Oil pump resistance paranoia

[1fast97gsx]

My last motor seized due to a seized oil pump. I pulled it, parted it out, and bought an ams bottom end off of a local NABR member. I'm finally ready to throw the timing belt on it and drop it in the car when I go to prime the oiling system with a drill for added safety and notice the pulley has slight resistance at some point. I was trying to turn it with my hand and it will turn smooth as can be and VERY easily turn for about 3/4 of a turn, then you feel some resistance for 1/4 turn and then all the sudden you feel it get really easy to turn again. The bottom end was fully assembled still when I bought it when an evo oil pump that was brand new at the time of assembly and has about 6000 miles on it now. Should I be worried by feeling this slight change in resistance or could that be normal just from sitting for a few months? I put 4 qts of oil in it and spun it for about 45 seconds to a minute and it still feels the same.

 

[AMS Eric #2]

Do you know if this motor has a stub shaft or a turned down full balance shaft? I would probibly remove the oil pump and check the gears to be on the safe side.

 

[1fast97gsx]

I appreciate your quick response. It has the turned full shaft that looks like this: clicky

 

[DsMWookie]

Is it an aftermarket oil pump or a brand new one from Mitsubishi?

If its an aftermarket pump check to make sure some of the casting isn't just barely tagging the gear. If it is just sand it off and assemble it. I have a ROCK oil pump and it had a little cast imperfection and I smoothed the spot very gently and the pump has worked wonderfully.

 

[1fast97gsx]

From the reciept it says its an oem evo pump I believe. I'm assuming at ams they use only oem stuff?

 

[Mike1992]

Is it an aftermarket oil pump or a brand new one from Mitsubishi?

If its an aftermarket pump check to make sure some of the casting isn't just barely tagging the gear. If it is just sand it off and assemble it. I have a ROCK oil pump and it had a little cast imperfection and I smoothed the spot very gently and the pump has worked wonderfully.

I had this exact problem with my ITM oil pump, I had to file alot, in tern I filed to much and ####ed that oil pump up. Now I'm running an old OEM with the new gears in it.