oil sludge in exhaust manifold

[Bowyer]

I drained the water out of the exhaust manifold on my 4.3 for the first time as I just bought the boat, and it became blocked off by a build up of oil and sludge is that normal?

 

[Haut Medoc]

Re: oil sludge in exhaust manifold

I don't know about the oil part, maybe a little, or it just looks like oil....Sludge is very normal though.....If your up in Okanagan, how did you keep it from freezing during our last cold spell? I would be helpful if you posted what year/make/model we are talking about....BTW, welcome to the forum @ iboats .....JK

 

[ziggy]

Re: oil sludge in exhaust manifold

i don't think it's normal. though i don't know anything about yer perticular engine, but that's not the way i understand exhaust manifolds. i think they have waterjackets around them. there should be no way for oil to get into the waterjackets to be comeing out the drain hole. if by sludge ya mean sand and mud and rust and crap, that i'd think would be normal, but not a oil mix sludge,,,,how would the oil get into the cooling system? perhaps it's cracked. then i'd believe oil sludge mix would be possible....just my 2 cents. not knowing anything about yer engine... but i do like to guess at the answer....merry christmas and welcome. stick around, if ya like boats this is where the informed people hang out....<br />i guess it would be nice to know if it's a fresh water cooled or raw water cooled too....that might be relevat info too...

 

[Bowyer]

Re: oil sludge in exhaust manifold

Thanks for the replys. The boat is a 1991 Wellcraft with a volvo DP leg and 4.3 V6, fresh water cooled . As I drained the exhaust manifold on the one side alot of water came out and latter when I checked there was some oily sludge half frozen in the hole. The other side I had to replace as it cracked when I couldn't get the water out ( the drain plug was broken).

 

[flashback]

Re: oil sludge in exhaust manifold

Did you drain the block before the freeze? You should not have any oil in the manifold water jacket. I'll bet you have more problems than you think.. I hope not but it does sound bad..

 

[Bowyer]

Re: oil sludge in exhaust manifold

Flashback: the block wasn't drained as it has antifreeze in it and is good to -30C. That sludge must be from the exhaust somehow getting into that water jacket dose it mean it is cracked or what?

 

[Bondo]

Re: oil sludge in exhaust manifold

How's the P/S Fliud Level,...???.... Does your Volvo have an Engine Oil Cooler,..???....<br /><br />Either of these would be Up Steam from the exhaust manifolds,+ Could be Split Internally.....<br />And, they're on the Raw water side......

 

[Haut Medoc]

Re: oil sludge in exhaust manifold

So, how oily is oily.....Does it just look oily or does it be oily? We need a concentration factor, I think....If you have a cracked block or exhaust manifold there would be anti-freeze in your oil....What Bondo says could be true....Is it oil or PS fluid? When they mix with other kerap, it can be hard to tell....Oil will foam & get white though...eventually....JK

 

[Don S]

Re: oil sludge in exhaust manifold

I'm wondering if you are actually seeing oil, or just black water and assuming it's oily.<br />Manifolds will get scale build up in the bottom of the manifolds and it will plug up the holes (That's Normal). That's why it's always suggested to use a wire to probe the hole and make sure it clean when draining.<br />It is also usually a black or very dark brown in color, but it's not oily.

 

[Bowyer]

Re: oil sludge in exhaust manifold

I don't know if it has an engine oil cooler and the sludge is very black and thick.

 

[crazy charlie]

Re: oil sludge in exhaust manifold

Bowyer,if you are not sure if it is oil or just a black sludge then you probably give it a taste and find out for sure.Most manifolds have black crud in the bottom that can surely be mistaken for oily sludge.One way to tell is that oil is easily washed off your fingers and the crud that is in a manifold is a job and a half to scrub off.Also one tastes better than the other

 

[Bowyer]

Re: oil sludge in exhaust manifold

It is definitly "Black Sludge" because it stains your fingers and sticks like **** to an army blanket. I didn't have nerve enough to taste it!