Valve clatter when warm - fresh rebuild EJ25 SOHC
I set the valves cold per manual (1mm IIRC) [edit - 0.20mm intake 0.25 exhaust]

Cold quiet, 85f coolant right starts clattering, by 105f the left starts clattering. Shockingly clanky.

Theories?

What else to check other than rechecking the valves? They are a pita to get to.

 

?? was clearances did you set the valves to as they definately are NOT 1mm ???

depends on exact age of vehicle but min. requirement is 0.2mm on inlets and 0.25mm on exhausts......later cars require slightly more exhaust clearance

 

From US manuals

EJ25 SOHC



EJ25 DOTC

 

Sorry for the confusion, should have been more accurate. Set them to the factory spec of 0.20 on the intake and 0.25 on the exhaust. It is a EJ 25 SOHC.

(Must have been thinking/remembering that .01 inch spec)

So back to the original question - clacking when warm....I figured with a fresh rebuild if anything the clearances would get tighter as the valves seated. This condition where they're quiet when cold and then start clacking as they warm is baffling to me.

Any ideas?

 

if those clearances are correct then that isn't the cause of any noise so would be looking at other potential issues including possibly even a dislodge shim??

 

Can you please identify what is be looking at?

The machine shop assembled the heads and I checked at the bolts for factory specs when I adjusted the valves. I don't remember seeing in the heads and I don't remember seeing in the schematic any shims.

 

what age & model car exactly do you have??

 

Engine from a 2004 Forester.

And curious - are there any EJ25s that use shims?

 

DOHC versions do.........

think your SOHC engine may use a 'screw & locknut" rocker arm set-up

 

Thanks for the insight in the DOHC.

Yes, my SOHC has the screw and lock nut adjusters.

 

SOLVED

Turns out the spacer bolts were loose. You can see them between the intake valves. It is clever (or lucky) that the valve covers are designed so the bolts don't fall out if they get loose. That would cause all sorts of damage. I'm grateful for that design feature.



The spec is 5Nm 3.6 FtLbs so very little. Upon sharing with a friend they reported they had two engines come back from a rebuilder that did the same thing.

At that low torque value they might have vibrated loose. I reinstalled with loctite. I did degrease the bolts and receiving threads with brake clean. I also (likely) tightened them to more than 5Nm since I don't have a wrench that reads that low and I didn't want them to get loose again.... Tighter is better, right?



It is possible I missed the torque process since it's buried in the procedure and I was, maybe without realizing it, relying on the heads being assembled by the machine shop.



It is also possible it was missed because the attention grabbing image does not have those bolts in the tightening sequence.

 

Lucky

 

Reminds me of my £200 Nissan Sunny; Some rocker shaft bolts kept vibrating loose. First few times it happened I didn't notice, it just clattered like loose tappets so just readjusted the tappets (10minute job and it was a doddle to work on), which fixed it for a short while but kept happening and got worse until it dropped down to two cylinders as the shaft backed further and further away from the cam at the one end so was losing valve lift. Wasn't visibly noticeable due to the position and springs holding it under tension until it became obviously sloppy when I grabbed it.

Came loose three times over a few years despite torquing and thread lock (blue thread lock, probably should have used red), last time I made locking tab washers on the bolts heads. That sorted it.