blswan Posted September 16, 2019 Share Posted September 16, 2019 Hi all. I have a new to my 280z with triple weber carbs. I just purchased this car via auction last month. I have driven it half a dozen times and after warming up the I see white/gray smoke whisping from the valve cover breather. Should this have been recycled gas or is it indicative of an internal problem? My searches yielded several potential problems on stock engines. Any input would be great. Quote Link to comment Share on other sites More sharing options...
bunkhouse Posted September 16, 2019 Share Posted September 16, 2019 I'd start with a sniff test. You should be able to tell if it's fuel. Is the oil transparent or does it look like salad dressing or mayonnaise? Is it losing coolant? I'd also run a compression test. Quote Link to comment Share on other sites More sharing options...
blswan Posted September 16, 2019 Author Share Posted September 16, 2019 My buddy has the gauge so he is going to stop by tomorrow and we will run a compression test. The only smell I get is fuel... I will check the oil. No issues with coolant and operating temps / oil pressure / etc all read normal on the gauges. Thanks for the reply! Quote Link to comment Share on other sites More sharing options...
bunkhouse Posted September 16, 2019 Share Posted September 16, 2019 Does the engine oil smell like fuel too? Quote Link to comment Share on other sites More sharing options...
blswan Posted September 16, 2019 Author Share Posted September 16, 2019 I'll check tonight and report back. Thanks again. Quote Link to comment Share on other sites More sharing options...
blswan Posted September 16, 2019 Author Share Posted September 16, 2019 Checked oil. Can’t really say it smells like much of anything... maybe a little like fuel. Quote Link to comment Share on other sites More sharing options...
silverado22c Posted September 17, 2019 Share Posted September 17, 2019 To me, the system is operating correctly, given that the valve cover has a filter instead of being routed to the intake as intended from factory. You yourself said wisp, not large volume of smoke. I see it as just oil vapors escaping as it should. And the oil will smell of some fuel, with slight ring blow-by over time getting into the oil in the crankcase area. If it is not running right and smoothly, I would investigate. But if it is fine, don't overthink and just keep driving. From your picture, it seems like the vehicle was well maintained and they would have told you if such an issue was present before you buying the Datsun. Quote Link to comment Share on other sites More sharing options...
blswan Posted September 17, 2019 Author Share Posted September 17, 2019 Thanks for the reply Silverado. That's my dilemma; am I overthinking? Do I try to recirc the gas or address a possible nonexistent problem? I guess I downplayed the amount of smoke a bit... it does come into the cabin and rises from the hood so its more than wisps. I will run the compression test tonight and report back. Thanks all! Quote Link to comment Share on other sites More sharing options...
JMortensen Posted September 17, 2019 Share Posted September 17, 2019 Wispy steam/smoke is normal. I see you have a breather on the valve cover. What's going on with the block breather on the side? Is it connected to anything? When I had triples I had it going to a catch can. At every oil change I would have a couple inches of sludge in the catch can. Could also be hooked into the intake and that should cure the problem of smelling it. Quote Link to comment Share on other sites More sharing options...
blswan Posted September 18, 2019 Author Share Posted September 18, 2019 Well compression test didn’t go so well and more smoke coming out of both breathers. Here are the number so I have bad compression in two cylinders. Quote Link to comment Share on other sites More sharing options...
bunkhouse Posted September 18, 2019 Share Posted September 18, 2019 The 165s are satisfactory. If the valves haven't been adjusted for a while, try that and check the compression again. If you're sure the valve adjustment is fine, squirt a tablespoon or so of oil into the cylinders and take the c. test again. If the numbers raise significantly the problem lies in the rings. If the numbers stay about the same the trouble is in the valves. 1 Quote Link to comment Share on other sites More sharing options...
silverado22c Posted September 18, 2019 Share Posted September 18, 2019 That amount looks excessive and from your crank case breather, not the valve cover breather. I would see what it is like after you run the compression test again like Bunkhouse stated. Probably from the cylinder 5 rings. The smoke may get into your cabin, thru the vent that blows on the electronics in the passenger foot well, if you have it open. I don't know exactly what years have it or not. Maybe also thru the hvac intake if that is open. Quote Link to comment Share on other sites More sharing options...
blswan Posted September 18, 2019 Author Share Posted September 18, 2019 Thanks guys. Very disappointed obviously. I've driven the car maybe 10 miles since winning it on BAT. Well I had planned on doing an RB25DET swap with Fever Racing in Tampa. Its costly so I was hoping to drive this for a year while saving up but I guess its moving to the front of the list. Quote Link to comment Share on other sites More sharing options...
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