4.3 Mercruiser drips from rear of head..

[Kevoz]

Just found what I hope to be the last leak from the rear of a head when it is running, thoughts or suggestions. It was improperly winterized and I have reinstalled 2 freeze plugs. The heat risers were properly drained, so, they survived this time. This is my son's boat and it has sat in his driveway for several years, rotting away, he finally brought it to Dad to finish, just hope it is worth it. Btw, engine oil is clean. Has anyone seen just the head gasket fouled due to freezing or does it mainly crack something like the head or the block?
cheers,
Kevo

 

[Bondo]

Re: 4.3 Mercruiser drips from rear of head..

Ayuh,... Welcome Aboard Kevo,....

There's Manuals for that motor,+ drive up in the Adults Only section at the top of this forum,....
Have a Peek...

The odds are, Somethin's Cracked....
Not sayin' it Can't happen, but I've never seen a freeze failed headgasket myself...

 

[Kevoz]

Re: 4.3 Mercruiser drips from rear of head..

Thanks for the replies and the thoughts of reality, aargh! I have no problem with uncapping the engine, I just don't want to, waaaa! It has been 30 years since I have had a v8 or v6 apart, I am prone to inline or V4's of late, mostly Honda motorcycle engines for the past 10 years....I JUST HATE THINKING ABOUT IT! These are not Vortex heads, at least I dont think they are, anything differant between Mercruiser and automotive heads?
cheers, and thanks for the welcome!
Kevo

 

[Bondo]

Re: 4.3 Mercruiser drips from rear of head..

anything differant between Mercruiser and automotive heads?

Ayuh,... It's All about the Casting #s.....

If this is an 88, Nope, no Vortec...
It's probably worth the investment to go to Vortecs, with a matchin' Intake,+ 4bbl....

 

[Kevoz]

Re: 4.3 Mercruiser drips from rear of head..

Is it safe to assume (I know, I know) that the Vortex Heads and manifold will bolt up without any other major purchases? I have a 4 BBL carb on it now, but I am sure the heads aren't Vortex heads. Online places to purchase these items?
cheers,
Kevo

 

[sully73]

Re: 4.3 Mercruiser drips from rear of head..

it may be a long shot, but i know alot of the 4.3 auto motors were prone to intake leaks on the back because of a water jacket in the heads, but no passage in the intake. might be something to look at.

 

[Wingnutt]

Re: 4.3 Mercruiser drips from rear of head..

Before you start getting all bummed about yanking the engine, get a mirror on a stick and a flashlight and check your P/S oil cooler. Its usually mounted on the rear port side of the head or intake manifold. Any leaks will usually drip off the rear of the head and onto the starter. Ask my how I know this one.

 

[Kevoz]

Re: 4.3 Mercruiser drips from rear of head..

Yes, the PS cooler was leaking as well, but, on this engine, it is on the starboard side, and, since it wasn't doing anything like powering anything, I took the whole PS off which took care of one leak.
I am contemplating finishing the wiring of the dash and cabin, then, dropping it on some water and seeing if anything else shows up, it is just a drop at a time and no water in the oil, anyone see trouble ahead with this thought process? I really dont want to tear it apart at the moment if I can make some headway elsewhere and then gather more info about the problem before I make the jump.
thoughts, suggestions? And, btw, this forum has helped me a great deal. I have learned soo much in a short time about a lifestyle (boating) I have very little knowledge of...This engine was a complete reman Mercruiser w/only 20hrs on it when my son bought it!
thanks for all the help, here and with other posts,
cheers,
Kevo

 

[Kevoz]

Re: 4.3 Mercruiser drips from rear of head..

Ok folks, dropped her in the water yesterday am, had a few issues right off the bat, took care of those...then....oil started dripping out the dip stick tube at cruising throttle/planed out....then, after a while, a frothy mix of oil and water was leaking from the left head, towards the front of the engine, it could have been from the intake front seal, not sure, but, the oil leak has been there since my son has had the boat I am sure, since it filled the bilge with an oily mix like it was when he got it. The engine runs strong, sounds good and there is no water in the oil pan. Does anyone who has been in my shoes think there is a chance I can fix this with just replacing the heads? I know it is a question that can only be answered after the heads are off....What can I expect to see when the heads come off, what do I look for? The drip from the back of the head turned out to be dripping from the water jacketed exhaust manifold, not a big problem I think, but the oil coming out of the intake seal area or maybe the head gasket area is..thanks for all the help...Just looking for inspiration and maybe save a couple grand, lol....
cheers,
Kevo

p.s. lots of pics in restoration threads..