KA24E oil pressure/pump

[DavidM]

I'm prepping the car for racing at Barber over Labor day. Got all the fluids changed and cranked it up. It's been many, many months since it's been started. It started right up, but the oil pressure seems low. I was seeing around 20psi right after it started. It's in the 80s outside, but I would expect the pressure to be a little higher right after startup. I'm running redline 30wt racing oil.

I have an electronic gauge and the sending unit was seeming a little flaky last time out so I'm going to get a new one and see if I get the same readings. If I still get low readings, is that pretty indicative of a weak oil pump? Could it be anything else? No major leaks that I see.

How involved is replacing the pump? It doesn't look too terribly bad. I just picked up a spare pump from Tristan so maybe that's why it went.

Thanks.

David

[erlrich]

David - was it running 20psi when you rev'd it, or was that at idle? If at idle that's about what mine sees, I wouldn't worry too much - as long as you're getting around 60psi when you rev it to 2k or more. Also, are the lifters ticking? If it has been sitting for that long they may be dry; you'll need to run the motor for a few minutes at an elevated rpm to get them pumped back up. I don't think that will affect oil pressure, but maybe? I would definitely start with the gauge, and see if that makes a difference. Is the factory gauge still hooked up...or did we get an idiot light? I can't remember off the top of my head, I haven't looked at them in years.

The pump is pretty easy to change - just make sure you mark where the rotor is before you pull the distributor, and where the slot in the end of the pump shaft is in relation to the distributor; you'll need to get it back into the same position when you replace the pump. It sometimes takes a few tries, as the shaft turns a little when it engages the drive gear on the crankshaft.

[DavidM]

This was at idle, which is around 1500 rpm when the motor is cold. I reved it a couple times, but didn't hold it in case something was wrong. I didn't see the psi go up a whole lot, but maybe it takes a second or two for the gauge to adjust (or maybe that's the sender being flaky). I don't think I've ever seen close to 60 psi except at high revs. Definitely not at 2k rpm.

There was a lot of ticking when the motor first started, but it went away after a few seconds. The motor sounds good and I wouldn't be concerned except for the oil pressure readings. I shut it down for the night to think on it some. I'll work on it some tomorrow night and see what I get when I hold the revs for a bit.

Thanks.

David

[CCARVER]

I will bring all of my E spare parts if you do not have this thing totally fixed we can work on it there.
I will be bringing the gas can for the DE, because if it does not work I will be setting it on fire.
See you guys track side.
Carver

[DavidM]

Thanks for the offer. Hopefully I'll have it fixed one way or another before I leave. I have a spare pump so it's just a matter of putting it in if the current one is bad.

I do have a couple questions on replacing the pump.

- What I've read says to put the #1 cylinder at TDC on compression. Dumb question, but how do you know when it's on compression if you can't see the valves? Timing mark? Also, I presume I can pull the plugs and turn the crank with a socket or wrench?
- I don't need to pull the distributor, right? I just need to take off the cap and mark where the rotor points?
- The FSM and a write-up I found talks about replacing a seal along with the gasket. I looked at the schematics on courtesyparts.com and the only seal I saw is for the pick-up tube. Is that the one? The local dealer had gaskets in stock so I have a couple of those now. Just wondering about this seal.

Thanks again for any pointers.

David

[erlrich]

- What I've read says to put the #1 cylinder at TDC on compression. Dumb question, but how do you know when it's on compression if you can't see the valves? Timing mark?

The valve cover is so easy to pull on these motors I would probably just do that; but just as easily you could pull the distributor cap - making a note of where #1 wire was - and turn the motor until the rotor was almost at the #1 contact on the cap. Then used the timing marks to get TDC.

Also, I presume I can pull the plugs and turn the crank with a socket or wrench?

Yes.

- I don't need to pull the distributor, right? I just need to take off the cap and mark where the rotor points?

Unless I was doing it wrong, you do need to pull the distributor. The is a notch in the end of the oil pump shaft that engages the distributor shaft; those need to be aligned for the oil pump to seat all the way. I found the easiest thing was to pull the distributor first, then make a mark on the block (or take a picture) so you'll know which way the notch was lined up - you'll have to put the new one back exactly the same way. That's what I was talking about when I said you may need a few tries to get the shaft in the right position; it turns a few degrees as the gear on the shaft engages the drive gear on the crankshaft.

- The FSM and a write-up I found talks about replacing a seal along with the gasket. I looked at the schematics on courtesyparts.com and the only seal I saw is for the pick-up tube. Is that the one? The local dealer had gaskets in stock so I have a couple of those now. Just wondering about this seal.

Thanks again for any pointers.

David

I don't remember where, but I seem to recall some seals and other shit in there; actually, Rock Auto shows this when you pull up the oil pump seal, those parts all look familiar but it's been a couple of years since I did mine so I can't remember where they all went...sorry.

[DavidM]

Thanks. Guess I'll be taking some pictures if I have to go in. I'm still puzzled by the seals. This is what is shown on courtesyparts.com:

http://www.courtesyparts.com/240sx-p...1420_1435.html

Looks like maybe a couple of those pieces go on the distributor side:

http://www.courtesyparts.com/240sx-p...1449_1451.html

I can't figure out the other two.

David

[erlrich]

If I recall correctly, a couple of those go between the block and the timing chain guide, or the block and the t/c cover...the large seal is obviously for the crank, the o-ring may be for the distributor. I'm not sure you need to replace any of those just to change out the pump.

[Tristan Smith]

David, the only gasket you need is the one numbered 15066. I would change your oil gauge sender first before I changed any of the other parts. If you still get readings that you consider low, I would think about changing the oil pump.

I don't recall what my cold oil pressures were, but I don't think you are seeing anything dangerously low. Especially if you haven't warmed up the motor and rev'ed it up to see what you are getting under load.

If you do change the pump, take all the spark plugs out and turn the motor with a socket on the crank. Shine a flashlight in the spark plug hole of cylinder#1 and you will see the piston at TDC. Use the distributer and the timing marks to make sure that you are at the proper stroke.

Be sure to prime your oil pump before you put it on. Just fill it up as much as you can by pouring some oil in the holes (but not so much that it spills all over the place when you turn it at an angle to put it in).

See what Earl said about the distributer.

[DavidM]

Looking more and more like an issue with the sender or with the wiring. Started the car up this evening and got 42psi immediately at idle. I don't think the oil pump would have magically healed itself overnight.

Let it warm up and then reved it to 4500-5000. Got 50 psi or so at those RPMs. The gauge seemed to get stuck at 40-50 as it wouldn't go below 40 at idle even with the car at operating temp. The weird thing is that when I turned on my electric fan to keep the car cool it seemed to jar the gauge and it dropped to about 25psi at idle. Definitely something flaky going on. I'll replace the sender and check the wiring.

I'll bring the spare oil pump with me to the track just in case, but I'm going to chalk this up to electrical weirdness. Hopefully that's the case. Thanks for all the help. See you at the track.

David

[CCARVER]

Glad it looks like a simple fix David.
If you dont mind, run blocker for the ITA CRX we are bringing up.
I know how wide a 240 can be at times!
See you guys track side.
Carver

[DavidM]

I haven't driven since Labor day last year so I'm not expecting a whole lot. I'll likely be trying to keep up with that CRX. If I can run similar times as last time out and have somebody to race that would be a good weekend.

David

[CCARVER]

I haven't driven since Labor day last year so I'm not expecting a whole lot. I'll likely be trying to keep up with that CRX. If I can run similar times as last time out and have somebody to race that would be a good weekend.

David

Have you seen the run group counts.
You will have plenty of racing to do.

[DavidM]

I got the new sender in the car and it seemed to work - for a while. I put it in Saturday and cranked the car up to see what kind of pressures it would show. It was giving me 50 at idle and going all the way up to 75 or so at revs. This seemed like a good thing so I was happy. Then I shut the car off and the gauge read 10psi with the motor off. I'm like WTF? Does that mean all my readings are now 10 psi high? I had other things to do and stopped working on the car till Sunday morning.

Go out Sunday morning and the gauge still reads 10psi with the motor off. Even better, the gauge never moved when I started the motor and now reads 10psi all the time. Somewhat pissed at this point, I start trying to figure out what is going on. The gauge reads 80 with nothing connected and 0 when grounded, which is correct. I ran a new wire from the gauge to the sender and still got the same goofy readings. Tried grounding the body of the sender with the same results. I'm going to try a couple other things, but the only thing I can figure at this point is the new sender failed. Lovely. If I can't make it work then I'll leave the gauge disconnected since bad readings are worse than no readings.

The good news is that the car is completely ready to go except for the oil pressure gauge issue.

David

[rev_d21]

Newbie here and this is my first post. What brand gauge are you running? Are the connections clean and tight? And finally is the wiring green in any spots? I had some cheap-o crap Glowshift gauges that did what you are describing. I have since switched them out to VDO with new wiring and things have been much more reliable. I am running KA24e engines in 2 older Hardbody trucks.

[Matt93SE]

This is only a 4 year old post you bumped, do I would assume the problem has been solved by now.

[rev_d21]

I see there is a great welcoming committee here. Hello to you too!

Apparently the problem hasn't been fixed.
https://improvedtouring.com...ad.php?t=31974

Rev_d21 Moderator at Nicoclub.com

Have a nice day.

[Matt93SE]

Sorry bout that- been a rough week. 13hrs at work today and still counting. first one in, last one out, boss doesn't even care.

Anyway.. Welcome!
David's been through probably 25 engines since 2009, so this one is getting tired too.
Strange.. my KA24DE has about 140k miles on the ticker and I rev it to 7000 every shift. This engine has been in the car since 95k miles, and I quit street driving it at ~110k. so it's got 30k track miles on the thing. pressure gauge never says over 40psi, but the damn engine just won't die!

KAs don't get tired, they just ventilate when they've had enough...

[DavidM]

LOL. I think the motor is more pissed right now that I don't run it enough.

I replaced the old oil pressure gauge/sender and that fixed the original issue. I think the current one is ok. The quick oil temp drop I see when I turn the car off is due to oil draining out of the adapter where the temp sensor is located I think.

I'd prefer to catch any oiling issues early so that the motor doesn't get extra holes in it. Maybe I'm a little too sensitive.

Welcome to the forum rev_d21 (got a name?)

David

[rev_d21]

Thanks for the welcome. My name is Devin. I autocross and rallycross Nissan trucks with KA24e engines. A buddy and I were talking of transforming one of my trucks into a Pro-IT racer with hopes of getting the SVRA to open up a truck class like Coor's Racetruck Challenge trucks of the late 80's which is how I found this forum, just browsing for as much info as I can find. Sorry about bumping a 4 year old thread, I just like trying to help people when/if I can. I will start an introdution thread one of these days, don't want to thread-jack this one any more than I already have.

Nice to meet all of you.