When the engine is cold and I start the car the engine rpm would go to 400rpm and then the oil light would flicker and then rpm would go up to 500rpm.When I stop a stop light the rpm would drop to 400 the oil light would flicker again. I don't know what could be the problem.

 

Maybe the throttle body needs cleaning, maybe the MAF is going bad.

Is the check engine light on?

 

The check engine light has not come on.

 

when was the last time you changed your oil? the vg engines run really hot and are known to burn oil.

 

This is the 4th gen section. VQ.

 

My engine has never burned oil nor run hot with 143K on it.

 

Its been about 5000 miles since my last oil change. Is the vq engine known to burn oil or were you talking about the vg engines?

 

Vq35 yes oil consumption....Vq30 (yours) not soo much. The oil pump is chain driven so at very low rpms (below 500 rpm) you should expect the oil light to come on. The idle speed IIRC is 700-750 rpm for a manual tranny VQ30.

That cold, low idle could mean you need to clean your throttlebody.

 

And clean your IACV. No doubt it is carbon fouled as well. Use specifically formulated TB cleaner not just any 'ol carb cleaner so as not to remove the finish off the butterfly other parts etc. You need a minimum idle speed to drive many thing: oil pump, trans pump if an auto, alternator etc.

And yeah my '97 doesn't burn a drop of oil, (leaks some) and never ran hot a day in life. It just rolled 350K last month. Amazing motors the VQ's. 7-800 rpms ought to get you where you need to be after a cleaning. Great How-To's in the How-To section. Easy Saturday morning project.

 

Your idle speed is too low. The oil pressure increases with engine speed, up to a point. Increase idle speed to specifications. Your engine is fine.