What was the solution ? how did it hold ? any input you can give me ?

Thanks !

 

I had to pull the engine and replace my oil pump. If you have the same symptoms I had than I'd advise you to quit driving and replace that pump asap!

 

What was the cause for the problem in the first place ?

 

Debris in the oil that was small enough to get through the oil pump pickup screen, but large enough to get wedged between the oil pump relief valve piston and the wall of its bore. It then forces the relief valve piston against its bore wall tightly enough to inhibit movement. The only fix is to remove the oil pan and disassemble and clean the valve bore or replace oil pump entirely. The amount of damage and wear will likely determine your path, but I would replace the pump because there is a great likelihood that that debris has also worn the pump housing to gear clearance.

 

FINALLY after two weeks, the car is back !

oil pump, water pump, rod bearings and engine mounts - all replaced !

The car runs great, oil pressure is back

about a 1000$ parts+work

I will post pix of the bad valve bore asap

 

This is the 1000$ bore...











What do you think ? heat ? age ? (203k km)
debris ?

Thanks !

 

Deep scoring indicates wear.

 

Is that normal wear ?

 

That looks very similar to mine. A piece of debris got between the relief piston and its bore on one side and wedged it against the bore on the other side. The lengthwise scoring is from the piston galling the wall of the bore as it opened and closed. Mine eventually dug in so much it seized in the open position and required significant force to remove.

The debris was on the opposite side from the score marks and may still be in the bore.

 

I doubt it. Sixshooter's reply may indicate what caused it.

I would hope that a decent shop would inspect the bore and clean out any crud before installing new parts.

 

Negative. The oil pump housing is garbage. When the steel part looks that bad, the aluminum bore it was contacting is three times worse. Housings are disposable.

 

Ah. Didn't realize the bore was aluminum, I assumed it was sleeved. You are absolutely correct. Should have a new part there, if that piston looks that bad. It's going to leak past it otherwise.

 

Mine was identical and as sixshooter said I had the same problems. Time for a new pump!

 

From what I heard its the weld beads on new oil pickups. If you get a new weld pickup make sure you tap it and knock anything loose that could get lodged in your motor! Other then that, sloppy machine house work happens all the time. There is nothing you can do to prevent it/fix it. If the debris is in there, sooner or later its going to find its way to your pickup.

 

+1. More complexity and expense for no gain.


The 89 Katana750 (I'd assume all the GSX- series motors from the time period) have the oil pick up tube held on by a bolt outside the tube on one side of the flange, and another on the INSIDE.

When this backs out, the bolt falls down and rests on the inside of the screen. At very high RPM's, the bolt is drawn into the pump, and the end of the bolt gets a nicely machined smooth round end on it. Very pretty. I assume the head was too large to get into the pump since that end was fine. Back off, sound goes away. Very odd thing to diagnose only with your ears.