Rust build up

[dobler5]

I got a boat engine that has quite a bit of rust build up in it in the water pathways throughout the engine. Its causing me cooling issues on the water. This isnt surface rust on the engine walls may I add. This engine has been is saltwater which is half of my problem. What is the best way to get rid of this build up? Any products i can run through it that will eat it away? Thanks for the help!

 

[dobler5]

Re: Rust build up

Whats shoes have anything to do with boat engines>?

 

[Todd157k]

Re: Rust build up

not sure what that website has to do with this post.. w/e


anyway, I use a really good rust remover on smaller parts when rebuilding my 67 triumph. The name of it is... Coke! lol. Yes, it works VERY well on rust however I think your problem is a bit beyond it's capabilities.

 

[HT32BSX115]

Re: Rust build up

I got a boat engine that has quite a bit of rust build up in it in the water pathways throughout the engine. Its causing me cooling issues on the water. This isnt surface rust on the engine walls may I add. This engine has been is saltwater which is half of my problem. What is the best way to get rid of this build up? Any products i can run through it that will eat it away? Thanks for the help!

Howdy,


Well you might be a little more specific. Is this rust in the cooling passages in the block, head, intake/exhaust manifolds and risers?

How old is the engine, manifolds and risers?

 

[dobler5]

Re: Rust build up

The rust is in the engine block alone. I already replaced the exhaust manifolds and the risers. Somehow I need to find some product I can either flush through the engine or something to eat it up so The engine block will get cooled not the rust.

 

[HT32BSX115]

Re: Rust build up

That will be fairly risky.
Usually when the rust build up is such that it's clogging passages (in either the block, manifolds or risers), That is an indication that they should be replaced.

It's risky in manifolds and risers block etc.... because the rust is actually the manifold/risers themselves! (it's just that it reacted with the salt/water/oxygen......IRON OXIDE)


You should replace severely corroded parts because you do not know how thin the walls are. You should absolutely NOT use acid or other mechcanical means to remove the rust because you expose the rest of the metal that has not corroded yet.......AND you won't know how thick or thin the rest of it is.

Attempting to "clean" and use old rusty manifolds and risers on a new engine is even more risky because you can destroy the expensive new engine.

Doing this with an older otherwise reliable engine ( assuming that it is reliable) will put you at risk of an engine failure at the most inopportune time.....Like "near the rocks" etc..... [Murphy's Law]


You should replace the engine.





Regards,


Rick

 

[dobler5]

Re: Rust build up

My rust build up problem isnt that its blocking the passages. Its just that the engine itself cannot get cool enough over long period of times of use. Is there anyway of tackling this problem without replacing the engine block itself?

 

[HT32BSX115]

Re: Rust build up

My rust build up problem isnt that its blocking the passages. Its just that the engine itself cannot get cool enough over long period of times of use. Is there anyway of tackling this problem without replacing the engine block itself?

Did you:

1. Replace the raw water pump?
2. Clear any (impeller fragment or other debris)blockage in the raw water circuit (including raw water pickup to all hoses, oil coolers, t-stat housing, etc)?
3. ENSURE that the intake/exhaust manifolds/risers are ADEQUATELY free of obstruction (RUST) in the cooling circuit?
4. Circulating pump passages are clear of rust and corrosion?
5. block and heads are clear of rust and corrosion?

MOST engine over heat problems are due to #1 to #3

The block and heads are usually the last places that clog with rust.

If they do, there's really nothing you can do except replace them.

You could disassemble the the engine and use acid to clear the cooling passages but how would you know if you had a "rust-though" that the acid opened up? The cast iron water jacket doesn't corrode at exactly the same rate everywhere and the wall thickness is not uniform everywhere in there either.

It's (sand) cast iron.

If the block is rusted inside enough to cause overheats. It MUST be replaced.

Sorry about that.

 

[ifallsguy]

Re: Rust build up

Have you checked or replaced the thermostat?

 

[dobler5]

Re: Rust build up

It's my block that is rusted pretty good. Engine will run perfectly for a couple hours on the lake and than it will be full throttle for 10 mins and just slowly lose power and die. All will be done till it cools off. Its like there is a fuel vapor lock due to the engine gettin so hott. Raw water pump, exhaust manifold, exhaust elbow, circulator water pump, thermostat are all band new.

 

[Alpheus]

Re: Rust build up

Im thinking its something else other than just rust. Remove all of your hoses,manifolds,risers and check for a blockage. Dont forget the power steering cooler...

 

[dobler5]

Re: Rust build up

Already have done all that. All im asking if anyone knows how to get rid of major rust build up on engine cooling walls...Is there any kind of product out there meant just for that? Probably not. Gonna go with a new engine.