Is this oil pump still usable?
 

I was tearing down some other engine components while I wait for the block and head to come back from the machine shop and I noticed this chunk missing from the oil pump. It doesn't look like it would be a big deal, but this engine has had oil problems so I just want to make sure.
https://cimg8.ibsrv.net/gimg/rennlis...a870c9b063.jpg

That's exactly why you had oil pressure problems. Look for a good used one. Note: two different pump drive sleeve and seal were used depending on the year of the pump.

What is exactly why....?

You see something from the picture to tell him that his pump is no good...?

If you are referring to the casting that looks exposed like it might have cracked on the crescent, that's normal.

You have to know a precise depth measurement of that pump body minus the thickness of the gears to judge condition of a positive displacement pump like this.


In most pumps of this type, you'd be checking wear in the inner face of the crescent too but the drive gear is located by the crankshaft and the inner gear teeth are too blunt to cause wear there.

OP - do you have the shop manual...?

Only thing I can see from the pic is that this pump was exposed to water.

T

BTW - OP, if you look at the aluminum casting, holding it in one hand and this cast pump body in the other, imagine them going together, you will note that the length of the smooth part of the crescent bridges the same distance on the aluminum housing.

If the part that's purposely removed (the rough part) were intact like the rest of the crescent it would partially block suction from the girdle passage.

T

Even if the depth minus thickness of the gears is a couple thousandths off, you can surface grind (top lip flange in picture) it back into spec.

This will leave you with a heavier mil thickness of the flange sealant though when installing onto block, not necessarily a good idea.

But yeah, assuming the clearance checks ok, all I see is water/rust staining on the gears themselves.

I would say that this happened when the engine was parked and not running at some point in it's life but there is evidence of water droplets in the cast pump body that he shows in the pic, down in the pocket on the right side.

While you are waiting, you can bead blast this whole pump and have the pocket and the gears coated with DLC or moly.

T

https://cimg6.ibsrv.net/gimg/rennlis...f66198a404.jpg

That's the drive gear area, the one with the external teeth.

The outer 5% of the teeth are bevelled and therefore never even touch that area you highlighted.

T

So where did that ridge come from?

Okay, I did not know that that was normal. And as for the water, yes this car had a severe head gasket leak. Is that enough to warrant a new pump or am I good with this?

When heavy metal particle failure occurs, you get impact damage, nicks, dings, drag scratches, etc. I don't see any of that here.
You need the manuals with the measurement specs and the means to measure it accurately to determine whether it is good, nobody can do that by viewing a picture.

To your original question, the open grain casting that looks like it is damaged, is normal factory crescent manufacture, nothing wrong there.

Post back if you need the gear and pocket depth specs, I'll dig this from the manual for you.

T

Sorry, don't see a ridge.

In the area you highlighted, all I see is reflection from wetted surface.

T

FYI, LensCraftersrafters are running a 40% sale.

I've got an oil pump in really good condition, $60 shipped if you need

Now you see...., I was going to let you slide.

The OP said he noticed a chunk missing out of the casting as the focal (pun intended) point of his concerns.

You rushed in to say "that's exactly why you had oil pressure problems".

Then after it's pointed out that this is a normal feature of these pumps, you come up with some imaginary defect that's impossible to determine from an internet jpeg and then blame somebody else for not being able to see your boogey man.

It's pretty obvious that you know next to nothing about this oil pump so why don't you just sit down.

T