Engine Noise ?

[devinwest1984]

I have a 93 pathfinder and after it has set for a while like overnight at startup for a second it makes a horrible clacking noise like it is starving for oil. it is not exhaust manifold noise, this is different it sounds like really loud lifter noise. my oil level is full and I had an oil change 600 miles ago. this is new since the last oil change. should I change the oil again? has any one else experienced this issue. I had a mechanic tell me that the sound is the engine starving for oil. he suggested running seafoam in the oil and changing it again soon does this sound reasonable? my pathfinder has 176000 miles on it.

[Simon]

It is the lifters. It's pretty common. Mine does it from time to time at startup as well. Seafoam didn't do anything. The only thing that does, is running Lucas Oil stabilizer (1/2 Litre) every oil change. That seems to keep it quiet. As long as it only does it for a second or two at startup, it's not really hurting anything though.

[devinwest1984]

I think I may have solved this one myself I hope. I talked to state line nissan in kansas city and they said nissan oil filters have a rubber flapper that acts as a check valve and prevents the oil from running out of the filter. most aftermarket filters do not have this flapper and over time the oil drains out of the filter and causes the oil system to need to be reprimed. I plan to replace my oil filter and see if that solves the issue. the other thing that I have been told could be a suspect is the oil I am useing (I switched from a conventional oil to casterol gtx synthetic blend) so to divide and conquer this issue if the filter does not solve it I will change the oil again. I have also done some research I just got this vehicle recently and I am not sure which oil was used in this car during it's life but it may have been penzoil if it was penzoil it contains a perafin based addative that sticks to the sides of the engine and traps dirt. this is not an issues unless you switch oils to a high deturgent oil which disolves this parafin coating. if the coating disolves in high milage engines it can clog oil journels and cause major engine issues. I think useing an oil stabilizer at this point to solve this issue may be premature and it will thicken the oil and possibly complicate the issue. I will post more on this issue as I solve it. I have also been told by a mechanic I trust that this will not harm the engine as long as you do not hit the throttle while it is noisey.