EGR valve VX

[kais3r]

I've had a look and it appears that the suspect cylinder has an exhaust valve rocker and spring position that's off centre on the valve port, (too far left towards the firewall), the rest look straighter and more centred, but the exhaust valve spring on cylinder 6 also has the same problem just not as bad, and the spark plugs I checked showed lots of carbon on plug 2, clean on plug 4 and half dirty on plug 6, so there's a pattern there.

If these lifters aren't lined up fairly centre, could this be the potential problem and allowing the valve to leak pressure in the cylinder?

 

[dirty hands]

not the heads of valves

 

[kais3r]

Some pics.

First pic is cylinder 2 alignment overview
Second pic is showing right side exhaust valve spacing (left valve)
Third shows left side exhaust valve spacing
Fourth shows cylinder 4 (good cylinder) alignment as comparison

Thoughts?

 

[kais3r]

If those rockers are off centre, could it cause the valve to not sit flush on it's seat or even wear out the valve pin shaft housing?

 

[dirty hands]

first I see a very clean engine .for km..well done

 

[kais3r]

Thanks lol, mobil 1 5w-30 full synthetic keeps it that way, although it's due now for an oil change hence the darkened oil.

It's possible that the alignments are how they're supposed to be, I noticed the rocker pins go between cutouts on the bridge and would make it be that way, so likely all good there.

Just need to know what's causing the low compression in No2 vs the others.
Could it be dirty valve seat?

Would a few rounds of seafoam be a worthwhile treatment to clear out any crap inside the cylinder?
Let it soak and pump out by cranking only...

Is a bit odd that it's just the one, the rest are all very even pressure.

 

[dirty hands]

my advice is do nothing to the engine till it gets much worse

 

[kais3r]

Didn't remove that fuse but did ensure the spark plugs and injectors wouldn't run during cranking.

Didn't do WOT either as I was just comparing between cylinders, not seeing if they were all in spec, as I'm chasing a rough idle issue.

Without WOT to remove the vacuum, plus running temp, the cylinders were all 175psi and 120 on the bad one.
Also when engine was about 50deg they were all 195psi vs 160 on the bad one. So when hot the difference just exceeds the 70% rule.

 

[dirty hands]

not the heads of valves

 

[kais3r]

Does the excessive carbon on the spark plug determine which valve it could be?