Oil Leak 4.3 Mercruiser

[ransbach]

I need some help. I have leak on the bottom of my engine. I wiped it down as best as I could the other day, and when I returned today I found more oil leaking. I have few pictures attached. Any help would be greatly appreciated.

 

[Bt Doctur]

Re: Oil Leak 4.3 Mercruiser

timing cover seal?

 

[Alpheus]

Re: Oil Leak 4.3 Mercruiser

Did you run it after you wiped it down the first time? Or is this just after sitting unused for a couple days???

 

[ransbach]

Re: Oil Leak 4.3 Mercruiser

The other day it looked the same with oil in the bilge. I wiped it down, ran the engine...more oil...wiped it down and left it for a few days...oil also in the bilge

 

[ransbach]

Re: Oil Leak 4.3 Mercruiser

If it is the timing cover gasket can it be repaired with the engine in the boat?

 

[Alpheus]

Re: Oil Leak 4.3 Mercruiser

If it is the timing cover gasket can it be repaired with the engine in the boat?

If its the front crank seal? Yes. Pull the harmonic balancer off, remove and replace the seal. If its the actual timing chain cover gasket? Probably not. The oil pan must be lowered in order to change that. You can usually get them off without dropping the pan but you will never get it back on and sealed correctly if you don't.

On that note. I have rarely seen the timing chain cover leak with the new style plastic covers. They have a good rubber seal around them and its pretty hard to over tighten them do to the custom grip length.

Check and make sure that all of the timing chain cover bolts are tight. A couple may have come loose. If they are you may want to look into changing your front crank seal...

 

[BAproject]

Re: Oil Leak 4.3 Mercruiser

It is possible that the seal on the cover has gone south. Agreed that the seal from the block to the cover rarely leaks. It looks like you have a cast timing chain cover, but my 4.3 has the stamped version, and it is possible to replace while the engine is in the boat, but I warn you , it's not easy and is certainly not the proper way to do it.

 

[Adirondack]

Re: Oil Leak 4.3 Mercruiser

Maybe it's just me, but isn't that a pretty impressive looking crack in your second picture?

 

[BAproject]

Re: Oil Leak 4.3 Mercruiser

I think it's just you, I don't see a crack

 

[Adirondack]

Re: Oil Leak 4.3 Mercruiser

I think it's just you, I don't see a crack

Yup, must be me. Out of curiosity if you look at the second picture right next to the largest droplet of oil, what am I seeing?

 

[BAproject]

Re: Oil Leak 4.3 Mercruiser

I think that's where the oil "line" is, basically where right around the lowest point, but I don't think its a crack, if it were then oil would have to drip upward. I did notice that the hose to the right is covered with oil so it's not just a small leak it has to be a bad seal that is shooting pressurized oil all over the place

 

[Adirondack]

Re: Oil Leak 4.3 Mercruiser

I think that's where the oil "line" is, basically where right around the lowest point, but I don't think its a crack, if it were then oil would have to drip upward. I did notice that the hose to the right is covered with oil so it's not just a small leak it has to be a bad seal that is shooting pressurized oil all over the place

Still looks like a crack to me. Runs right around the edge, and at the other end takes a turn and runs down the rib. But hey. It's a picture. can't run a fingernail over it to check.

 

[paultjohnson]

Re: Oil Leak 4.3 Mercruiser

Damn sure looks like like it could be a crack to me also. It almost seams like it continues on the other side of that ridge to the left by the numbers molder in the metal Good eye-- OP can you wipe the oil and snap some more pics? Even on the 1st pic If u hit the magnify button on computer it looks cracked on the left also hmmmm.................

 

[BAproject]

Re: Oil Leak 4.3 Mercruiser

If it is a crack then it does not explain how oil can travel upwards to the bottom of the timing chain cover. IMHO

Only 1 way to tell, wipe it down and snap another pick. Looks like oil is just pooling to the lowest point, and also seem like a very unusual place for a crack

 

[ransbach]

Re: Oil Leak 4.3 Mercruiser

Initially I also thought it was a crack but the appearacne is equal on both sides of the pan. Also, the oil is leaking from above that area ....so I do not believe they are cracks, I could be wrong. Any one else have a picture of a 4.3 oil pan?

 

[Adirondack]

Re: Oil Leak 4.3 Mercruiser

Oil can "wick" in some pretty funny directions over a porus cast surface. The crack could also be causing a bad seal at the gasket above it allowing the oil to also seep down. Another wipe with a pic of a clean surface would help.

 

[ransbach]

Re: Oil Leak 4.3 Mercruiser

I will not be able to get to the boat today. After Earl passes, I'll head on down to the boat and wipe off the oil and take more pictures. Thanks all.

 

[Alpheus]

Re: Oil Leak 4.3 Mercruiser

I did a quick search here om iboats and came across this.

http://forums.iboats.com/showthread.php?t=205350

Same exact problem with darn near identical pics.

That is not a crack its a casting mark. This engine is using a cast aluminum oil pan not stamped steel...

 

[Adirondack]

Re: Oil Leak 4.3 Mercruiser

I did a quick search here om iboats and came across this.

http://forums.iboats.com/showthread.php?t=205350

Same exact problem with darn near identical pics.

That is not a crack its a casting mark. This engine is using a cast aluminum oil pan not stamped steel...

For some reason I can't get to the pics in the other thread, but I definitly trust your research. I could see it was a cast pan. I'll leave it with saying that that is one freaky and deceiving casting mark. 2D pics never give the whole story.

 

[Alpheus]

Re: Oil Leak 4.3 Mercruiser

I dont know why you cant see the pics but Ill repost them.

If you look close you can see the same ca`sting marks (lines)

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