Oil Pump Replacement

[slim_jimmy7]

Going to put in a new oil pump because the gasket on the old one leaks and thought as long as I'm in there I'll put a new pump in.  So I looked at the process to put in the pump with the manual that I downloaded and they seem to make this process seem like a huge undertaking.  How hard is it to do this?  Can I just line it up with TDC, take off distributor, and swap it out or do I need to do something more?

[metalmonkey47]

It's super easy. No need to mess with timing the motor (other than re-checking ignition timing and making minor adjustments when done). Probably less than an hour for the average Datsun mechanic.

-Mark distributor location and remove distributor

-Used needle nose vice grips or equivalent to grab the top of the oil pump drive spindle. Clip the top to keep it from falling down when you remove the oil pump.

-Unbolt oil pump, drop it out of the way.

-Clean gasket surfaces, be sure to fill the pump with oil and prime it before installing the new pump

-Install freshly primed pump. You won't need to do anything more than rotate the pump to line the end of the drive spindle up with the slot in the pump, provided you used methods in first step to properly hold the drive spindle in place. Once it's in place, you're pretty much done.

-Grab your timing light, check / set ignition timing. Viola! You're done.

You may have to loosen the sway bar, IIRC I had to do so on either my 620 or my 240Z to slide it out. This may not be necessary on a 510, maybe others can chime in.

Buy either a KA24E oil pump from an '89 240SX or L28ET oil pump from a ZX Turbo. Both are direct swaps and much better than the original L16 oil pump. (higher volume) I like Melling brand oil pumps and used them on all my L motors.

[slim_jimmy7]

I got a M152 Melling pump, and thank you for the response, I was hoping that was the case!

[yenpit]

Orange City?  Jon?  :confused:

 

TJ

Denver

[slim_jimmy7]

That's me!  I thought I was the only one in Iowa, it turns out I think there is someone with a 510 in Des Moines

[Roadster-ka]

Long screw driver lightly jammed alongside distributor driveshaft will hold it while you change the pump.

[datzenmike]

KA24E but not the KA24DE oil pump from an early 240sx or the oil pump from any year KA24E or DE from the Hardbody. Never had a 280zx pump apart so can't say about them being exacxtly the same as the KA... probably.

 

Can't tell from the outside, the difference is all internal. Look down into the oil inlet hole and on the KA pumps you will clearly see the top of the pump rotor...

 

 

 

On the regular pump the rotor is barely visible...

 

 

This is because the KA rotors are 13% longer...

 

 

Hot idle on very old L20B was 17 PSI. With no other change but a well used junk yard KA pump it jumped to 29. Top pressure is always governed by the relief valve spring... usually 55-60 PSI. The KA pump will give higher idle and low speed pressures. Check your new pump and make sure you are getting what you paid for.

 

.

[edekalil]

Always learning good info from you Mike.

[datzenmike]

It would be so easy to be sold a regular pump in place of a high volume one. I have KA pumps on all my L20Bs and my L18 I just sold.

[slim_jimmy7]

Was going to replace it last night but since it is apparently monsoon season, I needed to vacuum water out of my basement instead. I will look down the oil inlet hole before I start.

[wilfredmatias]

Hello, 

 

I came across with this thread also and I do have a question.  I replaced  the timing chain for my 1980 datsun 510 because it was rattling when cold. I still have the problem despite changing  the timing chain kit. Should I replace the oil pump? Should I look to something else?

Thanks in advance!

[ggzilla]

You should look at the installation of the timing chain

 

* remove the valve cover

* loosen the guide bolts

* pry the guide all way to take up the slack

* re-torque the bolts

 

The oil pump feeds the tensioner. But it only takes a few pounds of oil pressure

 

The tensioner won't compensate for loose guides

[datzenmike]

6 hours ago, wilfredmatias said:

Hello, 

 

I came across with this thread also and I do have a question.  I replaced  the timing chain for my 1980 datsun 510 because it was rattling when cold. I still have the problem despite changing  the timing chain kit. Should I replace the oil pump? Should I look to something else?

Thanks in advance!

 

When you replace something and it doesn't help a problem you really have to consider that the part replaced wasn't at fault in the first place.

 

Valve clearances will rattle when cold but as the engine warms the clearances close up from thermal expansion. Hot clearance on a Z series engine is 0.012" for intakes and exhaust. I would check and set this first. I've also heard Z series owners say their engine noise indicates that it is due for an oil change and gets quieter after. Always change the filter with anything but a fram. WIX is good or NAPA Gold.

 

You sure it's the chain? Could be rod clearance, quiets almost instantly when oil pressure builds. You could try 15w40 Rotella T4. Should be using a high zinc oil anyway. 

 

Likewise piston slap caused by wear and excessive piston to wall clearance on a tired engine when cold. The piston rocks in the bore as it changes direction at TDC, quiets as engine warms and tightens from thermal expansion. 

 

 

[wilfredmatias]

On 6/13/2025 at 11:30 PM, ggzilla said:

You should look at the installation of the timing chain

 

* remove the valve cover

* loosen the guide bolts

* pry the guide all way to take up the slack

* re-torque the bolts

 

The oil pump feeds the tensioner. But it only takes a few pounds of oil pressure

 

The tensioner won't compensate for loose guides

Hello, thanks for your reply.  Everything  is brand new Japanese brand. After installation  we spent 32 mins using a ratchet to check any slacks and finally  get the timing marks  back in place.The chain doesn't  have any slacks, bolts were torque as recommended.

[wilfredmatias]

17 hours ago, datzenmike said:

 

When you replace something and it doesn't help a problem you really have to consider that the part replaced wasn't at fault in the first place.

 

Valve clearances will rattle when cold but as the engine warms the clearances close up from thermal expansion. Hot clearance on a Z series engine is 0.012" for intakes and exhaust. I would check and set this first. I've also heard Z series owners say their engine noise indicates that it is due for an oil change and gets quieter after. Always change the filter with anything but a fram. WIX is good or NAPA Gold.

 

You sure it's the chain? Could be rod clearance, quiets almost instantly when oil pressure builds. You could try 15w40 Rotella T4. Should be using a high zinc oil anyway. 

 

Likewise piston slap caused by wear and excessive piston to wall clearance on a tired engine when cold. The piston rocks in the bore as it changes direction at TDC, quiets as engine warms and tightens from thermal expansion. 

 

 

Hello, thanks again.  Everything  is new. The noise goes away after a few seconds. I forgot  to mention if I try to start it up at least 3 times, after that when starts it doesn't  make that noise. I am assuming  because  the parts got lubricanted. I bought  a high mileage oil  at NAPA and the filter, but isn't  the gold one. I will check the valves adjustment. I always change the oil  every  3,000 miles.  Thanks again!!

[datzenmike]

Seems that it goes away as soon as the oil pressure goes up. 

 

Rather that replacing the rod bearings and then find out it didn't help, I would first get a KA24E or DE oil pump from an '86 and up D21 Hardbody. It's a high volume output and will push more oil at cranking speed and as soon as it starts. I just get them used from a wrecking yard. Cheap and easy enough to swap. Truth is, a little rattle on start up won't hurt anything. 

 

The KA internal rotors are 13% longer for more volume...

 

[wilfredmatias]

On 6/15/2025 at 7:19 AM, datzenmike said:

Seems that it goes away as soon as the oil pressure goes up. 

 

Rather that replacing the rod bearings and then find out it didn't help, I would first get a KA24E or DE oil pump from an '86 and up D21 Hardbody. It's a high volume output and will push more oil at cranking speed and as soon as it starts. I just get them used from a wrecking yard. Cheap and easy enough to swap. Truth is, a little rattle on start up won't hurt anything. 

 

The KA internal rotors are 13% longer for more volume...

 

Hello,

 

Many thanks! I bought it already.  I will keep you guys posted!

[banzai510(hainz)]

you filled the new pump w oil before install? Anti backflow valve in oil filter? Had this on my jeep. Tickn for 2sec.  If chain tight/new that part i call it good

[wilfredmatias]

On 6/15/2025 at 7:19 AM, datzenmike said:

Seems that it goes away as soon as the oil pressure goes up. 

 

Rather that replacing the rod bearings and then find out it didn't help, I would first get a KA24E or DE oil pump from an '86 and up D21 Hardbody. It's a high volume output and will push more oil at cranking speed and as soon as it starts. I just get them used from a wrecking yard. Cheap and easy enough to swap. Truth is, a little rattle on start up won't hurt anything. 

 

The KA internal rotors are 13% longer for more volume...

 

Hello,

 

Many thanks! I bought it already.  I will keep you guys posted!

[wilfredmatias]

Hello,

 

I have installed the KA 24 E oil pump. Everything  went smooth! I just want to pointed out that the rattle noise went away after the 2nd time starting up the car. Besides of this, I ended  up installing  the new oil pump. 

 

Thanks everyone  for your help and replies. I really  appreciate that.

[banzai510(hainz)]

should of been a little more clockwise right of top hole.left on bottom. but if ur in time . Drives ok up hill call it good

[wilfredmatias]

16 hours ago, banzai510(hainz) said:

should of been a little more clockwise right of top hole.left on bottom. but if ur in time . Drives ok up hill call it good

Hello,

 

Yes, you are correct.  I need to spin it a little  more clockwise.  I will do that. Its not going  fast uphills. 

 

Many thanks!

[datzenmike]

Use a timing light. If you can set the timing @ 3 to 5 degrees, (check the owner's manual for correct amount) then it doesn't need changing. Don't fix what isn't broken.

[banzai510(hainz)]

if you had it where it was pulled and put back in should be ok.( i think)

I persoanllly hate that way to do it I pull the whole thing. Done them in parking lots. put to exact TDC on crank then pull notice where the spindal is in case someone did it different earlier. then put back in.

 

go to 47mins

 

Edited June 20 by banzai510(hainz)

[wilfredmatias]

On 6/19/2025 at 9:00 PM, banzai510(hainz) said:

should of been a little more clockwise right of top hole.left on bottom. but if ur in time . Drives ok up hill call it good

Hello,

 

Yes, you are correct.  I need to spin it a little  more clockwise.  I will do that. Its not going  fast uphills. 

 

Many thanks!