Newly installed rocker arms fell off on initial start up...

[idosubaru]

130,000 miles, automatic, XT6 - couple (2 or 3) rocker arms on the drivers side fell off after running the first time for a few minutes.  it ran fine before the headgasket job.

 

were they simply not pumped up or is something else wrong?

 

i guess i'll install new HLA's in those positions that fell off - should i pay attention to or do anything else while I'm in there?

 

i never prime them, never seemed to make a difference - i've always started and let the oil pump prime them. could that be to blame?

Edited August 4, 2013 by grossgary

[NorthWet]

I can't imagine that the HLAs have enough stroke to allow the followers to fall off (I could well be mistaken).  I would be more inclined to believe that the valves hung open.  Did you just do the HGs, or did you also do some valve work?

Edited August 5, 2013 by NorthWet

[man on the moon]

When installing the rocker arms, I always use a small dab of vaseline on both ends. It holds them in place and insures they aren't shifting a wee bit when you jimmy the cam into place. Beyond that...the HLA shouldn't relax enough to allow that, and as long as the other end is positioned over the valve end properly you should be ok. Was it one HLA, or all of them?

[Crazyeights]

Over the 30 or so years that I have been building and installing engines I have seen this happen a few times (to me and other techs). There doesn't seem to be a concrete reason and it usually never happens again once fixed and re-started. This isn't Subaru specific though. Hopefully it didn't cause any damage.

Edited August 5, 2013 by Crazyeights

[Mark Humble]

Sticky valves. Lifters don't have enough travel to allow the followers to drop out.

 

Mark

[idosubaru]

Sticky valves. Lifters don't have enough travel to allow the followers to drop out.

seen this before on subaru's?  

they don't have enough room to squeeze them back in place now - so i guess they stuck right at start up, then freed up as i was running/trying to restart?

 

I Did you just do the HGs, or did you also do some valve work?

just headgaskets

 

W Was it one HLA, or all of them?

i think 3 of them. 

when assembly i greased them and made sure they were on before continuing.

 

OHopefully it didn't cause any damage.

non-interference and everything looks normal other than the arms slipping out.  thanks for the feedback that you've seen it before, that's slightly comforting.