I've been using Mobil 1 Full Synthetic 5w-30 'last 15,000mi' supposedly oil, been using it for about a year change em every 3000mi or so. The issue im having is when I have about 1500mi on it, and when im coming to a stop the oil light will come on. Dealership recommended a new oil pan?? Or should I just use Nissans Conv. Oil? I burn about 2quarts ~2000mi.

 

With that kind of consumption and the oil light being on I'd switch back to conventional, conventional oil runs higher pressure (fixes the oil light problem) due to larger molecule size (which also makes it harder to get past rings and valve guides thus helping the OC problem). I like the Nissan oil and the nissan dealership is only like $32 for an oil change so.... I watch TV for an hour and they change my oil.

I would only replace the pan if it had obvious signs of damage, buy it online and do it yourself though, the lower pan is only about $50.

 

alright man ill keep this in mind when I do my next oil change, thanks dude!

 

What part of South Dakota are you located at? I’m in Sioux Falls basically every day.

 

That dude posted that back in 2014.

 

lol I know still interested tho

 

There's a few variables, are you tracking the car, is the motor built, what's the ambient temp. For a stock engine with OEM bearing clearances just stick to stock viscosity. Mostly the oil viscosity is determined around bearing clearances anyways, ambient temp just gives a few options.

Factory 5W30 is fine if you aren't tracking the car and it's cold, summer time use 10w30
A built motor probably is going to be using 10w40 or thicker but that depends ENTIRELY on what bearing clearances were used. I've seen 15w50 for some really hot VQ's.
Track use you probably want something a bit thicker than OEM viscosity, 10w40 if you're planning on doing a lot of hot laps, if it's just a few drag pulls and you aren't hot lapping too many times just stick with OEM viscosity recommendations.

If you're talking about the S/C oil then you want to use the Vortech proprietary synthetic oil that gets replaced every 7500 miles.

 

I bought my 2005 g35 about 3 years ago and have put about 30,000 miles on it(it's got about 170,000 miles on it) I changed it to Mobil 1 on the first oil change(5W30) and that's all it's had since. It has always "chattered" just a little on start up if it sits a few days but it never smokes and runs great. Question is, I have no idea what oil the previous owner ran in it but it seemed to have been maintained pretty well. Would I be better off going back to conventional oil as it seems that from looking at these posts that the synthetic thins out a bit or possibly go up to 10W30 in the synthetic? It's in the southeast and temps range from 20-100 at different times.

 

Viscosity doesn't change the size of the molecule, if you are consuming oil then you should probably just use conventional. That timing chatter is probably the primary tensioner, they're only good for about 100k.

 

Really doesn't burn any oil but I've got to address the usual leaking valve cover and I thought I'd read mentioned that synthetic seemed to make that worse ala my assumption synthetic was molecularly smaller. Thankfully my engine has the access cover's so I may make a party out of it and do valve covers, tensioner, and water pump at the same time.(Are the a/m pumps any good)

 

You should just use synthetic (since you aren't consuming oil from burning it, leaking it out doesn't count), it provides better protection with the current GL-4 oil they're selling on the shelf, if you're using off-the-shelf oil.

The BEST type of oil for our engines is the older GL-3 oil but you can only get that with "racing" oil since our emissions overlords deem that too much zinc makes catalytic converters last 5% shorter lifespans so at the cost of emissions our engines experience +25% greater wear.

I'm INCREDIBLY salty about how our oil provides WORSE protection every 10 years or so when the API comes out with a new GL-type of oil.

The VQ35DE was designed for GL-3, zinc/phosphorus levels. The quick and dirty about how and why it matters, in your bearings there's a LOT of pressure squishing the oil molecules, when they're squished hard enough they explode, it's called "oil shear" and the molecule is essentially USELESS after that point (synthetic is a more durable molecule and doesn't shear as badly). To prevent it from being metal-on-metal when the oil shear occurs they add zinc and phosphorus to your oil, the metal parts can ride on this ultra-thin zinc molecules so they aren't grinding against one another.

However, zinc destroys the catalytic converters, engines burn oil (all engines, not just the G35, they ALL burn oil to some degree, most engines consume very little oil).

GL-4 oil which is the most common on the shelf (GL-5 was just introduced and not really common yet) has substantially less zinc and phosphorus, it's not LEGAL for them to sell GL-3 oil anymore due to the EPA restrictions via the API, American Petroleum Institute who makes these GL-# gradings for oil. I think it's a gigantic conspiracy to make older engines fail more quickly, the lower zinc/phosphorus levels from newer GL4 oil in an engine designed to burn GL3 causes engines to fail mathematically about 15-25% faster due to less protection on the bearings.

Engines built during the era of GL-4 use very tight machine tolerances and OEM oil typically has a bunch of other additives to help offset the lack of zinc/phosphorus, they're engineered to use GL-4 so they don't exhibit the same wear as an older engine.

The API knew they ****ed up with GL-4 and they didn't have ENOUGH additive requirements, they've sort of pulled back a little on the GL-5 since most of your engines built through 2008-2017 are only getting about 100k miles on average before they're consuming a QUART of oil per oil change, all manufacturers are having these problems right now. The longevity of engines has suffered pretty badly in the last decade.

GL-5 oil became mandated a month ago I think, you'll start to see it on the shelves soon, it's too early to tell if it's better or worse than GL-4 because there haven't been enough cars using it for enough miles. However every change in oil has meant less protection for the bearings and rings ever since they started pulling zinc out.

I personally use Valvoline VR1 10w30. It's not much more expensive than any other conventional oil but it has all the same zinc/phosphate levels that GL3 oil used to have which is basically what the VQ35DE was designed to run with.

 

OEM oil usually has a set of additives that are designed as closely as possible to fill in the blank spots where generic GL-X oil doesn't offer the proper lubrication for engine longevity. It's like a big game of tetris, the OEM makes the pieces that fit as perfectly as possible for THEIR ENGINE while still being API compliant. Off-the-shelf oil will certainly provide lubrication but the metallurgy is different from one manufacturer to the next and the OEM typically has a very specific recipe that they use that provides the best protection for THEIR ENGINE.

As for the water pump, I normally use OEM equipment for any water pumps. I've had too many bearing failures over the years with aftermarket ones. An aftermarket is probably $50-60 whereas the OEM Nissan pump is $100 but I know for sure that pump isn't going to have a bearing go out at 60k miles.

 

Thanks, I appreciate the info. I don't have any experience with this type engine as all I've fooled with in the past were pushrod V8's. And I'll let Infiniti sell me a pump, I hate re-do's.

 

Check out the online vendors, for example Z1 Motorsports sells OEM Nissan components for a heck of a lot cheaper than my local Nissan so I usually buy stuff from the or infinitipartsonline.com . They are an Infiniti dealership in AZ that has great online prices.

You can use the Z1 site to get the part number, they list Nissan#'s at the top of the part page.

 

Man, you make it sound like our engines explode six times with every turn of the crank. It's a miracle we even get down to the corner in the morning!