2001 Nissan Pathfinder with high silicon & lead in UOA

[nheitz]

Ok, I'm frustrated. I have a 2001 Nissan Pathfinder with just over 100,000 miles. This is Nissan's 3.5L VQ series V6. I've been getting high silicon & lead readings from used oil analysis and can't figure out what's going on. The air filter seems to have a good seal & it looks clean just downstream of the filter. I don't see any obvious cracks on the intake. I did not have good luck with Amsoil Synthetic 5w30 running it for 1 year with their air filter & oil filter. I did it for 1 year & did not get good results... way out of viscosity, 0 TBN, & high wear metals. I can't find a copy of that UOA to post. Anyway, I decided to try it again for a year & had similar results. Here is that UOA. [IMG][/IMG]I then ran Amsoil Synthetic 5w30 for 6 months & here is that UOA. [IMG][/IMG]Then I switched to Mobil 1 5w30 & filter & replaced the Amsoil Ea air filter with a new Nissan OEM air filter to see if that was where my silicon was coming from. I ran this for 6 months & here is the latest UOA. [IMG][/IMG]Please help!!! What do you guys think?

[anthonyc]

http://www.bobistheoilguy.com/...s.php

[nheitz]

I already posted on BITOG. Thanks though. I'm looking for some Nissan specific information.

[nheitz]

Based on the silicon levels it seems like I'm getting dirt in somewhere, but I'm not exactly sure how to find out where. Some have suggested a vacuum leak, a PCV leak, or a leak in the air intake plenum.

[Issac]

Seems to me like a PCV is possible. They are not expensive. But also the intake tube could have a coat also along with TB, unless you cleaned them when you changed filter. Just guessing on things. Also you can hit your Mass Air. The intake clamps and seal obviously need checked.

I have no proof, but I suspect it was air filter related.

I was interested in your oil analysis. Seems the synthetics were not all that, or maybe the dino oil would have been real bad.

I would be curious to see what your results of 5k worth of GTX would look like-for example.

[nheitz]

"But also the intake tube could have a coat also along with TB, unless you cleaned them when you changed filter."What do you mean it could have a coat & what is TB?

"Also you can hit your Mass Air."Is it hard to clean on the 2001 PF? Can someone tell me how?

"Seems the synthetics were not all that, or maybe the dino oil would have been real bad. I would be curious to see what your results of 5k worth of GTX would look like-for example."Both oils are good quality PAO IV synthetics so I have a feeling the dino oil would have been really bad. Last time I filled with Castrol Syntec 0w30 (German made) so we'll see how it does. However, I don't think it will be any better until I get this silicon level taken care of. Anyway, thanks for your help.

[fueler]

TB is throttle body, they get dirty easily MAF is first removed, then carefully cleaned with electrical contacts cleaner in aerosol can

[SnowSurfLax]

I just take the top off the air box and spray the cleaner through that. No need to take the MAF out and risk breaking it that way.

[fueler]

I just take the top off the air box and spray the cleaner through that. No need to take the MAF out and risk breaking it that way.

Good, efficient way!

[Issac]

Still want to unplug the sensor!

German 0-30 Castrol. I was just reading up on that. Sounds like the stuff. I am going to try to hunt it down. Castrol is a great company. I was thinking if your oil was that bad after so few miles, maybe the synthetics are getting lower quality. I heard that Mobil 1 is lowering additives, like Calcium to keep CATs clean.

I am going to try that oil. If you don't mind, let me know the results of your next oil check.

Also there might be residue was what I was saying. The filter might have been laying down a coat upstream? Just a guess, so you go in and clean the whole duct.

Also maybe clean out your airbox and the intake snorkel. I yanked mine, because it chokes the truck down much and I don't go under water