Rust in cooling system

[acdc96]

So I just posted a video of my engine running perfectly and when I was draining the manifolds and the block their were chunks of rust coming out. I thought that was odd so I dumped water in the manifold hoses and into the block to try to flush it out but theirs still chunks coming out. Since I've got it running perfectly and pumping water I don't want to have the engine to overheat and seize up.
Yesterday was the first time I let the engine warm up in a long time got it up to 140 degrees.
Should I keep flushing the engine with water until the rust stops coming out?

I also noticed the port side block drain had a weak stream of water coming out compared to the starboard side. (could be that the boat is uneven on the trailer) and the port side manifold was a lot hotter than the starboard.

I don't want to take the engine apart. The most I'm gonna do is take the risers off the manifolds and the thermostat housing.

Thoughts and opinions?




1986 Mercruiser 260hp V8 5.7L

 

[agallant80]

Re: Rust in cooling system

I think everyone has rust in their block. I am assuming you just took her out of winter storage and the rust you are seeing is what was generated from sitting over the winter. You should get a small screw driver or peace of coat hanger and ream out the drain holes, the rust and clog the drain holes and leave water in the block.

 

[Bondo]

Re: Rust in cooling system

Ayuh,.... Cast Iron, + Water, = Rust,....

Every time ya drain it, yer gonna see rust,...

That's the Whole point of pokin' the drain holes clear,....

After runnin' all season, yer gonna see rust, dirt, sand, 'n a host of other crud flowin' outa the holes,...

 

[acdc96]

Re: Rust in cooling system

Yeah I know I clean out the drain plug holes after every engine startup on the trailer. When it was in the water (5 years ago in saltwater) I would drain it monthly.

Should I keep an eye on the temp gauge when I put it in the water?

 

[Bondo]

Re: Rust in cooling system

Yeah I know I clean out the drain plug holes after every engine startup on the trailer. When it was in the water (5 years ago in saltwater) I would drain it monthly.

Should I keep an eye on the temp gauge when I put it in the water?

Ayuh,.... As with Any mechanical creature, you should have one eye on the gauges, at All times when runnin',....

 

[agallant80]

Re: Rust in cooling system

I am always mindful of the temp gauge but with that said you are not describing anything out of the ordinary here.

 

[Scott Danforth]

Re: Rust in cooling system

its a raw water cooled motor motor ran in salt water, now in fresh water - yes you will find rust. you will also probably find sand, rocks, small fish, bugs, twigs and anything else that was sucked up by the raw water pump and circulated thru the motor.

yes you should keep an eye on the gauges, just like the gauges in your car or any other mechanical devise

 

[Quickengine]

Hi I know it’s normal to have rust but I removed the water pump of an engine that has been sitting for manny manny years and the amount of rust I got is well a lot the engine spins I haven’t ran it yet because I wonder or it is dangerous to run it because maybe the engine can’t handle the force anymore here is a picture not the best I know but of the cylinder behind the water pumped

 

[QBhoy]

Always happens to an engine that’s been winterised and left empty over the years.