I had the same thing happen on my na 1.6 in my westy way back in 93. It was the press relief valve in the oil pump.

My memory is hazy on this, but I think the galley that the piston and spring reside in the pump is capped with a pressed in plug. It might be better to get a new pump body.

Alistair

> On Jun 17, 2015, at 7:39 AM, Frank Lee <techedteacher@GMAIL.COM> wrote:
> 
> After complete rebuild including new OHC head, rings, bearings, injector
> rebuild, new oil pump...  Now on warming up oil pressure peaks and blows
> out the big Mann oil filter, spewing out the oil.  Something about oil pump
> check valve or bypass?
> Does anyone have direct experience with this issue?
> 
> 
> 
> --
> Frank Lee from Gmail Mobile