Checking Stock oil pump

[JordanZ28]

Dear all
I just removed the oil pump and take it apart after a blown head gasket , I looked online to a way to check it but can't find anything , here is the picture of the pump if someone can point anything , as I live in Jordan the shipping cost is a nightmare , I don't want to cut cost but if the pump is ok it will be great news.

 

[sandlapper]

Hard to say with certainty after only a couple pics, but it seems I'm seeing some scarring on a tooth and what seems to be lotsa wear on end plate.

Pumps are relatively cheap; not something to skimp out or be cheap on.

Suggest an upgrade but NOT to hi-volume NOR hi-pressure.

GM changed sbc pump design beginning mid-80s thru early 90s to a pump with (instead of M55 with 5/8" OD tube) --- to a larger diameter (3/4") inlet. That Melling pump part number is M155. Suggest YOU message Melling and ask them which pickup tube part number fits M155 and Also fits YOUR oil pan; they KNOW, just ask. The larger tube helps low to mid-RPM pump pressure stability --- that's where you spend most of your time. The larger inlet-tube diameter makes it easier for the pump to feed itself. M155 has both standard volume and standard pressure, but has a larger inlet.

 

[Bobs RPO Z/28]

Also make sure new pump pickup is spaced proper distance from bottom of oil pan. Too close it cavitates, I placed one too close once and could not figure out why I'd loose oil pressure so I pulled the motor out again and an old timer asked how close the pickup screen as the the pan.

 

[tom3]

If a new pump is out of the question at your location I would at least take the plate to a machine shop and have it machined flat. This would help reduce slippage and improve capacity. The pressure bypass spring can be checked with an air hose and regulator. But the pump is a critical piece, new is better.

 

[JordanZ28]

Hard to say with certainty after only a couple pics, but it seems I'm seeing some scarring on a tooth and what seems to be lotsa wear on end plate.

Pumps are relatively cheap; not something to skimp out or be cheap on.

Suggest an upgrade but NOT to hi-volume NOR hi-pressure.

GM changed sbc pump design beginning mid-80s thru early 90s to a pump with (instead of M55 with 5/8" OD tube) --- to a larger diameter (3/4") inlet. That Melling pump part number is M155. Suggest YOU message Melling and ask them which pickup tube part number fits M155 and Also fits YOUR oil pan; they KNOW, just ask. The larger tube helps low to mid-RPM pump pressure stability --- that's where you spend most of your time. The larger inlet-tube diameter makes it easier for the pump to feed itself. M155 has both standard volume and standard pressure, but has a larger inlet.

Thanks for replaying, my car is 78 z28 with stock engine and trans , I looked to the M155. Is this will fit my engine and pan without modification.

 

[COPO]

Common Symptoms

1. Low Oil Pressure Light. Engines are designed with an oil pressure monitoring system that is designed to monitor the oil pressure of the running engine and warn the driver if the pressure is too low for optimal engine operation. ...
2. Increased Engine Temperature. ...
3. Noise from the Valve Train. ...
4. A Noisy Oil Pump.

 

[sandlapper]

Thanks for replaying, my car is 78 z28 with stock engine and trans , I looked to the M155. Is this will fit my engine and pan without modification.

yes M155 will fit IF you choose the correct pickup tube. As I wrote, YOU ask Melling which tube fits both M155 and YOUR pan. Quite simple, really.