pcv hoses

LI Bill

Cadet
Joined
Apr 30, 2006
Messages
13
1988 24' Renken cruiser 5.7 mercruiser. Does anyone know where the pcv hoses out of the valve covers go? On my engine they just lie under the flame arrester, dont really attach to anything. Is this normal? Thanks guys.
 

tommays

Admiral
Joined
Jul 4, 2004
Messages
6,768
Re: pcv hoses

Ya there put there so the fumes get sucked back into the motor and dont build up in the bilge and make a poof<br /><br />They should hook on to clips on the flame arrestor<br /><br /><br />tommays
 

JustMrWill

Master Chief Petty Officer
Joined
Aug 12, 2003
Messages
877
Re: pcv hoses

like this...<br />
100_0257.jpg
<br /><br />-JMW
 

crawdadric

Petty Officer 3rd Class
Joined
Nov 29, 2005
Messages
88
Re: pcv hoses

Bill K.<br />On my Merc 5.7 there is a hose on the starboard side valve cover and goes to a fitting that looks like a PCV valve. That hose goes directly to the flame arrestor. On the port side valve cover there is a PCV Valve and it goes to a fitting under the carburetor. I have to take another look to be sure, but I know that the PCV hose does not go to the flame arrestor.
 

tommays

Admiral
Joined
Jul 4, 2004
Messages
6,768
Re: pcv hoses

There should JUST be vent hoses hooked up to the valve covers Boats dont use PVC valves<br /><br />BUT people do stick them in for some reason ?<br /><br /><br />tommays
 

LI Bill

Cadet
Joined
Apr 30, 2006
Messages
13
Re: pcv hoses

Thanks guy's, I'll take a look for the clips on the flame arrester. I have a bunch of funky looking stuff on this boat and am trying to sort it it out...
 

mkast

Lieutenant Commander
Joined
Nov 6, 2002
Messages
1,934
Re: pcv hoses

Originally posted by tommays:<br /> <br />BUT people do stick them in for some reason ?<br /><br /><br />tommays
After pricing the replacement fittings for these hoses from Mercruiser, I can see why.
 

crawdadric

Petty Officer 3rd Class
Joined
Nov 29, 2005
Messages
88
Re: pcv hoses

I just bought all of the tune up parts for a 2000 5.7L Mercruiser and the web site I used (stem to stern), listed the PCV Valve in the Mercruiser parts diagram. Item number 8 on the valve cover section, Mercruiser part number 21-861476.
 

Buttanic

Senior Chief Petty Officer
Joined
Sep 25, 2003
Messages
711
Re: pcv hoses

The vacuum from PCV valve on a sealed engine helps prevent oil leaks. It is uncommon to find oil seepage and leaks on new cars since the manufacturers sealed the engines and and used the PCV valve to maintain a vacuum in the crankcase. It is a very good way to prevent oily bilges.
 

mkast

Lieutenant Commander
Joined
Nov 6, 2002
Messages
1,934
Re: pcv hoses

I am unfamiliar with later model Mercruiser engines. The late 80's vintage engine I use has what looks like a PCV. In reality it's empty, no disc or spring, you can look through it, as in hollow. Mercruiser wants $15 for it. Picked up a stock valve at a parts store, busted the guts out of it. Three dollars.
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,093
Re: pcv hoses

the reason is under cruise to WOT ,there is no manifold vac. to speak of.thats why they lead to the flame arrestor and get sucked in.
 

Buttanic

Senior Chief Petty Officer
Joined
Sep 25, 2003
Messages
711
Re: pcv hoses

Bt Doc, you only need 5 or 6 inches of vacuum for it to work. There is at least that much at cruise and maybe at WOT if it has a 2 barrel.
 
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