Volvo Penta 3.0 GLP-D (PCV valve popping off while running - carbon buildup on boat thru exhaust)

TulsaTime

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Hello, my PCV valve is popping off the valve cover insert. What is going on here? Vacuum leak to Carb?
Also,
Took this boat to the mechanic and he jacked with the carburetor somehow, I think to by-pass the electric choke? It's running and starting a lot better, but now the above mentioned issue is happening and now it's throwing black carbon film all over the bottom of the boat towards the transom area. Any help is appreciated!
Thanks
 

Bondo

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Ayuh,..... Not sure on yer Volvo, but generally speakin' that pcv should be just an open elbow to vent the crankcase,....
The carbon black is because yer carb is afu, 'n is runnin' waayyy to rich,....
 

TulsaTime

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Ayuh,..... Not sure on yer Volvo, but generally speakin' that pcv should be just an open elbow to vent the crankcase,....
The carbon black is because yer carb is afu, 'n is runnin' waayyy to rich,....
Thanks Bondo,
I'll look into adjusting that 2 barrel. Still totally blown away by the PCV valve popping off. Maybe it's stuck - I'll check it out.
Thanks again for all the help!
 

Lou C

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If there is an actual PVC valve in the valve cover instead of just a hose leading to the flame arrestor to take care of blow by, yes if the valve gets stuck blow by building up in the valve cover has to escape and can blow it out if there is a lot of blow by.
That Holley carb does have the electric choke and it needs a constant source of voltage to keep the choke open. If you have all that carbon the engine is running way too rich. Fix it right, it is not rocket science! Either you don't have voltage to the choke heater (remember there are 2 connections) or the choke heater is bad. Auto shop 101 stuff here.
 

Lou C

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There are no PCVs on boat engines with carbs.
I looked up the OP's model in the Volvo catalog and guess what I found...
part #13, valve, crancase ventilation.
 

bruceb58

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I looked up the OP's model in the Volvo catalog and guess what I found...
part #13, valve, crancase ventilation.
I stand corrected.

Kinda interesting it has an elbow as well. Wonder what the PCV even does.
 

Lou C

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for it to really function as a PVC it has to be connected to manifold vacuum, I"d like to see where it is connected on the carb.
 

bruceb58

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for it to really function as a PVC it has to be connected to manifold vacuum, I"d like to see where it is connected on the carb.
I have PVC valves on my pool equipment! Never see one on an automotive engine before.
 

Scott Danforth

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lol, typing too fast.
in the old days we had a road draft tube....
in the really old days we had open valve train and you oiled it ever 10-15 miles with an oil can
 

TulsaTime

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Thanks for all the help. Here's a pic of the PCV valve location.
 

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  • InkedVOLVO PENTA 3.0 GLP-D-PCV VALVE.jpg
    InkedVOLVO PENTA 3.0 GLP-D-PCV VALVE.jpg
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Lou C

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Is the other end of that hose connected to the intake manifold? Or a vacuum port below the level of the throttle plate on the carb? Should be either of those for it to work as a PCV valve…they need manifold vacuum to work
If that valve is gunked up with sludge inside it may not be working. Sometimes you can clean them with carb cleaner and compressed air otherwise replace it
 

TulsaTime

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May 26, 2009
Messages
111
Is the other end of that hose connected to the intake manifold? Or a vacuum port below the level of the throttle plate on the carb? Should be either of those for it to work as a PCV valve…they need manifold vacuum to work
If that valve is gunked up with sludge inside it may not be working. Sometimes you can clean them with carb cleaner and compressed air otherwise replace it
Thanks Lou C.
I'll clean it to see what's happening! If not cleanable, I'm ordering one ASAP!
 
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