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L28 blowing oil. Literally.


MidnightRider

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A case in point: My father's Alfa Romeo...

 

 

Oh Alfa Romeos....... my dad has one. The radiator cap popped off when my school had this senior parade thing. I thought I'd really blown something. My girlfriend and I were running back to this kid's house to grab water bottles, made it just in time before all the cars started moving. My dad fixed the car with a rubber band and paper clip once, and I fixed it with duct tape the other night.

 

Of course more permanent fixes were done later.

 

4tkfoy.jpg

Edited by MidnightRider
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With a typical worn L6 pump you should have been able to drive around all day at under ~3,000 RPM, since they seem to start at ~15 psi and don't hit high pressure until you get the RPM up quite a bit. Was a new pump was part of the rebuild?

 

You can take the regulator valve apart from the bottom of the pump, without removing it, if I read the picture in the FSM right. Big bolt, washer, spring, valve. Might be worth a look before you install the new pump.

 

Edit - there might be a few more parts in there - http://www.carpartsmanual.com/datsuns30/DatsunZIndex/Engine280Z/OilPump/tabid/1610/Default.aspx

Edited by NewZed
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Rebuilt engine with new super doopet racing pump springs? Stack of shims in there locking it up?

 

I'm with the last, this is easily checked without shotgunning a pump at it and possibly causing more issues. Sounds like the pump is fine... Why replace it?

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I'm with the last, this is easily checked without shotgunning a pump at it and possibly causing more issues. Sounds like the pump is fine... Why replace it?

 

 

Because I already bought a new one. I don't know where else the problem could be, it's not the gasket surface of the filter, and the check ball seems*** to be working OK...

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Not sure how to respond to that, you mean the check ball?

 

No, engine bearings only go in one way. There are tops and bottoms and tangs (Spelling?) on the bearings, they must be installed facing the proper direction, tang in the right place and the tops and bottoms in the right place. It is very easy to overlook, even knowing they need to go the right direction, which way you install the bearings. Both main and rod bearings are like this and MUST be installed properly otherwise it could cause issues. I don't think replacing the pump is a horrible idea, but don't trust stock gauges to really do the job right, they are old and worn and just shouldn't be trusted. Even new aftermarket gauges can be faulty or have issues.

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Just curious as to why you don't put a pan under the car, a new.... non-fram filter, start her up. Tighten it as much with your hand, don't be light on it, and then most importantly.... check the oil pressure gauge...?

 

If you drove for 30 minutes, didn't check the gauge so who knows what your oil pressure was, and got to the store without a rod knock or anything (obviously there was oil somewhere in there to prevent self destruction) then it doesn't sound as eventful as the other stories these guys are posting.

 

All I'm saying is start her up and check the gauge! It's old and.. well old, but it will tell you whether it's pegged past 90PSI or not. The best we can do is diagnose from what you report and relating occurrences. Your gauges will tell, you in most cases, far more than what we can, without us being there. I put a $5 MECHANICAL gauge in my 521 (doesn't have a gauge) and just for a reference, that blow off is set for 55-60PSI and it's the same pump used on all the other L engines.

 

Hopefully you didn't pickup and pay for that pump though just yet unless if what you have is used and what you bought was cheap. That relief valve is the great big nut on the pump. Should be right there on the bottom when you crawl under there.

 

If in fact your gauge says you're at a crazy high oil pressure, pop off that big nut and pull the spring out... if I remember correctly the ball comes out too. This way you don't change the entire pump and spend the money. Perhaps when you pop it off and take a gander at it, maybe spray some cleaner in there, you will free things up.

 

One thing to note: once again if and only if your gauge is reading stupendous oil pressure and the relief valve is the problem, we must think... the valve is only a ball and spring. What can happen to this setup? It could get stuck and not release... or the spring could break and then it releases to soon or all the time giving little oil pressure. Did you have the pump apart like you see in the picture below? If so, did you put adhesive to that gasket between the pump cap and the pump body? Do realize that the clearances between there are very small so you can create good oil pressure, and that is why that gasket is very thin like wax paper. Point is if you put too much adhesive (I don't you're even suppose to put any but sometimes I do) it will ooze out the sides and as you can imagine, it has potential to ooze into one of the holes thus clogging it.

 

If you're broke like me, what I would do in this situation if I was indeed over-pressurizing the system, is check the relief valve. Not relieving pressure for whatever reason? Go into parts bin and pull out another pump cap. If it's used and has scrapes where the rotor goes then pull the dowels with vise grips and sand the surface flat, getting rid of the scrapes. Make sure the rotor spins when you put the cap on. Install the pump back on. I say this because if it's a new pump, you may still have the old one. It's a very simple setup, as long as holes aren't clogged, springs aren't broken, and the clearance is correct, you can't really go wrong. This is why I have a hard time believing there is something wrong with the pump itself, as in like the rotor and body, and therefore doesn't need full replacing especially if it is already new.

 

 

Just for reference, I use to use Motorcraft Fl-1A on my Z. It's a big ass filter, probably holds 3/4 quart, so fill that baby up as much as you can before you put it on. Anything but Fram. :(

 

Red arrow points to relief valve nut. Pull that and the spring and ball should come out. Stick the tube from some carb clean back into that port as shown in the bottom left picture and spray, see if nasties come out.

103x4t0.jpg

Edited by josh817
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It is a very rare thing indeed when a properly installed filter and base gasket "blows out" without bulging the filter housing.

They mak an aluminium ring that makes the o-ring on the filter base "blowout proof", as well.

 

You have EXCESS oil pressure. That tells me the PUMP is pumping just fine. As Josh surmises, maybe a relief valve is doing something...but is the filter housing bulged? If not, with a PH8A, then it's installation.

 

As mentioned above, putting the bearings in can block galleries... But it should wreck in short order. It was running "fine" before as stated, sosomething is missing. Not in flow production (pump), but in flow restriction engine.

 

Assuming proper filter installation, that is..,

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Yeah the stock gauges suck, that's next on my list of things to replace. I don't trust them either.

 

Even my speedometer is like 10 mph off.

 

 

 

 

 

But back to the oil pump, since I have a new one I'm going to go ahead and replace it.*

I've unbolted the old one but I can't seem to get it past the sway bar, and tips/trick?

 

I tried jacking up the car from the front but that didn't seem to help much.

 

 

 

 

Edit:

*When I rebuilt the engine, I did not rebuild the pump.

Edited by MidnightRider
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It's described with pictures in the Engine Mechanical section of the FSM, page EM-25 if you use the 1978 FSM (a good clear copy with sections separated, from the http://www.xenons30.com/reference.html site).

 

In the Engine Lubrication section there are descriptions of taking apart and assembling the pump, checking the regulator valve, and measuring clearances.

 

Could you remove the bolt and pop the oil regulator valve on your old pump, while you have it out? See if it's stuck or clogged? It would be nice to know if that was the cause for your problem since the pump was apparently pumping plenty of oil. Honestly curious, not taking any pokes at your method.

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With a little help from my dad I got everything timed correctly and the car is running again. Oil pressure seems fine after I let a little oil out, functions normally even when driven hard. Just needs a little tune up and the distributor to get the horses running. Thanks y'all. I'll probably be back on here again after Christmas unless I post a thread about Z car's and reliability because my girlfriend's dad is CONVINCED that you can't take an old car and make it reliable. His friend who built cars for Jay Leno told him blah blah blah.

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If its not the turbo dizzy, then you can just as well put the oil pump spindle thing at any which way you like, twist the dizzy until the rotor engages. Bring the motor to TDC compression #1 (do this by bringing it to TDC and checking if the two from lobes on the cam are pointed up). At this point put your cap on. If the rotor is pointing at one of the prong things on the dizzy cap, make that #1 spark, and then of course go counter clockwise 1-5-3-6-2-4.

 

Here is the tricky bit, if the rotor is pointed somewhere between two prongs, you can either use the two adjustments on the dizzy or pull the spindle out and do it the right way like the FSM says... One adjustment on the dizzy is either an 8mm or 10mm hold down bolt, the other is.... I can't remember I think it's on the underside of the dizzy or something. You can adjust both on the car, I know that much. This helps if you're trying to get more advance but your rotor was pointing between two prongs, so you're not limited to how much you can twist the dizzy until you run out of slot on the hold down bolt.

 

Another trick if you can't get enough advance or have way too much is to rotate the plugs counter clockwise or clockwise.

 

For instance lets say the rotor is pointing this way on the cap at TDC compression #1, which one do I choose?:

i3upns.jpg

 

If I make red #1 then I have to twist the dizzy clock wise a lot to get the advance I want, because at this point it's way too retarded. You may be able to twist the dizzy a lot but maybe not as much as you would like.

eixdt.jpg

 

Maybe I can't adjust to get as much advance as I want. So in this instance, I can just as well make #1 the blue prong. I will be far advance, but perhaps it will be enough for me to retard the timing by twisting the dizzy counter clock wise

14mqlx5.jpg

 

That being said, my dizzy both on the Z and on my truck had two adjustment points. Do realize that with 6 cylinders (6 prongs) that means every 60º of rotor rotation is a spark. Point is that on my L4 truck motor, the rotor was stuck between two prongs and I wasn't able to adjust it all the way out by using just the top bolt with that goes into the slot with the little line on it to point to "adv" or "ret". However, by adjusting the second screw and then the slot, I was able to not only get the advance that I wanted but also the dizzy is jammed over to one side which limits how far I can go. So that long lost point I was getting at... 4 cylinder, the rotor rotates 90º between each spark, which means I had to be able to twist the dizzy a lot to get what I want and if I could do it on there, then one could surely do it on a 6 cylinder dizzy where they don't have to twist the dizzy around so much.

 

 

 

EDIT:

Here is a picture of my dizzy with the two adjustment points circled. First point rotates the dizzy housing on the plate, the second adjustment adjusts the plate to the pedestal. It's the second adjustment that is the 10mm bolt that you can see when looking into the engine bay. That's usually the one you twist to time the motor. The bottom 8mm bolt is the one you can see but should be there and will help you get more twist if needed.

20zvabp.jpg

 

Now this was my personal experience on the truck. The rotor pointed down to 7 o'clock instead of 11 or whatever it's suppose to be:

bij9dx.jpg

 

So I put the cap on and see which one I'm near. I circled the one I chose for #1, but I could have chosen the one over to the left, clock wise. This would make it extremely advance, and I would have to twist the dizzy counter clock wise to fix this. I was closer to the one I circled, and this allowed me to advance it to what I wanted.

1z56yc7.jpg

 

 

Edit again:

Two hours too late. :unsure:

Your vehicle is as reliable as the quality of parts and car you put into it... My Datsun's require small things... The biggest dump I had was after trying like I stole the damn thing for 3 years and a miscalculated down shift I blew 3rd gear syncro. Replaced a tranny in a night and was on the road again. $300; tranny, new tranny mount, shift lever, new shift lever bushings, right sized drive shaft, 2 quarts of oil, and one night of work. Where else do you get a tranny change for $300 in a night? Oh yah, my mom got owned with $2000 on a Honda Civic automatic tranny and a week without a car. :rolleyes: Then again, labor costs.

Edited by josh817
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