Rebuild?

[Kansei240sx]

PLEASE READ THE WHOLE THING BEFORE YOU POST. I need as much accurate info as possible.

RB25DET S1

I have a few questions.

I know how to run a catch can, and all that jazz through the previous thread.

Earlier this week, i noticed a rough idle in the engine so i pressure tested the intercooler pipes. I found several leaks and fixed them, and i also noticed that the PCV valve was letting pressure into the valve covers and coming out my catch can lines.

So i removed the PCV hose, capped it off and blocked the valve cover off with a tight rubber fitting. While i was looking at all of this, i noticed a great amount of moisture built up into the hoses running from the covers to the tank. I've never seen much moisture period in the lines period untill recently.

I live in oklahoma and right now its cold as hell outside. The car is garaged at night so the coldest it see is above freezing during the night, but is exposed to it later in the morning after i go to work.

I pulled the top of the catch can off to find at least 3/8 of a cup of water in there just below the return line on the can to the intake.

There was also a milky white oil/goop mixture on the fittings and a few other places.

I cleaned it all out and it idled perfectly fine and stays solid at 800 rpms and drives fine under load.

I did a compressoin check tonight, now the FSM says at 300 rpms, the standard value is 12.5 bar which is around 175 psi, and the limit is 9.5 bar which is around 125 psi or so.

I have an RB20 starter and an RB20 9.5 lb flywheel on an RB25DET so it cranks notably faster than it did when it was stock with all the spark plugs out. Before and after the flywheel was installed, so i can imagine that its going a bit faster than 300 rpms but not by much if any, i dont know, but im sure that doesnt effect the compression reading much.

::edit::One thing i did not do, was release the fuel pressure, and open the throttle body completely::edit:: The engine was at operating temp when i did the test though. Cylinder 1 127Cylinder 2 127Cylinder 3 129Cylinder 4 129Cylinder 5 127Cylinder 6 130

With it running just the same as it always has, making around 272 rwhp on around 12 psi with an 11.3 afr, and 15 degrees of timing, i cant possibly see needing a rebuild, but i might also have a gauge that reads low. With the difference between all cylinders being pretty slim i think that it might be ok.

Now i understand that moisture collects in these things, im getting a different catch can, and running one that is baffled, and put the feed line in the bottom and the return line to the intake hose before the turbo.

Here are some pictures of the moisture.

There was also some moisture on the dipstick as well.



All i really want to know is if everything is normal, because im a paranoid S.O.B. when it comes to this engine.

[BoostFab]

I pulled the top of the catch can off to find at least 3/8 of a cup of water in there just below the return line on the can to the intake.

There was also a milky white oil/goop mixture on the fittings and a few other places.

dude, don't worry about it, it's normal to see oil and water in the catch can. it is normal from condensation, slightly more during winter because air is more dense. when oil is in gas/vapor stage, when it is cooled down and collected in the catch can, you will see water. it's like you see water coming out of the exhaust pipes. mine was like that too.

[l0nestar]

Which catch can is that? I like...

[BoostFab]

Which catch can is that? I like...

greddy or look a like.

[240z4u]

Its super cold here and I have the same thing happen. I wouldn't worry about it.

Evan

[Kansei240sx]

Ok, its a megan can. Thanks for the reply guys.

What would you all say about the compression, i talked to a few other friends of mine, and since the compression is very close together, they said maybe try a different gauge. I think those numbers are a bit low, but for how close those are together im not worried to much about it, im probably pretty sure those numbers would be higher if i re-did it again after running the motor for longer and reaching about 90 degrees centigrade.

[240z4u]

Your numbers are close enough together where I doubt there are any problems.

Evan

[Darius]

Actually this thread makes me feel really good. Why?

I was getting some moisture in my catch can this summer and fall in the cool weather. Several other people have seen this same thing happen, so don't worry about it. It is normal.

If you are seeing that moisture in your crank case, then it would make sense for the oil inside the block/head to show some signs of moisture. (i.e. slightly milky). I bet if you get it out and run it for an extended time period at operating temp, the water will evaporate out of the oil and will probably condense in your cool catch tank making an ugly mess in there instead of in your oil pan.

And I wouldn't worry about the compression numbers, it is cold out and compression is only good for comparing cylinder pressures to see if there is a major issue. Leak down testing will tell you more about a condition.

[BoostFab]

Ok, its a megan can. Thanks for the reply guys.

What would you all say about the compression, i talked to a few other friends of mine, and since the compression is very close together, they said maybe try a different gauge. I think those numbers are a bit low, but for how close those are together im not worried to much about it, im probably pretty sure those numbers would be higher if i re-did it again after running the motor for longer and reaching about 90 degrees centigrade.

did you do the compression on the motor that has brought up to operating temperature or on a cold motor ? you should always do compression test on a warm motor with throttle wide open to get more accurate result.

[Kansei240sx]

I appreciate the help as always guys. Im going to fire it up tonight and replace a few gaskets i need to and give it a go.