So, ive encountered my FIRST RB problem

[MeanGreenS13]

I just completed a leakdown test on my new RB20DET that i picked up this past weekend... the people i bought it from in miami say they pull it out of a running car so that gives me a little hope... 1 thorough 4 read almost NO leakage... but 5 and 6 read in the moderate to extreme part... now, im thinking it SHOULDNT (still might) be rings... im gonna go out there once the wind from t.s. ernesto dies down a little more, and put some oil into the cyl to see if that makes anything change. If nothing change, im pretty sure i can rule out rings... WORST CASE scenario, it could be cracked head... which i highly doubt because of the small bore on the RB20 and so much material... so that leaves me back with blown headgasket or bent valve... anyone else have any insight on what it may or may not be?

Phil

[MeanGreenS13]

put about 1 1/2 caps worth of oil in each of the bad cyl's no change... i'm gonna try one more thing before ruling out the rings. gonna put some ATF in each cyl and let it sit for a couple days. Im thining the rings may be stuck cause of how long these motors sit... if the rings are stuck according to my friend kenny (nissan tech) that should free them up and they would then seal.. im REALLY Leaning towards it being a blown head gasket just because they are 5 and 6... side by side.. any more suggestins on things to try would be GREATLY APPRECIATED!

phil

[themadscientist]

You could pull both sparkplugs, screw a compression gauge in one cylider and pressurize the other cylinder and watch for pressure escaping into the first on the gauge. I would call that a bad head gasket.

[MeanGreenS13]

ill definitely try that... so basicly, put the compression tester into 5, and get a leakdown and plug it into 6, and pressureize using the leakdown tester? but what would happen since the valves will be open on one of them?

[kjlindgr]

A leak down test will tell you EXACTLY what the issue is. There will be no need for caps of oil or guessing what the problem is. It will tell you if it's rings, a head gasket, intake or exhaust valves. Compression tests after you already know there is a problem are useless.

If you truely did a leak down test, you wouldn't need to ask. Either way, when you say "moderate to extreme", what percentage leak through are you talking about?

[MeanGreenS13]

its up around 70-75% leakage.

[kjlindgr]

Is there any way you can get access to another leak down tester to determine what the issue is since the place that did it the first time didn't know what they were doing?

[MeanGreenS13]

what in the world are you talking about, i did it... like i stated above.. I put the cap of oil in there to try and seal up the rings to see if that was the problem after consulting my friends mark and kenny, both nissan tech's for 10+ years. its a brand new matco tools tester that i purchased and as i said, when i saw that 5 and 6 were low, i went back and checked one of the ones that came out good and nothing had changed. it was still good

[RB20DETodd]

probobly will be fine, once you fire it up and run it it should be good.

[MeanGreenS13]

well im gonna be tearing it down to do some internal work, but if something other than i planned to do is wrong i need to know, yanno... ive got 25 days left out of my 30 day startup warantee on the head and block, i just dont see why 1 2 3 and 4 are PERFECT and 5 and 6 are junk unless something is wrong....

[Darius]

I'm guessing that your head gasket is blown and if that is the case, don't forget to resurface the head and block because the mating surfaces could have been deformed due to the leak.

[kjlindgr]

what in the world are you talking about, i did it... like i stated above.. I put the cap of oil in there to try and seal up the rings to see if that was the problem after consulting my friends mark and kenny, both nissan tech's for 10+ years. its a brand new matco tools tester that i purchased and as i said, when i saw that 5 and 6 were low, i went back and checked one of the ones that came out good and nothing had changed. it was still good

You aren't supposed to do this when you do a leak down test. Compression test, yes. Leak down tests are WAY different and you need to rely on hearing where the problem is. Apparently you are the one that doesn't know what you are talking about.

If you were leaking past the rings, you are able to hear the air blowing past the rings and into the oil pan. No need to add a cap of oil or that other nonsense.

[kjlindgr]

I'm guessing...

Why are you guys guessing still? A blown head gasket will be obvious if a leak down is done. You'll be able to hear air blowing through the water passages. If he's having 70-75% leak, you'd probably be able to feel it too.

[MeanGreenS13]

ok kjlindgr im sick of you already thinking your GOD. back the **** off *******. its a blown headgasket we found oil that looked like chocolate icecream ontop of the caps that go over the cams themselves. lock this thread

[kjlindgr]

ok kjlindgr im sick of you already thinking your GOD. back the **** off *******. its a blown headgasket we found oil that looked like chocolate icecream ontop of the caps that go over the cams themselves. lock this thread

A little salty knowing you were wrong, are we?

[Eikon]

Thread is locked.

MeanGreen... glad you found the culprit.. I'm sure your happy to find out it was the head gasket and not something worse. Keep us updated on the project!

ok kjlindgr im sick of you already thinking your GOD. back the **** off *******.

Settle down a bit. Kjlindr is God as far as I'm concerned. He's one of the most experienced, knowledgable RB guys around.