G35x couple oil questions

[mac9128]

Okay so I'm trying to help out my parents with this one. My father has an 08 G35x and my mother an 06 G35x. They both run Valvoline Synpower oil changed at the quicklube with whatever filter they use there. They usually let it go 6-8k between changes. Now the 06 is getting up in miles close to 80k I was wondering if it would be good to switch to a high mileage oil yet like maxlife? In the 08 I've noticed that after the 5-6k mark without an oil change the car feels slightly sluggish for some reason until it's changed again. I was wondering if you guys have any specific oil recommendations for these cars or if any comments on the sluggish feeling in the 08? any help is appreciated, thank you.

 

[santov]

Might want to check with some of the UOA, I think 6k is ok on the high end, but 8k is pushing the oil. Nissan/Infiniti VQ engines are really tough on oil. For your mom's 06: 80k miles isn't enough to warrant changing oils. If it works it works. I suspect the "high milage" comes from an extended OCI, not an engine with high miles.

My experience with my wife's 05 FX35 (same engine and drivetrain as G35x): Check the plug seals there was a bad batch of seals that allowed oil to seep into the spark plug tubes. Grease the tensioner pulleys. When I did a belt change the bearings were making noise. After a good greasing the engine ran much quieter. Clean the throttle body. Mine was gummed up with deposits. After you put it back you have to run a simple reset procedure for the servo inside. All you need is a $4 replacement gasket.

Here's a video. You'll notice a much improved throttle response.
http://www.youtube.com/watch?v=KwdYzWzc170

Of course there's all the other maintenance, spark plugs, air filter, etc.

I know that Infiniti inside and out now. I'd feel safe buying a used one with high miles since they're pretty dependable.

 

[chubbs1]

Do you live around your parents? It would be nice if you could change the oil for them so you know what is going in, it must be outrageous to get Synpower at a quik-lube. Then you have to trust they put it in. SynPower is a very good oil so I wouldn't change to Maxlife, there is no reason to change to a "high Mileage" oil at any given point. They are usually for when your car leaks or has some consumption issues Maxlife has Esters that help condition/swell the seals and it also as a higher viscosity which will not help the "sluggish" feeling in the 08. That is an odd one to me, You may want to try a different oil like Pennzoil Platinum or Ultra, M1. Those are oils you can get at quik lubes if that is all your folks have to revert to. Amsoil, Redline, RLI are some awesome true Synthetic oils that you can purchase and have someone put it in. Hope this helps a little.

 

[santov]

Oh, I should add that my FX has only ever had the Castrol syn blend from the dealer or Mobil 5000 5w30 since it's so dang cheap. The last couple UOA came back great.

 

[mac9128]

Have never done a used oil analysis, and the sluggish feeling is weird but now that you mention it my father doesn't really believe in preventative maintenance or fixing something before it breaks (kindof a long story) so if I tell him to order spark plug wires, plugs and stuff and I'd change it he'd say no he doesn't need. Probably 50-60k miles on the 08 but he drives a decent amount yearly. I'm a student in state at URI I'm only 19 so I live with them during breaks and summer but at school most the year so they stick to the quicklube generally. But i'll look into the throttle body thing because his car doesn't seem the same as when he got it, it has twin smaller tb's actually so twice the cleaning yay haha. I really won't have the time to do all their changes but there is a place locally that does changes for $20 if you bring your own oil and filter close to the house so I can send him to autozone, walmart, etc and tell him what to get and bring it there and he'd do that. Maybe I'll have him look into Mobil 1 with a pure or Mobil 1 filter and 6-8k OCI's and check the TB and plugs and see how everyting looks. Thanks for the help guys.

 

[aquariuscsm]

I wouldn`t go with a high mileage oil. Just stick with your usual Synpower. Use a 40 weight.

 

[dparm]

I'd keep doing what you're doing unless you have money burning a hole in your pocket.

 

[mac9128]

well the Mobil 1 oil and filter plus change would be cheaper than they're paying now so its actually saving money.

 

[dparm]

Pep Boys has $32.95 for 5qt Mobil 1 + Mobil 1 oil filter. Deal is running through 1/31.