Ok, What are my chances on cleaning up salt plugged block coolant passages?

[BrentEB]

I've been fighting an engine overheat problem for a couple months now. All the usual washes, ect, really didn't do a thing. Dropped the exhaust manifold and the only plug is in the engine block. MR1 110hp. Pulled the anode assembly, completely plugged with salt. Geez. I've rigged a "drill" from 3/32" vinyl coated multistrand wire stripped at the end that seems to get in there. 12" length now, but going up as it pretty easily goes through the salt. Just started that today.

This was not a "neglect" problem as I washed on the hose after each outing. I attribute it to the "hose" flush design - there is not enough water pressure to get through the check valve for a good block flush because of leak back through the normal inlet. I have manual valves to close off that leakage for hose flushes NOW.

If I get a flow established versus a dead head I think the problem will be licked. What does experience say? Do I have a chance?

 

[Beachbummer]

Others have succeeded. No reason to think otherwise for yourself.

Look through the old threads, some have disconnected exhaust and looped chemicals to help dissolve the salt. A problem understood is half solved. It's not a matter of if, but how. Best of Luck!!!!

 

[swatski]

This may help for some discussion of the issue:
https://jetboaters.net/threads/closed-loop-flush-of-mr-1-with-marine-descaler.8443/ but I must say a 2013 is a very young age to develop those kinds of problems...
I'll be moving back to the coast and not looking forward to (inevitable) flushing nonsense.
My biggest worry now will be cracking in passages with trapped water in cold climates.

--

 

[Gym]

I have used Limeaway to clear out my passages. Try to use it undiluted. After you run it through let it sit for 20 to 30 min. Then flush it out with fresh water.

After you resolve this problem you should use a product like Salt Away. Regular water flushing will not remove all the salt.

 

[Dixie Highway]

Any low pH solution will dissolve salts, just be mindful of the interaction with rubber and EPDM in the cooling passages. Heat could help, the closed loop idea is the best one as you can really keep the chemical working hard in there. Even a warm vinegar solution is better than straight water. Citric acids are mild enough you wouldn’t have to worry too much about it. I’d avoid anything strong, hydrochloric, muriatic, or sulfuric unless you have experience mixing and using those. Lots of aluminum in our engines. I use them all the time but wouldn’t run it through my boat except as a last (as in the next step is engine replacement) resort.

 

[BrentEB]

Thanks for the replies. Since the inlet/outlet on the block are both blocked a true circulation isn't in the works. I'm looking at adding a higher velocity stream into the passage with outflow back through the concentric area. Tried several hours of just water which really didn't do much upon inspection. So I'm going to use a fountain pump with sulfamic acid and some salt away in the same configuration, but go at the inlet and outlet at the same time. Those lines will drain to a collection pan with the pump. Charge it up and let it run until the pH rises and density plateau's, then replace with fresh water & acid and start again.

The pump and a hydrometer are leftover from old brewing and water cooled computer hobbies... Haha. This should eventually break through the salt. Apparatus up and running maybe tomorrow.

My determination as to the cause of the salt blockage is:
1) Low cooling water flow (pressure) when attempting to flush the engine 'on the hose'.
i) Water back-flow out of the cooling inlet line limits the flow through the engine. I've installed valves in the lines as seen searching earlier posts
on this forum.
2) The check valve in the cooling water line to the block.
i) the extra pressure drop across the CV may prevent flush water from entering the block passages. Add valves per 1).
ii) The CV prevents liquid in the block passages from completely draining after flush. Steam CAN escape so the salt concentrations in solution
increase, then the salt precipitates out when the engine cools. I don't know why Yami didn't want the crankcase coolant to drain, meh. Again,
the valve installation in 1) seems needed to insure a flush flow.

Didn't intend to be so long winded but it's bugged me of late.

 

[suke]

Dad gum! Take pics as you go along for us dunces. Hard to really picture your solution. I boat a few times a year in salt.

 

[Liveto99]

Wear safety goggles

 

[buckbuck]

@BrentEB Can you please take some pictures of the check valve that is preventing the water from draining. This is the first I have heard of this and I want to understand.

 

[BrentEB]

@BrentEB Can you please take some pictures of the check valve that is preventing the water from draining. This is the first I have heard of this and I want to understand.

I couldn't really access anything on the starboard side of the engine without dropping the exhaust manifold. Here's a pict along with the cooling water hose diagram.

 

[swatski]

I couldn't really access anything on the starboard side of the engine without dropping the exhaust manifold. Here's a pict along with the cooling water hose diagram.
View attachment 109936View attachment 109937

I had thought that was a T-connector, not a check valve... huh!
did you have a chance to inspect it?
I wouldn’t hesitate to use one in my wakesurfing ballast plumbing, not sure how I feel about one in the engine cooling line.

—

 

[Scottintexas]

@BrentEB
in your schematic Do you think #7 is also a check valve ?

I'm also confused by this, in my '07 manual it only lists it as a "joint", I certainly wouldn't argue something has changed, just wondering,

my '07 diagram,

 

[BrentEB]

@BrentEB
in your schematic Do you think #7 is also a check valve ?

I'm also confused by this, in my '07 manual it only lists it as a "joint", I certainly wouldn't argue something has changed, just wondering,

my '07 diagram,
View attachment 109938

Part #7 in the diagram I posted is definitely not a check valve, although both parts are labeled "joint". The one in your diagram probably not either ONLY because there's no blow-up for the part that shows the arrow. But just an assumption on my part.

I'm working off a 2006 Service Manual. While generally very close to my 2013 boat I have found a couple differences and one glaring error. The temperature "spec" for the exhaust thermoswitch is about 10 C lower than the (incorrect) temperatures shown in the calibration check procedure. That little error cost me about a month and a new unneeded switch. Thanks Uncle Yami

 

[Scottintexas]

I would also mention, my diagram is for a '07 MR1-HO motor,

I checked the 05 HO manual I also have and it shows the same diagram, so the non-HO motors must have different routing,

 

[BrentEB]

Here's another tidbit I'm posting because I was unaware of it and alarmed at what was found. Came across a reference for the anode in the block cooling system 2 weeks ago. Pulled it out and the cavity was plugged with salt. Not really hard salt, but plugged. Nothing inside the holder but salt and about 3/8" of threads. The replacement assembly finally arrived and WHOA, the missing anode was pretty large. No pict of when pulled out so imagine no shiny anode! Here's the new one and location. Now let's see if it's possible to replace one the other engine without removing the manifold. Thanks Uncle Yami

 

[Beachbummer]

When you go at it next time, can you take another picture of the location further away? It would help to understand fully where it is.

Thanks!!! Great find!

 

[BrentEB]

When you go at it next time, can you take another picture of the location further away? It would help to understand fully where it is.

Thanks!!! Great find!

Nope - no room. Look at the pict in post #10. This is all under cylinder #4.

 

[buckbuck]

Here is what they look like in an old 2008 boat with the MR-1 engine.

 

[Beachbummer]

Is cylinder 4 the one closest to bow or stern?

Thanks again

 

[buckbuck]

Stern. It is close to the oil cooler.