97 EJ25 block/95EJ22 heads/delta cams/Cometic hybrid gaskets

 

I have been running my frankenmotor for about 2 weeks and it rapidly developed a noise after sounding great.  It is not piston slap.  I had that on my Outback.  This is not a constant noise.  Most of the time the motor sounds great.  Then a tapping noise comes in and can go just as fast.  Cold or Hot doesn't affect it.  Sounds like something is loose inside the block near the head gasket on the pass side #2 and #4(BB half).  It's not banging, but kind of tapping with no reverb.  But can change in volume as well.  It doesn't sound like rod knock to me because that usually gets louder with rpm and this is usually only at idle, ocassionally.  I'm thinking a loose wrist pin.  Not sure what else it could be.  I'm going to go pull the oil and check it, but any thoughts are greatly appreciated.  I'm scared to make a video bc I don't want to waste the block.  I Iiterally sold my backup EJ25 block a couple minutes before I figured out this one is in trouble. DTOH!

 

Another question is "Can I reuse my Cometic HGs after they've been on there for a couple weeks and maybe 400 miles?"

Oh yeah, and all the timing stuff checked out.

Do you think you used the Ej22 wrist pin in the Ej25 piston?  If so you should be able to pull the clip, drive or pull the pin and do the swap without splitting anything.  Its just a matter of taking the engine out.

95 heads would have hydraulic lash adjusters which are known to make some noise, and they will fade in and out while running.

 

You can check lash adjusters with a prybar when the valves are closed. Just use the prybar to push against the rocker arm. If the lash adjuster squishes its bled out. A half bottle of MMO in the oil can clean out the ball valves in the adjusters and keep them from bleeding out.

Wait until the ticking starts then turn off the engine and check for play in the lash adjusters. If its not making noise they will be pumped up and there will be no "squish".

 

You could also swap to solid lash adjusters by swapping in whole rocker assemblies from a 97-98 2.2.

Edited July 19, 201312 yr by Fairtax4me

Wow!  Thanks for the quick responses guys.  I dropped the oil and it looked good.  And then I found the cam sprocket on that side lacking torque.  DTOH!  Tightened it up and put oil back in it and no more EXTRA noise.  Back to just good ol' piston slap for me.   On to OBX equal length headers and catback and then it all goes in my XT.     At the moment, it's in a 95 Impreza for test purposes.