[metalrocker]

Hello to all, you may remember me by my famous stubborn thread - Poor Acceleration


First of all, I want to apologize for such inappropriate comments or behavior to all of you last two years..and I remembered all of you have advised me to do compression & wet test..

So...symptoms for this situation: Constant misfire in Cylinder 'One' and Random misfire in all cylinders. (Although replaced spark plugs and 92,000 miles on K20Z1)

Today, I decided to do compression test and,

Compression test results received from first cylinder to last cylinder:

Received PSI

1) 50 psi
2) 125 psi
3) 125 psi
4) 125 psi

Thanks for reading

 

[metalrocker]

Update Wet Compression Test *Warmed Engine*

DRY results :
1) 50 psi
2) 115 psi
3) 125 psi
4) 125 psi

WET results (added squirted oil)
1) 60 psi
2) 130 psi
3) 130 psi
4) 130 psi

Could that conclude that valves need some work or . . .should I do cylinder leakage test to find accurate leakage ?

Thanks.

 

[sharpsicle]

If you have access to a leak down kit, definitely do it. It's a powerful diagnostic tool that will tell you where to look next before doing any serious work. It could potentially be a combination of valves and rings, but even if it's just valves you'll be able to localize whether it's intake or exhaust before you get started.

 

[metalrocker]

Update ! JULY 2015

UPDATE:


Did valve cover removed & performed cylinder leakage test in cylinder one (that one has 50psi & misfiring)

Problem found: Exhaust valves leaking & problem confirmed that valves has been adjusted properly to specs..
Still misfiring in cylinder one & only solution to this is cylinder head replacement.. due to burnt valve seating and port

Exhaust valve replacement may help but not as much likewise a new head will.. :rest:

 

[Hyoriu]

Good thing its only the top end! Still must be a pain in the ass to work with :X

 

[metalrocker]

Update - October 2015

Update


Found another major issue, timing chains rattling @ 103,000 miles


Jeez..


Anyone got same problem?

 

[daje00]

Well just do that while you have the head off, it seems like the perfect time for you find that out.

 

[revilingfool]

could just be the tensioner. chains rattle when tensioners go bad. might not be a bad idea to replace chain if already in there.

 

[metalrocker]

Attention!

Cylinder #1Captured picture today of valves (exhaust valves) at compression stroke and....it's 50psi of compression right there so...

I got borescope with mirrored tip at the end

Drums roll, please


Exhaust got bent and eventually burned (bent happens first. Burned = misfiring at a year later)


So, exhaust valves are bent and burned.


This December, I will be replacing valves and a timing chain kit with other timing components and new set of gaskets


Why? Misshifted from 4th into 3rd gear and high revved past VTEC then VTEC lobes on camshafts touched piston violently, so...exhaust valves got bad, in that case, stretched chains as well, causing chains rattling

This can happen in two situations either: valves get fu**led up and chains intact. Or, chains gets rattling and some harm to valves so.. it all make sense

My FAULT.