I don’t care how often you flush

[pstephens46]

I think that most are. Yet, they are still problematic as evidenced by the number of posters with cooling and flushing issues.

My point was to inspect more often than the suggested maintenance interval for the
thermostats. As dictated by the owner’s manual.

[HMBJack]

With twin 250s should I be more concerned than my nonchalant service guy?

>>> Best advice I can give you is to inspect them annually. The salinity of your water and your use and maintenance characteristics are unique to you and your engines.
It's a relatively simple task and what you don't want is to lose your powerhead because you're not aware of what's going on in there.

[oldmako69]

takes 45 min to change/clean the t-stats on a 3.3. why not simply do it occasionally?

I think that most are. Yet, they are still problematic as evidenced by the number of posters with cooling and flushing issues.

[No Bail]

How is the best way to clean out the gunk in the T Stat hole? Are there solutions that can eat some of it out (higher % vinegar) ?

I had Yami 150's and used salt away but still had significant buildup. My service guy was not concerned.

With twin 250s should I be more concerned than my nonchalant service guy?

[BQUICK]

I was talking 10min for BOTH......haha

[pstephens46]

F150 takes about 5 minutes.

[BQUICK]

I only flush at end of season but flush with stats out. 10min job to remove them on my 89 200s. I notice that the flushing is more effective with stats out especially since I'm flushing in relatively cold weather so stats would never open or maybe just a little.
This is in brackish and salt water....I'd love to run WOT with stats out in freshwater to clean system out........

[HMBJack]

Just returned from my boat. Pulled all 4 T-stats from my two F250's.

Rodbolt was right - it took me exactly 45 minutes per engine to do the T-stat inspection (and I wasn't working fast BTW).

Another observation - in 160 hours of use since my last inspection, I noted NO salt crystal build up in any of the T-stat housings (yay!).

I attribute this to my practice of now flushing on the muffs in addition to the garden hose fitting. I previously ONLY used the garden hose fitting for flushing and - per the above nasty photo - on my boat that just didn't work.

That said, nothing replaces the annual inspection of the T-stats and the bores they sit in.

[HMBJack]

Rodbolt is exactly correct (as usual).

Just get out your 10mm with extensions and have at it.

I have an extra set of T-stats cleaned and tested to swap out. And If need be, I slap some oil based paint in there to keep things happy.

Flushing is over rated and is often a waste of time even though I still do it.

FYI - Here is what my T-Stat bore looked like after TONS of flushing w the garden hose fitting (I have twin F250's built in mid 2005):



And here are the painted frames of my T-stats to slow the effect of dissimilar metal corrosion:

[rodbolt17]

takes 45 min to change/clean the t-stats on a 3.3. why not simply do it occasionally?

[99yam40]

Deposits build a bridge between metal body of stat to the AL of the block.

actually I believe it is the copper or brass of the center part( temp sensing bulb) that is causing the main problem with dissimilar metal with the aluminum pitting.
along with the salt bridging between the two

[HMBJack]

I agree with you. That is one reason why I painted the frames of my T-Stats as a form of insulator to slow down the corrosion creep of dissimilar metals.

I don't know how to link it here but you can refer to a post by me on 3-8-18 titled "Somebody explain this to me: T-stats..."

No matter how much you flush, the T-stats of the 3.3 Liter engines will clog up with crap. At least that is my experience...

[pstephens46]

T-stat is rubber on metal anyway. So, no insulation/electrolysis issue. Right? Or am I smoking crack?

Deposits build a bridge between metal body of stat to the AL of the block.

[panasonic]

T-stat is rubber on metal anyway. So, no insulation/electrolysis issue. Right? Or am I smoking crack?

They don't have to be touching each other...just be in close proximity to each other. Take the rubber off the stat (if you could get it to seal somehow) and leave it in there for awhile...metal on metal and see what happens. I think you will have much more corrosion.

[oldmako69]

Polysulfide looks to be a caulk? Flexible?
Interesting as it may act as an insulator. Negating the battery effect I am getting that is eating the AL.

T-stat is rubber on metal anyway. So, no insulation/electrolysis issue. Right? Or am I smoking crack?