highlander

I see that all the Subaru Specialists are selling "modified" oil pumps but none of them detail what the modification is.

Does anyone know what the modification is and is it simple to do on an existing OEM oil pump if you already have a new one of them?

briforbes

It's believed there is a fault with the design of the original pumps, whereby the piston doesn't get enough lubrication and siezes. That's what caused my engine to fail, and the rebuilt engine now has one of the modified pumps to stop it happening in the future.

Not sure how you would modify the one you've got, but I'm sure someone will be along in a bt to explain it better...

highlander

btt

anyone know how easy/difficult to modify an oil pump

stevebt

iTrader: (8)

the mod is on the "oil pressure relief valve" its a piston which controlls the pressure and if there is any breakup in the engine such as small particles of metal. this can block this valve resulting in the engine being starved of oil and ruining the engine, an oil pressure guage will help to avoid driving with this fault !!! it is really common on a lot of cars an i have ruined 2 vauxhall engine with the same thing both cav 4x4 turbo engines

ZEN Performance

The standard valve piston can stick, but the bore the pump slides in isn't great either. If you have a well used pump with a "bedded in" bore on the releif valve, I would be inclined to keep it. Many people point to the pump as being the failure, when in fact a bearing failure introduces debris into the valve that makes it seize after the original failure.

Paul