225 HP V8-Stringer: Oil in Coolant water.

[strikemike]

Our boat is over the winter in a hall. To test some stuff stands a large tub with antifreeze and water under the drive. So far, everything OK. After a short test, the (cooling) water turned black. It has a very light film of oil. The oil from the block is OK so far. Here I could find no water in the oil. I'm really stumped woren it is. Thought of the exhaust manifold, head gasket or crack in the head. Hope it's just a gasket or the exhaust manifold. Is there an easy way to test it?

Maybe it's really just oil from the oil change on the drive. Then the oil is everywhere in the cooling circuit. The engine has been running with the soup 1-2 minutes. Then I have to first of all "flush" and get out the oil there.I wanted tomorrow, re-measure the compression. Then I would rinse 1-2 times. The rest will come out in the summer of its own.

It is a 225HP OMC Stringer with 307 GM-Block. I'm really grateful for any tip.

 

[southkogs]

Welcome aboard StrikeMike: If i've got you correctly, you were running a Stringer drive in a tub of water.

My first guess is that you roasted your impeller. A Stringer drive needs to be nearly submerged in order to pull water properly ... at least the impeller needs to be completely flooded, so the waterline has to get up over the upper gear case. What you might be seeing is gear lube.

Do you have good compression on the engine?
Is the gear lube in the upper gear case and lower gear case milky at all?

What year Stringer is it?

 

[strikemike]

hi,

i have a flushing kit and e extra water pump for the flushing kit. everything is fine. I will check compression tomorrow. it is a electric shift Stringer. yes, i was also thinking of lube from the Drive.

 

[boobie]

As long as you have the flushing kit that replaces a trunion cap you can run it all day on that. Did it many times.

 

[jerryjerry05]

Year?
Does the system have an oil cooler?

 

[Scott Danforth]

isnt this the same motor that you were looking to replace in a different post? you were working on heads and thought you had a crack in the block?

 

[strikemike]

Scott: no, not thinking of replacing it. must be a different one.

jerry: Engine is from 1973. there is no Oilcooler installed.

 

[Scott Danforth]

Do a pressure test on the water jacket. If you have a crack, you will hear the pressure escaping.

 

[strikemike]

Little Update:
Compression on the Engine was between [FONT=Verdana, Arial, Helvetica, Geneva, Swiss, SunSans-Regular, sans-serif]131 and 145 PSI. Meanwhile testing we found 2 broken spark plugs. We replaced all the spark plugs and all the plug wires. With the new spark plugs & plug wires the engine runs great for now. After watching some YouTube Vids, a lot of people have a light [/FONT][FONT=Verdana, Arial, Helvetica, Geneva, Swiss, SunSans-Regular, sans-serif]oil film or "dark Water" while testing in a [/FONT]tub of water.