Flushing a 2003 3.0L. Thermostat out use CLR or other

[schiker]

Boat runs a bit warm and stat modulates and seems slow to react. I had just changed impeller. So decided to change the stat. Looking at stat housing and stat it is slightly corroded, rusty, and scaled. Should I pour some CLR in block then flush out winterizing hoses or other flush treatment??

Boat is fresh water only and had 160f stat but original owner might have run it in brackish water in Florida. It has sat for 2 yrs just getting back in to boating.

 

[schiker]

Re: Flushing a 2003 3.0L. Thermostat out use CLR or other

I found and bought some stuff called salt & corrosion terminator and it has a hose mixer. Its suppose to remove scale and build up from old salt corrosion.

I think mine is more rust from fresh water though. Salt Terminator says "Not just for Salt Corrosion"!

What are some opinions?

 

[Bondo]

Re: Flushing a 2003 3.0L. Thermostat out use CLR or other

Ayuh,.... Post a Picture of what yer Lookin' at,... Can't see it from here,...

I'm guessin', there ain't any problem,..... Rusty ain't All bad,...

Cast iron needs it's patina,... Yer not lookin' for grey metal,...

 

[schiker]

Re: Flushing a 2003 3.0L. Thermostat out use CLR or other

I wish I would have taken a picture. When I took the thermostat out I stuffed a rag and half down the thermostat hole so I could scrape the stat gaskets and clean neck out and it wouldn't go down the big hose. There was scale/crust shelf below the big hose on right side of engine. I could easily position a rag to clog up the hole. I did not see down in the block. I thought it was casting as it was rust colored like rest of block. I think there was a hole a bit bigger than stat spring but it wasn't wide open for sure. Any way I scrapped it clean and used a shop vac to clean out the crud. The second rag must have pushed the first rag through the crust because when I pulled the rags out I thought wow that's more wide open and I could see the temp sending probe easily and did not see it before.

I did use a little CLR on a rag to clean the temp probe and around the neck to clean it to make easier to install the spacer. I installed the new stat and temp rose to 170F and held steady on the muffs. Before it would range a bit from 170 to 180-185 ? F

I hope to take it to the lake tomorrow to see how it does. I'll try and post a pic of the old stat but its not really showing anything much.

I posted originally from my phone on way to run an errand.

 

[schiker]

Re: Flushing a 2003 3.0L. Thermostat out use CLR or other

Here is pic before stat came out. It doesn't show the real blockage I just took it to try and note spacer orientation if I could or needed later.
Second pic is old stat. Nothing bad but do wonder if the scrape mark is short like it wasn't opening all the way.

I think guess the crust kept the water from circulating around the stat like it should. Really wish I would have gotten a picture.

 

[schiker]

Re: Flushing a 2003 3.0L. Thermostat out use CLR or other

Took it to the lake and it seemed to run a little cooler 5-10 degrees F. It also did not spike to as high of temp before coming back down. The boat was ~400 lbs lighter though w/o whole family and extra gear. May have gotten by with the old stat but feel better now.