Noisy Starboard transmission...rich engine

[405driver]

Ok... here's a question for those who have taken these engines apart. When we took the plenum off, it has an oil residue in it. It has enough to drip out. How did that oil get in there?

[bud37]

Sorry can't answer your plenum question, only done auto 454's..... but any updates, how is your guy doing with the engine otherwise...

[waybomb]

Crankcase ventilation system aka breather system?

[mjk1040]

Waybomb beat me to it. PCV valve plugged up? An engine has to breath and if the normal venting system is plugged it will find a new outlet. Mike

[405driver]

We are awaiting parts...mainly refurbished injectors. Should be back in a few days.

Does anyone know if an automotive PCV valve will work?

Thanks

[km1125]

Source of the post We are awaiting parts...mainly refurbished injectors. Should be back in a few days.

Does anyone know if an automotive PCV valve will work?

Thanks

The function is exactly the same, but I don't know if the rubber hoses are the same size. There are no safety implications to be concerned with.

[bud37]

Source of the post We are awaiting parts...mainly refurbished injectors. Should be back in a few days.

Does anyone know if an automotive PCV valve will work?

Thanks

just remove yours and take to Advance or pep or auto zone and match it...they will be some GM part, you will be fine.......

[waybomb]

How many hours on those engines?
You may have excessive blow by. I don't think you need new pcv valves; they seem to be working, drawing in air from your crankcase.
The amount of sludge may be normal, but if there is alot then maybe your engine is creating too much blow by
Also possible the breather vent is fouled and plugged..

[bud37]

One thing to add here to all of the above....., if there has been a large amount of oily residue it could also be due to a stuck PCV as well, they need to open and close due to engine vacuum.....they are cheap enough and I have found create some interesting issues while tuning, if not right....

[Viper]

Source of the post....Does anyone know if an automotive PCV valve will work?....

WHY???
So instead of going with the $9 OEM one, you'd rather run the risk of installing the wrong one? You may already have the wrong one in there that can be contributing to the problem. It's not as simple as matching a size to fit in the hole and accommodating the right size hose. I get the sense that the importance of this part is underestimated. This is part of a critical engine system designed to relieve crankcase pressures based on engine vacuum under varying engine loads, it helps alleviating moisture from the crankcase, recirculates un-burnt gases, and arrests/stops backfire pressures back to the crankcase....not something you want to get wrong.

Now if you were comparing apples to apples and were simply talking about two unmodified 454 engines, the part would be interchangeable, however, the two applications are different (marine and automotive), likely have a different vacuum curve, and that plenum you have would be considered a Mercury Marine modification, it is no longer a stock 454 GM. Having said that, I know this particular OEM part will fit a couple of other MERC engines of different displacements. The concern becomes; does the ECM expect to see a particular vacuum curve that the OEM part contributes to, because it does affect overall vacuum! One issue with modified engines (maybe Waybomb can weigh in) is PCV valve selection because engine modification changes the vacuum curve and often the original PCV valve is no longer suitable. Each design has its idle and cruise flow rate, and the transition vacuum level. Is there a comparable automotive cross? Probably, but it better be the right spec as compared to the OEM part number and not simply for any 454 engine.

If an automotive parts store can take the Merc # and cross it directly to another part with the same spec (good luck finding the spec to begin with), then fine but for a matter of $9 why bother, and possibly set yourself up for another problem that you'll likely never suspect is a result of the new PCV valve.