Valve cover

lrlima

Petty Officer 1st Class
Joined
Oct 16, 2005
Messages
223
1993 4.3 OMC
First off, sorry for the long post. But I want to thank everyone on this forum for their recent help as well as all of the other posts that helped me with my recent motor swap. I successfully swapped out a 4.3 motor with a reman one...Considering that this is my first boat and I didnt even know where the starter was when I bought it...this is quite the accomplishment. I owe it all to this board. Amazing what friendly advice and patience (a lot) can do for you...

Only one issue I am having since the swap. Runs great and Im still in the process of break-in, however I have a bad valve cover leak. I'm 99% sure its the valve cover due to where the oil is accumulating, but I cant actually see it leaking cause the manifold is in the way. It doesnt leak while on the muffs or at idle. Only when I go over approx 2000 RPM or ride around briefly. Oil pressure is approx mid to upper 40 while cruising.

I've tried everything I can think of to fix - new gaskets(rubber type) , tighthened, retightened, loosened, double gasket, etc...Its still leaking. Any advice or tips to fix?
 

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
Messages
62,321
Re: Valve cover

Which type of valve cover do you have?
Left or Right

4.3%20Valve%20Cover.png
 

Reel Poor

Vice Admiral
Joined
Jan 29, 2005
Messages
5,522
Re: Valve cover

Where is the oil accumulating ?

Check the valve cover closely, they are notorious for rusting out where the side of the cover meet the gasket lip. There is a groove all the way around the cover. Look along this groove.

Doubling gaskets will never stop oil leaks.
 

lrlima

Petty Officer 1st Class
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Oct 16, 2005
Messages
223
Re: Valve cover

DonS, it is the type on the left. FWIW non-vortec motor, non-balance shaft

Reel Poor, the oil seems to be trickiling down the side of the block and collecting on top the main water hose from the transom. Then it keeps dripping down into the bilge.

I saw some bubbling in the groove you mentioned, but I didnt see oil coming through any of those spots. Perhaps it is losing is strenght in that area? The lip where the cover sits had oil on it when I removed the cover.
 

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
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62,321
Re: Valve cover

You probably need a new valve cover. If the groove got bent up or down a little bit it will always leak.
Shouldn't be too hard to find a good used one.
 

lrlima

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Oct 16, 2005
Messages
223
Re: Valve cover

Thanks again for the replies. I'll find another one and post an update...I I figure if this is the biggest problem I had during the whole motor swap, then I'm thankful...
 

lrlima

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Messages
223
Re: Valve cover

One last question - will Vortec covers fit on a non-vortec motor? They seem pretty easy to find.
 

180shabah

Rear Admiral
Joined
Mar 26, 2005
Messages
4,995
Re: Valve cover

Heres a quick one Don,
Are there two different versions of the valve cover on the right? I have that plastic cover with Vortec on it, but I do not have the vortec heads(6 IM bolts per side).
 

djvan

Chief Petty Officer
Joined
May 3, 2003
Messages
411
Re: Valve cover

I know they make converters for automotive v 8's to put center bolt style valve covers on an older perimeter bolt head. I have no experience with these. Don't know if the v 6 motors have them available or not.

I HAVE NO IDEA IF THESE WOULD WORK ON MARINE ENGINES OR NOT.

DougV>
 

lrlima

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Oct 16, 2005
Messages
223
Re: Valve cover - UPDATE

Re: Valve cover - UPDATE

Wanted to post an upate in case anyone ever has a similiar situation. Turns out it wasnt the valve cover at all. This after 4 or 5 times reseating it, pulling the manifold to get a closer look, , etc (I'm getting real good at pulling apart the left side of this motor).

After hanging upside down in the engine compartment with the motor running on muffs, I could see a "mist" coming UP from just above where the oil pan connects to the block. Right next to where the drain plug is at the lower part of the block there is a friggin hole that angles up. Put my thumb over it, mist stops.

When I was swapping all of the parts from the old motor I didnt see a bolt / plug for this area as the original was rusted on the old block. On the new one it doesnt even look like there are threads in the hole( i thought it was used for casting or something). I have no idea why its even there or what purpose it serves. ANyway, if anyone has any advice on what to block this with, thanks. Otherwise this was my first motor swap and everything runs great. Thanks again to all who helped, and please stop laughing at the noob now:)
 

Bondo

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Apr 17, 2002
Messages
71,110
Re: Valve cover - UPDATE

Re: Valve cover - UPDATE

Ayuh,............

That's where the Dipstick goes if this motor were in a Car or Truck............Or even some Boats,.......
I bet your Oil Pan has the Dipstick in It........

I Think there's a Rubber Plug available for that,......

Don might know......
 

lrlima

Petty Officer 1st Class
Joined
Oct 16, 2005
Messages
223
Re: Valve cover

thanks Bond-o. Yes, the oil pan holds the dipstick. you're probably right about the rubber plug, as there arent any grooves.
 

superpop

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Joined
Mar 5, 2006
Messages
869
Re: Valve cover

Ahh memories, I have a 96 4.3L v6 that had the same oil leak. As I read your post I was going to suggest this as the culprit but you beat me to it. I just pounded a piece of wooden dowel into the hole. Went and purchased a freeze plug that I could have pounded in if the motor was out but gave up on that after a few bloody knuckles. The dowel has held up for 3 years now with no leaks or problems. Had the motor out this winter for a complete reseal and it still looked good. It is cast there for the dipstick. I would double check your starter as I had to replace mine after this prolonged oil bath that I was giving it. what a mess that made.
 
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