driving me crazy! Sometimes I forget to check it and it is close to 1.5 quarts low! Never had any oil lights and it always starts up (have been dealing with a loud timing chain rattle since purchase though). For the first time since purchase, I switched to 10w30 Mobile 1 High Mileage when I changed the oil today; I'm beginning to wonder if I should give up with the Mobil 1 synthetic and go with conventional. I've been trying to be patient, but there is obviously some issue going on with my truck; I feel like I have to check the oil every time I drive it!

Any ideas? Thank you!
 
If the reason you're wanting to change back to running a conventional rather than synthetic is because you are wanting to save money, I agree and think you should. Also, burning a quart every 1,000 miles may soon lead to catalyst failure, so you might want to have someone look at your catalytic converter for signs of clogging. (It might be a good idea to actually do a cat-delete, but keep your muffler in case cops in your area are the kind to actually care about that kind of thing - mind you this is a last resort option).

My advice would be:
1. check your PCV (if you have one)
2. run a compression test (if you can find the resources to do it)
3. check your spark plugs for signs of gunk that could lead to possible fouling
4. stock up on dirt cheap (but API certified) oil for top ups
5. run 2 fuel system cleaners through your gas, one being any additive with PEA, and the other being Berryman B12
 
I changed the PCV valve and spark plugs last year and don't recall anything that jumped out at me. I will run the fuel cleaners and report back. If I were to switch to conventional, is it reasonable to expect any improvement on consumption? Not sure if anyone has any positive results just by switching.

Thanks,
 
Looks like you have the first iteration of the famous Nissan VQ35DE motor. Do the PCV valve again, and how about some Valvoline Maxlife motor oil next time? Good luck! Let us know.
 
The PCV vale was pain to get to. I had to remove the upper intake manifold which requires a replacement gasket! :-/ . any additives that could help? Any recommended oil viscosity? My truck's manual recommends 5w30. Thank you
 
Originally Posted By: Legend11
The PCV vale was pain to get to. I had to remove the upper intake manifold which requires a replacement gasket! :-/ . any additives that could help? Any recommended oil viscosity? My truck's manual recommends 5w30. Thank you

Factory viscosity 5w30 is what you should start with, my good man. Do you have any easy way of accessing one end of the hose that the PCV connects to? You could spray fog in some degreaser to unstick the valve if its stuck.
 
I have seen some posts on here where engines burn Mobil 1 like crazy, and burned a lot less with other oils. If Plan A is not working for you, switch to Plan B; I agree with the strategy of changing to a different oil and Valvoline Maxlife is a good choice. I also agree with moving up in viscosity to 10W-30 or perhaps even a 10w40.

Or more simply - while you're waiting for your gas tank to fill open the hood, check oil, top off. It's not that hard.
 
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Hey Kuato, 10W30 moving up in viscosity? It's still in the 30 grade region. Some 5W30 A3/B4 euro oils will also be thicker than any 10W30 "resource conserving" oils.

I'd go with a higher viscosity. It's not going to hurt anything as the oil is getting used up somehow anyways. If in hot weather, go with very cheap 15W40 or 10W40. If you need some cold start performance, 5W40. If you live in super freezing conditions, 0W40. Either way, I'd ditch the 5W30 as most are "resource conserving" ie; the thin side of 30 grade. See if it helps at all.

Compression test is a good idea but it can still have good compression and have oil leaking past.
 
Yes, Gumout Regane High Mileage or Chevron Techron at Walmart for around $5. The B12 Chemtool also at WM for $4. Both of those prices include tax, so that's the out the door price.
smile.gif
 
I've always heard great things about Mobile 1 and it's probably the only reason I've stuck with it. I have not heard anything about Valvoline MaxLife 5w30; is there something unique about that oil that will help over the Mobile 1 I'm currently using? I will give it a try next change.

I will also pickup some fuel cleaner (b12 chemtool, gumout regane high mileage, or chevron techron). How does the Lucas fuel cleaner rank with these? I believe I have a bottle in the garage. Just curious what the fuel cleaner does to prevent the oil from burning.

Also, I've primarily put 85 octane in my truck. Since I live in Denver with the higher altitude, the owner's manual points out no added benefit to using the higher octane 91.
 
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All kidding aside, I would run a inexpensive diesel 15W-40 until it starts getting cold in November, and then maybe a diesel 10W-30. In all honesty, with out knowing more about it, it is probably on its way out. Run it as inexpensively as possible until then. When is your next emissions check due?
 
The M1 HM 10w30 is an HTHS 3.5 which is a very thick 30.

Running some kreen or some BG109 in the oil to free up any potential stuck oil rings is something I would try. If that doesn't work I'd start running a 10w40 maxlife in the red bottle.
 
Since consumption is so high and consistent, I'd run nothing but a full-conventional Low-SAPS HD or SN PCMO with a narrower viscosity spread than 5w30. That could mean 5w20, 10w30 or low SAPS 15w40, depending on which side of the viscosity range the engine prefers to to consume.

The reason I'd move away from wide viscosity spreads is to reduce the amounts of polymeric VIIs that are consumed and burned (and consequently form deposits). The reason for Low-SAPS/SN PCMO for the same reason but regarding metallic ash production. The reason to observe consumption on both a high- and lo- vis engine oil is to determine which grade your engine prefers to consume (or to determine if there is even a difference)-- is it a blow-by, atomization and volatility issue of Starburst resource-conserving oil migrating through the PCV, or is it a piston ring tension issue, where the control rings slide over a robust oil film, rather than scraping it off the cylinder wall and away from the combustion side of the piston.

If you're resigned to adding oil every time you fuel up, those are the questions to answer IMO. There's no way I'd waste another penny behind using synthetic oil or even high-mile oil and costly conventional- the cheapest SuperTech will do. I wouldn't worry a bit about trying the 5w20 in the engine either, your problems are much bigger and threats much worse (like constantly running the crankcase low) than a 20 grade substituting a 30 especially in Denver with the fall and winter coming up.
 
Originally Posted By: Legend11
I've always heard great things about Mobile 1
High saturation, high-budget marketing n' all will generally have that effect
happy2.gif


psst, it's spelled Mobil, around these parts people will throw a fit if you add that extraneous e.
 
Originally Posted By: bigj_16
All kidding aside, I would run a inexpensive diesel 15W-40 until it starts getting cold in November, and then maybe a diesel 10W-30. In all honesty, with out knowing more about it, it is probably on its way out. Run it as inexpensively as possible until then. When is your next emissions check due?


Agree with this ^^^^^^ ditch the M-1 -overhyped- if you ask me.
15-40 diesel non winter and 10-30 diesel in the winter--Use the least expensive certified oil you can find-- Walmart (Super Tech)15-40 is real good for the price
Steve
 
Never thought of straying from Mobil 1 until recently. So the cheap WalMart SuperTech with 3000 mile oil changes is good enough? Wow, I feel like I've been throwing money away all this time. Still need to see how the truck runs after this 10w30 Mobil 1 High Mileage change.
 
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