My 1996 Outback blew a head gasket so i decided to take on the project by myself.  I'm at the camshaft install stage of the reassembly and noticed that when i try to turn the exhaust cams by hand it takes very little effort.  But the intake cams require 2 hands to turn.  As a test, I installed the intake cams without the lifters and it was easy to turn.   I thought maybe it needs a valve adjustment as some subarus do, except mine is the one with the zero lash hydraulic lifters (no shims, no adjustments).  Has anyone ever experienced this?

 

Prod. Date - 02/96

Cid - 2.5ltr DOHC

 

Do you mean drivers vs. passenger side?

 

The position where the cams line up the Drivers side cams will be loaded.....this is normal.

The driver's & passenger's side each have 2 cams one on top of the other.  The bottom cams are the exhaust, the top ones are the intakes.  I also removed the lifters and squeezed them with a clamp to relieve the oil and get more space between the lifters and the cam.  No luck there either.  At this point i am wondering if the machine shop cut the valve height evenly on all the valves to compensate for the angle cuts that were done during the valve job.  If they didn't, then the valve stems are too long and are being pushed open by the camshafts as i tighten the bolts. 

you're certain the crank is at the TB installation mark and NOT TDC?

Texan,  The timing belt has not been installed yet.  I performed a cylinder leak-down test and found out that with the cylinder compressed with air the gauge shows very little leakage (less than 10%).  When i start tightening the camshaft caps the cylinder decompresses through the intake valves which must be opening.  My suspicions are confirmed.  The machine shop messed up.  

Thanks all.

If you have a fine file you can file the stems down to correct that. It does take some time though, and has to be done perfectly flat.

I adjust the valve by putting them on my valve grinder also make sure the caps are in the right spots. They are labeled by cly # and a in or ex mark

Thanks Fairtax & Ivans.  I would much rather have the machine shop fix the mess-up.  Luckily, i discovered the issue just after torquing the heads down.  So no major teardown involved.  The only thing is, the head gaskets now have to be replaced since i torqued them down.  

Problem fixed!  No need to tear down the heads.  As suggested by a local mechanic, i loaded the lifters by turning the cams to where the valves are open and let it sit in that position for a few minutes.  Then like magic, the cylinders held pressure.  So basically the lifters did not bleed out properly with the C-clamp method i used. They needed to squeeze out the oil slowly.  Thanks all for the suggestions.

so, the adjusters were just pumped-up too far?

 

I would never have thought of that.

 

at least, no teardown required.

 

today I learned something

Ohhh, this is one of those weird 25D heads with the hydraulic lifters instead of shims. Wasn't thinking about that before.

 

I always install hydro lifters empty and let the engine pump them up.

All done.  The OB is running quiet and cool.  I learned a few things about Subaru's in the past couple of weeks.  

 

1. Have the right tools available before starting to take the engine apart (camshaft sprocket hold down and harmonic balancer tools).  Loosen the bolts before taking       off the timing belt.  It will reduce the risk of bending valves if one of them slips while breaking it loose.

2. Compress the lifter if they are hydraulic to avoid problems with valves staying open. Bench assemble if necessary and check the gap with feeler gauge before 

    putting the heads on the block.

3. The arrow on the crank sprocket is not the one to line up the timing marks when installing the timing belt.  Use the other mark (notch) behind the sprocket.

 

 

Thanks all for the help.