Wednesday, January 10, 2018

Project Subaru

 Hey Lady, I thinks I found yer problem. Its right 'ere.

 That's what I told my wife when she came out to the garage to see how project Subaru was coming along. You may recall last November that the timing belt broke and I needed to investigate how much damage occurred on this interference engine. It took the better part of an afternoon to remove the battery, drain the coolant and then remove the intake and front of the engine to get one of the heads off. The process was pretty straight forward and actually only involved a few tools. Ten, 12 and 14 mm sockets, a screw driver and a pliers were all that was needed.

 I threw all the removed parts in the back of the car not knowing if I would need them later or if I was just making it easier on the scrap man to haul it all away.

 So basically if you've ever removed a cylinder head from an Outback while the motor was still bolted in, well then you deserve a medal or something. I was able to unbolt and remove the heads without loosening the motor mounts and jacking the engine although I will have that extra step during reassembly because a torque wrench just won't fit between the frame and head. When I inspected the pistons I expected to see a few dings where the valves hit them and thats exactly what I found. Both pistons on that side appear to hit TDC at the same height, meaning I think that the rods weren't bent during the collision of the valves and pistons when the timing belt broke. What I didn't expect to see was a cross hatching pattern still present in the cylinder wall. At over 220,000 miles that doesn't seem right. This triggered some memories from when we bought the car and I seem to recall some discussion of a motor overhaul. Not really sure, my memory is all over the place on this one but I'm happy for now to think I can salvage the short block without that extra expense.
 The heads have all the exhaust valves visually bent. Not sure about the intakes but they did have what looked like signs of contact with the pistons. Not sure about any cracked valve guides but the heads are at the machine shop now. I'll report again when I know more.



  1. Bent valves are better than bent rods. Just out of curiosity, if the rods were damaged would they more likely twist or bend?

  2. Actually, now that I've done a little bit of research, I think the piston would crack first. In all the claims of bent rods that I've seen, no pics.