1G Oil pump failure working on rebuild

[sytherstrike]

Had my oil pump fail with in 100 miles of a rebuild. Trying to figure out what is salvageable. Crank is being checked at a shop, I'm concerned with my pistons. The wear is the same on all, and there is no scoring. Dont know if this is normal or abnormal. Read that coating isnt supposed to come off others say its for breakin.

You must be logged in to view this image or video.

 

[T bags]

Those pistons don’t look so good. I’m guessing the cylinder walls have the same wear

 

[sytherstrike]

Those pistons don’t look so good. I’m guessing the cylinder walls have the same wear;

You must be logged in to view this image or video.

Cylinder doesn't look abnormal to me, it's a virgin block so if it comes down to it I will bore and go up a size. It feels smooth, can't put my fingernail into anything.

 

[1990TSIAWDTALON]

Had my oil pump fail with in 100 miles of a rebuild. Read that coating isnt supposed to come off others say its for breakin.

My coating was still on after 600 miles or so. It does wear off but mine don't wear off that fast. I have pulled apart motors with many more miles and they still have some coating. They are scuffed usually but after a lot of miles. Maybe some others can give some more opinion.

 

[DSMPT]

I don't know what kind of oil pump failure and how long you had driven with the bad pump, but that piston wear is probably apart from the oil pump failure.
Hard to tell by the pics but if you say there is no scoring at all on pistons and cylinder wall and if you don't catch anything with your fingernail, then my opinion would be PTW clearance was in loose side. This kind of wear pattern is seen on a loose built engine or a stroker engine.

 

[T bags]

Looks ok
Get the micrometer out and do some readings.

 

[Mech Addict]

Super bummer to have that happen on a fresh rebuild. I've been contemplating a rebuild on my original motor and this is the nightmare scenario. What did you find with the pump? What kind was it? How did you become aware of the failure vs. how far did you drive with no pressure?

 

[diambo4life]

A quick hone can salvage those cylinder walls. Check and make sure the concentricity "out of round" is within spec. If it's a beater...I would run it. I would still hone and toss in new rings. Cheap insurance.

 

[sytherstrike]

Thanks for the input, I ran it for about 2 or 3 miles cruzin at 55 before I relised I had no pressure. Clearance was on the loose side after the first build, going to take it all to my local machine shop and have them go over it.

 

[Mech Addict]

At least that fairly low rpm/ low cylinder pressure conditions. I'm hopeful that damage wasn't severe.
I'm really curious what the cause was. My WAG is something on the suction side came loose. Perhaps the pickup is lying in the pan. If it was drive sprocket or other pump internals I think all hell would have broke loose in a hurry.

 

[sytherstrike]

At least that fairly low rpm/ low cylinder pressure conditions. I'm hopeful that damage wasn't severe.
I'm really curious what the cause was. My WAG is something on the suction side came loose. Perhaps the pickup is lying in the pan. If it was drive sprocket or other pump internals I think all hell would have broke loose in a hurry.

I just ran out to my garage and pulled the oil pump apart to see what the problem was. The gear that rides on the timing belt turns hard and wobbles, and the gear inside the pump looks like it was chewing up the housing.

 

[Mech Addict]

At least it didn’t throw the belt in the process. Do you have a balance shaft eliminator installed?

 

[sytherstrike]

At least it didn’t throw the belt in the process. Do you have a balance shaft eliminator installed?

Yes

 

[Dericsh]

Yes

Oem stub shaft with oil groove?