engine oil out the exhaust without burning it

[lab1484]

why would my 78 mercruiser 120 be dumping oil out the exhaust without burning it? plugs all look the same and doesnt smoke. but dumping about 4 quarts of oil in an hour, head gasket possibly?
appreciate any help

 

[mkast]

Re: engine oil out the exhaust without burning it

How did you diagnose this condition?
Exhaust gas is 1100 degrees F.
I think if oil was anywhere near the exhaust of a running engine, the oil would ignite.
Four quarts an hour???

 

[lab1484]

Re: engine oil out the exhaust without burning it

i noticed it first leaving oil slick behind boat. and it is definately engine oil. lost about 4 quarts, i guess your right about the temp on exhaust manifold it would be burnt and smoking, not sure how it is getting out of crank and in the water

 

[Haut Medoc]

Re: engine oil out the exhaust without burning it

why would my 78 mercruiser 120 be dumping oil out the exhaust without burning it? plugs all look the same and doesnt smoke. but dumping about 4 quarts of oil in an hour, head gasket possibly?
appreciate any help

4 quarts an hour?....
Are you sure it's not in the bilge?...
Do a compression test for starters, but I think that kind of consumption on an engine that seems to be running normally is impossible........

 

[lab1484]

Re: engine oil out the exhaust without burning it

ya its def not in the bilge, boat had a significant loss in power but did run, at a loss on this one guys

 

[bruceb58]

Re: engine oil out the exhaust without burning it

Somehow, the oil is getting into the cooling water through either a crack in the block or head gasket failure. I doubt you have an oil cooler on your engine but that would be a possibility if you do. Does your oil have any water in it?

 

[Haut Medoc]

Re: engine oil out the exhaust without burning it

ya its def not in the bilge, boat had a significant loss in power but did run, at a loss on this one guys

Compression check......
After that, I would pull the valve cover & see if the oil drain holes are clogged in the cylinder head....

 

[bruceb58]

Re: engine oil out the exhaust without burning it

Oh...missed the part about loss of power!

 

[lab1484]

Re: engine oil out the exhaust without burning it

thanks for your help, compression checks out only a few pounds difference in all the cylinders, to go back on my previous- i couldnt swear i guess that the oil couldnt be pumped out by the bilge pump, didnt really check that. but no obvious signs of oil leaking now. of course its not under pressure and leaking now. but might have missed that. there isnt any water in the oil at all

 

[Haut Medoc]

Re: engine oil out the exhaust without burning it

thanks for your help, compression checks out only a few pounds difference in all the cylinders, to go back on my previous- i couldnt swear i guess that the oil couldnt be pumped out by the bilge pump, didnt really check that. but no obvious signs of oil leaking now. of course its not under pressure and leaking now. but might have missed that

Well, it is going some where...
Either a leak inside the boat, (oil pan, loose fuel pump)....
You need to look in the bilge, clean it up & run it & look, even on muffs, that type of leak should be obvious....
The other possibility is out the exhaust/water port...
Run the engine on muffs, that kind of oil loss cannot go unnoticed through the exhaust.....
I would examine the oil that is in the pan by pumping it out to see what ot looks like...

 

[bruceb58]

Re: engine oil out the exhaust without burning it

If you did happen to have a leak between a water passage and a pressurized oil passage, you could test for this by doing a pressure test on the coolant side to see if it holds pressure.

 

[lab1484]

Re: engine oil out the exhaust without burning it

ok very good advise thank you. will run it this evening, praying it isnt the block. that should be impossible to find another one. ha. already have all gaskets planned on takeing the whole top end off engine this weekend to find problem. this old sea ray been in the family since day one gotta fix ya know
-motto is if its not at the bottom of the lake you can fix it

 

[bruceb58]

Re: engine oil out the exhaust without burning it

Are you in an area that has freezing temps?

 

[lab1484]

Re: engine oil out the exhaust without burning it

yes definately, indiana

 

[bruceb58]

Re: engine oil out the exhaust without burning it

Did you drain the block before this winter?

 

[lab1484]

Re: engine oil out the exhaust without burning it

that im not sure of it had set for 2 years before last summer

 

[lab1484]

Re: engine oil out the exhaust without burning it

well after removing alternator find the block cracked about in the middle between number 2 and 3 pistons, oil falling about straight on bilge pump. without even running engine water is seeping out of crack, more than sure thats were oil is coming from. so thats it i assume- the worst possible scienerio

 

[haulnazz15]

Re: engine oil out the exhaust without burning it

Yup, but on the bright side, the bilge pump was working!

 

[lab1484]

Re: engine oil out the exhaust without burning it

ha ya i guess, well looks like engine is coming outta there

 

[JustJason]

Re: engine oil out the exhaust without burning it

When you ran the boat water wasn't spraying out and all over the place? Those blocks crack on the right hand side (as viewed from looking at the front of the motor).
Problem is... There is no oil on that side of the block, just a water jacket. Something doesn't make sense. Take some pictures if you can. What did your spark plugs look like when you removed them. Any of them covered in oil?