PCV on 3.0

[DayCruiser]

I got a film of oil on top of the engine and a very slow drip down the side.<br />1990 3.0 Merc. Raining outside so I can't go check. I got a hose coming out of the top going to the carb(where moost of the oil congregates.HOw do I replace the PCV? Or do I just unstick it? Do I have to take the valve cover off?

 

[Dunaruna]

Re: PCV on 3.0

Hi DayCruiser,<br /><br />Could be a blockage or something more serious like too much blowby (worn rings). Replace the hose if it is hard and brittle, give the ports a cleanout. Removing the rocker cover is a good idea, you'll be able to see how much crud has built up over the years. I didn't think your model had a valve in the breather line but if it has they can be cleaned out with carby cleaner and compressed air, its good to go if the ball inside rattles freely (suck & blow to test). If you can't free it up then replace it.<br /><br />Aldo

 

[Don S]

Re: PCV on 3.0

Neither the 1990 nor the 1989 3.0L engines had pcv valves in them. There is nothing more on the valve cover than a connector for the hose that goes to the flame arrestor.<br />If you are getting excess oil out of the hose, it sounds like blow by. Time to do a Compression Test both dry and with oil in the cylinders. Sounds like your engine is getting tired.

 

[DayCruiser]

Re: PCV on 3.0

Thanks for the info. Man a tired engine dont sound good at all. I will do or get somebody to do what you guys say.I dont know if this is good or not but the engine only smokes on warmup/startup-- from then on there is nothing. I think it used a quart or 2 all season. <br />A really good thing is I got a good deal on this boat a couple of years ago and therefore can afford to repair and/or fix the entire engine if need be. But it has full power right now and the blow by is probably a half a cup. i want to try and get that stopped though

 

[DayCruiser]

Re: PCV on 3.0

When I got this boat the hose from the engine wasnt hooked up to the spark arrestor. I hooked it up. Before that I cant remember any oil in the bilge area. Maybe thats why it wasnt hooked up. I took the hose off and everything looks clear. I blew out the spark arrestor. I need to remove the rocker cover(as soon as I find out where that is) Without a PCV, I see no reason to leave the hose connected to the spark arrestor so it can just blow (however slightly) oil into the Carb??

 

[tommays]

Re: PCV on 3.0

it has to be connected like that it draws fumes from the motor that can build up in the engine comparmemt and cause a explosion hazzard<br /><br />there are a lot of things in the engine area that may not make sense but there is a reason they are done that way and most of the time it is for saftey reasons <br /><br />its good to buy a service manual and just sit back and read up it will make it easer to understand why things are done how there done<br /><br />tommays

 

[DayCruiser]

Re: PCV on 3.0

Ok thanks tommays. I will go back and hook it up. I definitly need a manual too

 

[deputydawg]

Re: PCV on 3.0

It sounds like you don't have any real serious problem. Your engine is definately getting worn out though. If it helps you, some parts of the world we call the rocker cover a valve cover <br />Your engine smoking at warm up just shows it is suffering from normal wear. After the engine warms up, things expand and seal tighter. 1 to 2 quarts of oil all season is not bad, unless you only rode for an hour all season.<br />I would bet you that if you run the engine at idle for 5 or 10 minutes, then pop the throttle open it belches a cloud of smoke for just a second. The valve seals and guides are worn.<br />Good news is the engine will probably run a long time like this. If it is leaking oil into the upper cylinder walls through bad rings or valve seals/guides then you are definately getting oil to the top of the cylinder. Do a compression check. If all cylinders are equal, I would wait another season to go through the engine. By waiting you run the rick of causing more wear to the cylinders, but at this point I don't think that is a problem. <br />Definately leave the hose attached to the spark arrestor. Not only does it do what Tommays says, it also helps pull pressure from your crankcase. With this unhooked it might build up more pressure in the engine and cause main seals to leak.<br />Do the compression test (on a warm engine) and let us know.

 

[DayCruiser]

Re: PCV on 3.0

Ok thanks for the advice deputydawg. I hooked it back up.<br />I am getting it out of the water wednesday for winterizing and let the shop check it out. <br />No more clicking since I replaced the slave solenoid switch.<br /> I will get the shop to replace the wiring going to the electronic ignition. That short is still making the gauges jump about every 30 minutes. but unlike before they correct themselves pretty quickly. The short may be making the engine/fuel injection flood? Or not run right in some way?<br />It got to be getting worn as yall say too. 14 years of life take its toll. It still has a lot of get up and go

 

[DHPMARINE]

Re: PCV on 3.0

Daycruiser,<br />just a few thoughts......<br /><br />1990 3.0 L Mercruiser probably is not fuel injected.<br /><br />Probably no PCV valve either.<br /><br />when you find the valve rocker cover,you'll find a few screws missing or at least loose.<br /><br />this will correct your problem.<br />DHP

 

[DayCruiser]

Re: PCV on 3.0

I thought it wasnt fuel injected but a car mechanic from down the street said it was. I will ask him again. Maybe I didnt hear right.<br />I know where the valve cover is lol. I dont see any missing screws. The oil is on top of the valve cover(mostly under the carb) and a film of it is on the spark arrestor. Very small drip going down the right side of the engine