Minor Rust in Engine (inside valve cover on Cylinder head)

86invader

Cadet
Joined
Sep 22, 2011
Messages
23
Well i have a 1990 Four winns 190 freedom with a 4.3 engine. While i was checking the oil today after a LONG day at the lake sunday I checked the oil and noticed it was full and color was good (No water in oil) BUT when i took off the oil cap to see how clean the engine was inside i see rust depostis inside the head on the springs and on the Cylinder head casting (It looks fresh) I being in the automotive field am VERY good at maintaining my vehicles.Boat and i want to know if i need to worry now and get it into the shop Again or is there a Oil that i can use to get rid of the rust deposits in the engine. I have noticed a little hesitation minor vibration but nothing major. The boat was given a clean bill of health from a local Recognizable shop here in phx az. So i am wondering if i need to start saving up for a major repair (Another 1800.00) or what? the 1800 was for a complete tune up and all fluid change and some other garbage. Please let me know what i should do any ideas, Like i say the rust is on the inside of the head and there is NO WATER UNDER OIL CAP! so i think im clear of a head gasket failure. Thank you dave
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
Re: Minor Rust in Engine (inside valve cover on Cylinder head)

1990 that's 23 years old.
Your car runs EVERYDAY.It heats up and expells the condensation.
Your boat motor gets used WAY less.
The condensation forms and stays in the motor.
Light rust can form.
Usually not a problem.
 

Boomyal

Supreme Mariner
Joined
Aug 16, 2003
Messages
12,072
Re: Minor Rust in Engine (inside valve cover on Cylinder head)

1990 that's 23 years old.
Your car runs EVERYDAY.It heats up and expells the condensation.
Your boat motor gets used WAY less.
The condensation forms and stays in the motor.
Light rust can form.
Usually not a problem.

Ditto! All the more reason to start it up occasionally during the off season.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
Re: Minor Rust in Engine (inside valve cover on Cylinder head)

I've got twin outboards.
One day I went out to do some general maint.
I removed both cowls.
Under the cowls it was like it had rained.
The condensation was terrible!!!
Since then I've started putting the covers on and NOT locking them down, leaving about 1/2 in space.
It lets them breath and no more condensation.
Guess condensation isn't too much of a problem in Az.
Just keep the oil fresh, and if the problem persists remove the oil fill and let it breath??
Just make sure you install it before you go fo a ride.
 
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