Jump to content

Bad oil pump?


Sierra

Recommended Posts

  • Replies 34
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Thanks for the response racerx,

I definitely have a very noisy valve-train and the oil presume light is on even after I replaced the sensor.

It also has low power. I checked compression on all four pistons and all average 90 psi.

Link to comment

I was just looking at my service manual so I can get the right pressure numbers.

So the ideal pressure should be between 170 and 190 PSI, based on that, I am way low.

 

I also realized that I did the compression test with the throttle valve close.

 

I adjusted the valves cold at .25mm

 

I will post an updated tomorrow when I redo the compression test correctly.

 

Thanks again for your feedback.

Link to comment

Boy, who knows...

 

Since this oil pump is driven by the cam, it's possible that the gear on the cam just wore out and chipped a tooth. Maybe the engine sat for a long time and rust formed on the gears. Maybe there was foreign debris in there somewhere. The lifters on these engines can chip on the edges, maybe that happened and a chip found its way to the gear and got jammed. One other possibility is that the oil pump froze (from lack of use or poor maintenance) and the gear couldn't take the beating.

 

I doubt the cam is in good shape after that failure.

  • Like 1
Link to comment

Sorry to keep all of you in suspense.

So, this is the story.

Got the engine, rebuilt already by a shop from previous owner.

I got the oil pump from ebay.

I was the one that installed the engine and placed all other essential parts in order to have a working power plant.

This was my first time replacing an engine.

After this mishap, I did some research and talk to some more experienced Datsun guys.

Long story short.

I did not bled the oil pump.

I simply installed it and then install the filter.

For some of you that do not know (like me) you need to bleed the pump in order to get the oil pump gears lubricated. Since I failed to do so the gears simply got to hot to quick and ceased to move.

Causing the damage you see in the picture.

Very expensive learning lesson for me.

Now, I am opening the engine so I can inspect the damage.

since I run the engine 3 or 4 times for about 5 to 10 minutes each time.

And that's what happen.

Link to comment

I doubt this. You should be able to start this dry and have oil in seconds.

 

Probably a shitty eBay pump cheaply made in China. This is the real lesson learned here. Buy quality made in Japan pumps if replacing them. If buying Chinese, only get floor mats... no one cares if they break. 

Link to comment

Sorry to keep all of you in suspense.

So, this is the story.

Got the engine, rebuilt already by a shop from previous owner.

I got the oil pump from ebay.

I was the one that installed the engine and placed all other essential parts in order to have a working power plant.

This was my first time replacing an engine.

After this mishap, I did some research and talk to some more experienced Datsun guys.

Long story short.

I did not bled the oil pump.

I simply installed it and then install the filter.

For some of you that do not know (like me) you need to bleed the pump in order to get the oil pump gears lubricated. Since I failed to do so the gears simply got to hot to quick and ceased to move.

Causing the damage you see in the picture.

Very expensive learning lesson for me.

Now, I am opening the engine so I can inspect the damage.

since I run the engine 3 or 4 times for about 5 to 10 minutes each time.

And that's what happen.

Truly you mean PRIME the pump, not bleed!

  • Like 1
Link to comment

I doubt this. You should be able to start this dry and have oil in seconds.

 

Probably a shitty eBay pump cheaply made in China. This is the real lesson learned here. Buy quality made in Japan pumps if replacing them. If buying Chinese, only get floor mats... no one cares if they break. 

Agreed. Engines sit for long periods and the oil drains out. They are self priming pumps.

 

Take the pump apart and look at the gears. Are they scored on the end (flat) surfaces? Is the housing scored anywhere? I bet the pump was built too tight to begin with and bound up.

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.