sockmonkie Posted August 14, 2016 Report Share Posted August 14, 2016 Hey folks. My '72 521 daily driver has started pushing what looks like a grayish smoke from the open block vent AND the vent on my valve cover. There was always a little tiny tiny bit coming from the block vent but now there is alot! Like to the point of embarrassment. I've only driven her a couple of time since it started. So what do you guys think it could be? Please don't say rings.... Quote Link to comment
tr8er Posted August 14, 2016 Report Share Posted August 14, 2016 K. I won't. Sorry. Quote Link to comment
Draker Posted August 14, 2016 Report Share Posted August 14, 2016 It rhymes with sings. Quote Link to comment
Draker Posted August 14, 2016 Report Share Posted August 14, 2016 What's the history on this motor? Quote Link to comment
Draker Posted August 14, 2016 Report Share Posted August 14, 2016 Have you compression tested it? Quote Link to comment
sockmonkie Posted August 14, 2016 Author Report Share Posted August 14, 2016 Yeah, I'm figuring that it's the rings but I've never dealt with this before and wanted to get the community's thoughts. Not that I'm scared to do the job, I just don't really have a place to do the work. But I guess I'll just have to do with what I've got. Odometer reads 28k so it could be 128k,228k.... but I'm guessing 128. I haven't tested compression. Quote Link to comment
datzenmike Posted August 14, 2016 Report Share Posted August 14, 2016 Your block vent should be connected to a PCV valve. Get that connected first. Could just be oil fog getting on the hot exhaust manifold... and don't plug it, get it set up right. Quote Link to comment
banzai510(hainz) Posted August 15, 2016 Report Share Posted August 15, 2016 over full oil??????????? ck the temp and water in rad see what it looks like. Quote Link to comment
datzenmike Posted August 15, 2016 Report Share Posted August 15, 2016 Rings don't suddenly go bad unless over heated and you keep driving the shit out of it till it stops running. Otherwise it's a long process. All engines have some amount of blow-by. This is gasses that get past the rings into the crankcase and want OUT. If you are over filled with oil there will be a lot of splash and oil 'fog,' and blow-by will drag some out with it. Specially out a disconnected block vent. A correctly connected PCV pipe and hose will give the oil fog more chance to separate out and run back into the engine. Sudden large amounts of blow-by can be a damaged piston lands and rings. A compression test that shows something like 130, 125, 135, 40 PSI would indicate the cylinder responsible. Quote Link to comment
sockmonkie Posted August 15, 2016 Author Report Share Posted August 15, 2016 Thanks for the thoughts,guys. Datzenmike, I was already in the market for getting that hose between the block vent and the intake but damned if any online stores have them in stock. I found something that MIGHT work at a local parts store but I'll have to investigate further. I don't tend to drive her hard, like ever. I'll get to getting a hose on there but after driving to my storage unit yesterday,I do think that I've got a bigger problem that just that hose. I've driven the old girl during all seasons for several years and have never seen this. I'll keep you all posted. Thanks again for any and all comments and ideas! Quote Link to comment
banzai510(hainz) Posted August 15, 2016 Report Share Posted August 15, 2016 crank case tube to the PVC valve on lower intake is a stock Nissan item. the valve cover hose I route to the Weber DGV or to the stock aircleaner is you can find that hose. Otherwise I rout e water line hose to the ground. Evcessive oil is bad. Quote Link to comment
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