maximaah

iTrader: (1)

My 95 Maxima (72K miles) has started sounding like a diesel in the mornings when it first starts up. Temp about 60F.
Is this the lifters? Do they need adjustment after 60K?
Don't see this anywhere in the maintenance schedule...

vmok

What kind of oil filters are you using? I would suggest sticking with the Nissan oil filters as they have anti-drain back valves that try to keep oil in the upper parts of the engine, thereby providing lubrication upon startup. Many aftermarket oil filters, Fram, Wix, etc... may or may not have a properly functioning check valve. There's a good comparison on this on www.motorvate.ca. There is also a link there to another site that compared oil filters.

Another thing could affect the noise is the viscosity of the oil that you are using. Thicker oils may take longer to circulate to the top of the engine during cold starts. Synthetics may flow better in your engine as well under cold starts.

How long does the noise last? If it's not more than 5 seconds or so, I'd say you should be fine.

-V

Daniel B. Martin

The VQ30DE engine in all 4Gen Maximas does not have valve lifters, so no adjustment is needed.

When the engine is running the oil pump draws oil from the sump and sends it upward through passages called oil galleries to cool and lubricate all the internal moving parts of the engine. When the engine is turned off,
gravity will cause the oil in the galleries to flow "backward" through the oil filter and return to the sump unless something prevents that. The anti-drainback valve is a one-way valve (a "check valve") which prevents this from happening.

If the filter has a leaky anti-drainback valve the galleries become empty when the engine is not running. When the engine is started it takes a few seconds for the oil pump to refill the galleries. During that refill time
the engine parts, especially the valves, make an unpleasant knocking, clicking, or clattering sound. This symptom is more noticeable after a long period of rest, 24 hours or more.

Oil filters made for use in an inverted or horizontal position have an anti-drainback valve. This is true for all brands of oil filters. The difference (if any) from one brand to another is the material used and the quality of manufacturer. Any individual filter might have a bad anti-drainback valve.

The filter media, bypass valve, and anti-drainback valve are all internal parts of the oil filter. Therefore an oil filter is a "blind item" because the user cannot judge the condition or quality by sight, sound, smell, taste, or touch. When buying a blind item we make purchase decisions based on "image" factors such as the influence of advertising and brand loyalties. Choosing a good filter is further complicated by the fact that the same product may be sold under several brand names. Filter brands A, B, and C may be identical except for the brand name and exterior color. Industry insiders will know about this but most consumers will not.

If your engine exhibits the symptoms of a bad anti-drainback valve you should replace the filter. You might try a different brand of filter but (as explained above) it might turn out to be an identical product. I personally do not believe in the inherent superiority of the factory part but respect the opinion of those who do.

maximaah

iTrader: (1)

Thanks to everyone. I have an OEM filter, but both oil & filter are due for a change, so maybe the viscosity has gotten a little thick. I have a FRAM filter and Mobil 1 on the shelf in my garage, just waiting for a free moment...

vmok

There is an article on the www.motorvate.ca site that shows two oil filters cut apart and the differences of the two filters... one appears to be a Nissan filter and one a Fram filter. The differences are explained and shown in pictures. There is also a link on that site to Mopar site in which someone cut apart several dozen oil filters and measured the filter media, drainback devices, canister specifications, etc...

From that site, it appears that Motorcraft, Purulator, and some Wix filters were good. However, the test was limited in that it tested a common oil filter used in many Ford vehicles, the FL1 or PH8A (Fram), that's used in everything from the Crown Vic, Ranger, Explorer, to F Series trucks.

-V

Whitemax

I was suffering from a very similar problem. My mechanic told me that it was the tensioner for the timing chain, and also could tell I was running synthetic oil by the noise. told me to run regular oil, or run Quaker States High milage oil. Corrected my problem. I don't know if Daniel will concur with this possibly being your problem, but I did read that its a common issue with 95-96 models......