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| PCV Valve; can a clogged one Really blow a seal? | |
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| Tweet Topic Started: Jan 24 2013, 03:29 PM (3,319 Views) | |
| snowfish | Jan 24 2013, 03:29 PM Post #1 |
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Basic GearHead
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General Forum Knowledge states that a restricted PCV valve will cause the Cam, and possibly the Crank Seal, to blow. I can not see how this is possible. ![]() The PCV Is Not Directly Venting, or even connected, to the Crank Case. Other than through the "Y" tube. Even if the PCV is 100% plugged, the crank case pressure will expand, forcing blow by to the air cleaner, via the quite large vent ports, equalizing the pressure. My take is that the PCV's job is to mix a little air, from the intake manifold to which it's attached, with the crank case blow by, to assist combustion when introduced back to the intake. Too much oil vapor blow by, to air ratio, and the classic oil fart is produced. |
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| Bad Bent | Jan 24 2013, 03:48 PM Post #2 |
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Facetious Educated Donkey
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Well, the PCV and tube clogging and cam seal blowing were simultaneous on my Geo. True, there is the Large UnRestricted Air Cleaner Port but that connects to a smaller plastic tube which narrows so something that looks like a 3/16 x 3/8 inch port above the TB throat. All of this is above the top of the Large UnRestricted Air Cleaner Port's dip allowing the port to collect blow-by and eventually plug. At least that's what I see.
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| Deleted User | Jan 24 2013, 04:07 PM Post #3 |
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Deleted User
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The seals that were blown out on the engines that I've seen this on had crankcase ventilation systems that were totally , among other things. The PCV valve does not turn on the Service Engine Light. Got to check it the old fashioned way. Suck and blow.
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| Memphis metro | Jan 24 2013, 04:18 PM Post #4 |
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The two that blew out on me on two differant engines had new pcv valves and the relief ports were not restricted with rtv. Where does that leave us? . |
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| Deleted User | Jan 24 2013, 04:27 PM Post #5 |
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Deleted User
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Something causes seals to leak and/or blow out. Gremlins? Because they're O.L.D.? Or, H.A.R.D. due to A.G.E.? It's not too hard to install one that's N.E.W. |
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| Memphis metro | Jan 24 2013, 04:30 PM Post #6 |
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Because the relief passage is not made correctly in the number 1 cam cap and its a piss poor design. . |
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| Deleted User | Jan 24 2013, 04:39 PM Post #7 |
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Deleted User
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I don't think so. I have never modified the passage in the #1 camshaft bearing cap, and I have never had a camshaft seal that I installed pop out. You think Suzuki would have issued a Service Bulletin if it was a problem? They have not. |
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| Memphis metro | Jan 24 2013, 04:58 PM Post #8 |
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Actually with the seal pushed all the way in to the lip stop they have, the passage is restricted. You can move the seal out just a bit and it will give it a little passage but its still small. Not near enough. Lots of times mechanical defects never get reported. Theres a lot of cam seal leaks on the forum and several that push out. Not all from rtv restriction. Something is causing it. |
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| rmcelwee | Jan 24 2013, 05:19 PM Post #9 |
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So much for your "large unrestricted air cleaner port". This is what I found on my Metro when my cam seal blew out: |
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| snowfish | Jan 24 2013, 05:36 PM Post #10 |
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Basic GearHead
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But it wasn't the PCV's fault, eh? The hose itself was full of crud. This didn't happen when the temperature was below freezing, was it? Looks like a bunch of moisture mixed with a little oil. The cool whip collapses and freezes. Then next start up, major pressure build and adios seal.
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| Deleted User | Jan 24 2013, 05:41 PM Post #11 |
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Deleted User
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Did yours blow out after you installed it? Also, the unmolested engines that I have seen do not have the camshaft seal pushed all the way in against the machined surface. A little attention to detail goes a long way. That's nasty! |
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| Deleted User | Jan 24 2013, 05:42 PM Post #12 |
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Deleted User
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Fixed. |
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| snowfish | Jan 24 2013, 05:52 PM Post #13 |
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Basic GearHead
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Doc may be onto something with the blocked passages. I've not be that observant. Yet, so far, nothing has popped. Now watch.....on the way home tonight.............
Even nastier with the smegma correction! Please folks, don't Wiki it! You won't like what you see.
Edited by snowfish, Jan 24 2013, 05:56 PM.
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| Memphis metro | Jan 24 2013, 07:31 PM Post #14 |
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Glenn, I understand the seal is supposed to be flush but even at flush there is very little room for bypass. There is very little room from flush to pushed all the way in as far as it goes till it hits the stop. Check it out the next time you have a seal and cap. It blew out like six months after I installed it on a day when the temp dropped several degrees cooler. Ran it all summer. Cold snap came and the seal blew out. . |
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| Deleted User | Jan 24 2013, 08:09 PM Post #15 |
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I look at it every time I put one in. No problems, here. |
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, among other things.
The PCV valve does not turn on the Service Engine Light. Got to check it the old fashioned way. Suck and blow.
Where does that leave us?
Now watch.....on the way home tonight.............
Please folks, don't Wiki it!
You won't like what you see.
7:58 PM Jul 10