I was wondering that too.

 

You can take the sleeve and put in dry ice for awhile and then drop it into the block. Never had to warm the block itself, but it couldn't hurt. Use to do this all the time on early Mack engines. After the liner is installed take a stiff metal bar with two holes in it so you can use head bolt holes to use as a clamp to hold the liner down until it warms up.

 

Look at the back ground also. Nice shop work area.

 

Got to thinking about how to change the cylinder liners and found this. The instructions say don't freeze liner or warm block.
Live and learn.
http://www.crateenginedepot.com/pdfs...structions.pdf

 

Whoa! Glad you shared this! That would not be good, had I got into that job and freezed the liners.

 

If you are going to pull the intake to change the injector seals, consider doing a leakdown with the intake off. You will be able to hear if you are leaking past an injector seal or an intake valve that isn't sealing.

By the way do you have the EN-48266-1 & 2 tools for replacing the injector seals?

 

Great idea! I had actually already thought of doing this.

Yes!! Got it here. Just arrived in the mail yesterday. New seal kit is expected to arrive today in the mail. The seal tool is not genuine Kent Moore, but they claim it's identical sizing though. And since it was a few bucks cheaper, I nabbed it. Ouch though, not really a cheap tool, but I suspect it may come in handy a few times.

 

Good, just wanted to make sure you have the correct tools at hand. Yea, Kent Moore is very proud of the tools the sell. I have drawing of them and at some point wanted to have them made. My guess is that any DI engine manufacture has to have a similar tool to install the new seals.

 

The verdict is in. I spent the lion's share of the weekend, very carefully diagnosing P0304 and I think the conclusion is clear and undeniable. The problem lies upstairs (valves), not downstairs (rings).

First, I did another compression test. Here were the results:
Dry...
#1 160psi
#2 155psi
#3 160psi
#4 105psi

Wet...
#1 175psi
#2 190psi
#3 195psi
#4 150psi

Here are my thoughts and conclusions on the compression test...The results vary some from the test last week. The dry test was "in the ballpark" from last week, but the wet test was a little lower. And I believe this is because I was a little too liberal with the oil during the first test, thus elevating the results. This time around, I didn't put so much oil in each cylinder. I still believe all 4 rings are showing wear, but fairly equal, again due to the nearly equal jump in pressure for all cylinders from dry to wet. I do not believe any rings are shot, necessitating an engine replacement. I believe there is life still in them and now have no intentions of digging in to replace/repair pistons or rings.

I then moved on to tear off the intake manifold and found the culprit. The pictures below show heavy coking on the valves of all four cylinders.









I then moved on to perform a very careful leakdown test on all 4 cylinders. Note, @DrLoch mentioned checking the injector seals during the leakdown test. I wanted to do this, but was unable. You simply cannot gain access or visibility to the seals while the injector rail is installed. So I scratched that aspect. Nevertheless, I brought each cylinder to top dead center and pressurized them. I carefully looked for leakage at the intake runners, exhaust pipe, oil fill cap, and PCV port in the head (the latter two checking for piston ring seal). I then rotated the crank 360° to move the cams to the other part of the combustion cycle, just to rule out any possibility that I missed the sweet spot (i.e., TDC) on a given cylinder. Once checking #4, the answer was obvious. It was undeniably leaking like a sieve through the intake valves (see the attached video) due to heavy coking. No other cylinder even came close to this amount of intake leakage; in fact the other 3 cylinders had reasonable intake valve sealing. None showed any significant leakage through the PCV port or oil cap (i.e., piston rings are all in reasonable shape with sufficient seal). None showed any significant leakage through the exhaust pipe. To be doubly sure on #4, I ran the test several more times and with the help of an assistant, I rotated the crank slightly fore/aft TDC to ensure I didn't inadvertently miss the sweet spot. No dice, the #4 intake valves never sealed up.

Because I want to be completely sure, I proceeded to tear off the injector rail to inspect the injectors (pics below). I concluded that all 4 injectors are in reasonable shape. With a little carb cleaner, they all cleaned up nicely and I gently probed each pinhole with my wife's sewing needle to ***** out any specks of debris. I installed new seals and swapped #4 with #2. The swap was so I could drive the car a few days and see if the code moved to #2, thus indicating a bad injector. Note that I highly doubt the code will move based on the definitive results of the leakdown test, but I went this far into the troubleshooting, and didn't want to shortcut at this stage of the game.





So in conclusion, I see no issue with the piston rings that require immediate attention. Although, we can all agree that they do show some wear, but I believe it's fairly equal wear on all 4. I put everything back together and drove it for a test drive. No issues. It drove like normal, as it has been. That is, it runs like a champ when warm. The misfire only occurs on cold startup.

I will drive the car a few days and look for the CEL to reset. I believe it will reset to #4. As such, my next plan is to walnut blast the intake valves and I believe this will rectify the situation completely, restoring the engine to a nice, running condition. I will also install a catch-can on the line going to the turbo, as well as the PCV port in the intake. Hopefully, this will alleviate the need for a future walnut blast.

I will report back after I complete the walnut blast to give the final verdict.