Oil on plug. Chasing codes.
- Thread starter Jhkj04
- Start date
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derekj
Full Access Member
The missing rocker would keep the valve closed due to the valve spring pushing up on it - but chances are the valve being stuck open is what caused the rocker to fall off in the first place. In your picture the valve spring looks compressed which means it is more than likely bent or the spring is broken - can you compare the spring height to one of the other exhaust valves when it is closed - that will confirm that the valve is stuck open. And yes that will cause the rich code on bank 2 as raw fuel is going right into the exhaust before it can be properly burnt. Interesting that you didn't get any misfire codes for #6.
derekj
Full Access Member
You really need to determine why there is no compression on that cylinder before ordering more parts - you have to get to the root cause of the problem - just ordering random parts is not going to solve your problem and cost you more money in the long run. Just some advice from a long time licensed technician.
derekj
Full Access Member
were you able to compare the valve spring heights to confirm if it is stuck open?
Best I can measure they are the same. My best option I feel is to install a new lifter, new injector and pop the rocker back on then check compression praying it exists. Even if it’s other issues I can’t pull the head and it was running on 5 cylinders enough for what I plan to do with it getting me to next winter when I could pull heads or swap of for a donor motor.
With allot of looking it may1/8th lower than the next cylinder both with no cam pressing on the rocker. Could that be carbon build up holding it open? What are my odds a new lifter, injector and snapping the rocker on knocks the carbon off and she runs like a champ?
derekj
Full Access Member
It might work - you could also try pressing the valve up and down a bunch of times with a small pry bar before putting the rocker back in to see if you can get it to close all the way. Best way to check would be to remove the exhaust manifold and that way you could try and get in and clean the exhaust valve or see if it is bent, but that could be opening up another can of worms with broken exhaust studs etc.
turblediesel
memberable
Bent valve?
Feeling it may be or a lot of carbon and week spring. We know tonight I plan to swap the spring, valve seal and lifter while trying to free up the value with some sea foam once the old valve seal is out. fingers crossed
No luck, can’t get the valve spring out and now I’m thinking it may have dropped a valve seat that’s wedged holding the valve open. If I have to run it Asis until I get a set of heads is it better to unplug the coil and injector?
derekj
Full Access Member
shoot
dropped valve seat makes sense - probably just unplug both and see how it runs.
This seams to be the answer. I’m loosing faith anything else could keep the valve open like this. Also it makes sense why if the rocker fell off how it hung open rather than closed. Next question is new/used heads and gaskets or a full motor swap. Do we have any upgrades that swap in Easily?
Just a thought, if you are right about it dropping a valve seat, you don’t want to run it with possible metal debris in the cylinder. Scratching the cylinder wall up or punching a hole in the top of the piston would mean a whole new engine rather than just a new head. Can you get a look into the cylinder through the spark plug hole with your borescope to check for a dropped seat?
tried a bore scope lastnight but cant get the angle to see trying another one with a mirror tonight. what's a better move to swap heads and gaskets for 300-400 or swap a motor for 600-800? knowing it prob needs a torque converter soon. my goal was to just get it trailable for this year then swap torque converter or ****** and head gaskets next winter. be nice to get some time to watch for a deal and collect enough to redo the motor, trans, transfer then some gears and lockers.
derekj
Full Access Member
Only problem with a used motor is you are possibly getting one that could have a potential valve seat issue down the road - I would go with a good set of rebuilt heads.
True, thoughts on a set of used take off heads they claim are good to go. Found a set for 100$ plus shipping. I knew it needed a head gasket at some point so mine are toast and would need the dropped valve seal fixed the other trued or milled from the head gasket leak. Agree a new/used motor is what I have at some point.
Ok let’s talk turkey. If I pull the heads and cylinders look good can I bolt on a used set of heads and go? And the set I have was not taken care of properly so the dropped valve seat is on bad oil changes. I feel a reman set is into that used motor price. I found a motor complete for 800 then a wreck with a motor and trans for 1300.
