Oil plunger

[Billy76]

I've got an 04 Nissan 4 stroke that the oil pump went out on. I'm replacing it and all the parts associated with the lubrication system just to rule out contamination. There's a part listed only as a plunger but the book says it a pressure relief valve for the oil system. It's also the only part I can't get because it's on back order and no estimated availability date from the manufacturer. I'm wanting to know how often they go out and if there's a way to test it?

 

[pvanv]

What model/serial? What book? What caused the pump to fail? The oil pressure relief plunger seldom fails. It is the pressure regulator, opening at pressures above normal. It can be tested.

 

[Billy76]

I lent the boat to my brother and told him it had a small oil leak at the pan gasket. I even keep an extra quart of oil in the boat. Needless to say when I got it back it was making a horrible noise from the bottom of the head and it had no oil showing on the dipstick. I'm just making an educated guess on the oil pump and hoping there isn't more damage. I.E. Cam or crank bearings and such. It will still crank and run and throttle up but I've only done that to test compression and oil pressure which it failed the oil pressure test. The manual I'm using is a SELOC and the model is a 2004 NSF18B2. I can get you the serial # this evening when I get home from work.

 

[pvanv]

Billy,

If you ran empty on oil, the pump could get damaged... But... as you start to get way too low, the pump has some oil, but not enough oil (lots of air bubbles) to pressurize the bearings. Odds are, if that happened, and the motor is still noisy with oil in it... the pump is good, but the rest is shot. That could mean connecting rods and or bearings. Does the oil light go out? What is the oil pressure on a gauge? Does it still make bad sounds?

 

[Billy76]

I thought about that but I hope that didn't happen. It's been about 8 months since this happened. I'm gonna get out there this weekend and test the oil pressure and compression again. I'll keep in touch and thanks for all the help.

 

[Billy76]

Just out of curiosity, let's say it is is rods and bearings. Does Nissan offer an overhaul kit for that motor?

 

[pvanv]

They have long blocks, etc.

 

[Billy76]

Ok. One more question and I'll leave you alone. In your years of experience would this problem also lead you to replace piston rings, wrist pins and cam bearing even if the cam and crank mic out good? I'm a heavy diesel mechanic of 20 years and under the same circumstances we would do a complete overhaul and replace all bearings.

 

[Sea Rider]

If engine run for extended time period with low oil level and much worst at wot, expect all internal rotating parts to be worn in some extend, that will only be possible to know once cranckase is split open. Right now it's a Pandora Box.

Happy Boating

 

[Billy76]

Thank you.

 

[pvanv]

Due to labor costs, I would probably replace the powerhead as a unit if it needed more than rods.