Water Heater Leak

[Stu Jackson]

Just in relationship to your pre-1930 Mark I diagram.  Sure been makin' C30s a loong time.    They had sails and engines back then?  :D:D

Rego Park...wow...long time ago in a galaxy far, far away...

[KWKloeber]

Stu,

Non comprendo, Senor.  "1930"?
Sorry, tonite I am particularly dense (not to mention CRS), you're gonna hafta humor me here?


-k

[Hawk]

Thanks Guys. Ron, I'm sure the hoses are clear. I can get immediate liquid out the other end when I put some in.

I'm picking up a thermostat and gasket tomorrow from a Kubota dealer. Ken your new tstat part number was bang on, but they said the gasket part number is now 16264-73270. May want to check that in the USA.

Happily the two bolts came off easily. The tstat has a whitish substance covering the top 3/8ths in. Who knows.

I take it I can drop the new one in the housing filled with coolant, and put the new gasket on. Do I use any gasket goop or no? Then burp again?

Thanks!

[KWKloeber]

Tom

My distributor still shows 16851-73270 as good.  16264-73270 is also good.  I have seen different p/ns of the same item when they are on different equipment.   Your number may just be a "same as."

No goop, just clean surfaces.  Re-burp. Cross fingers.  Pray to Neptune while sacrificing a virgin on the bow.  Oh no, that's renaming.  Sorry.

-k

[Ron Hill]

Tom : Just because coolant will come out the other end when added, doesn't mean that the lines are COMPLETELY clear - blow thru it and then you can tell!!

A thought

[Hawk]

Still at it with a twist.

The thermostat went in fine and appears all well when at lower rpms.
Today I noticed that in gear when put to full throttle the rpm is max 2200. Way lower than normal. Then in neutral it will go as normal up to about 3,000. I checked the throttle assembly and cable at the engine and the little locking nut was loose but I'll have to really assess what going on.

I did see a similar thread here  http://c34.org/bbs/index.php/topic,1704.msg9198.html#msg9198

AND I still experienced the temp moving steadily past 180 when I had the throttle at 2000 rpm which I realized was near the max on the throttle lever (in gear not in neutral) So I've got two non-normal things going on with my departure date looming):

IDeas welcome.
Tom

[J_Sail]

Total shot in the dark, and I may be way off base, but I recall an incident from decades back of an engine that overheated and produced insufficient power that ultimately turned out to be exhaust manifold obstruction. The exhaust gas back pressure both reduced the power and increased operating temperatures under load.

[KWKloeber]

Tom

Did you check the actual temp w/ a zap thermometer?
Did you check the hx and other stuff suggested?

i feel a plane ticket may be your saving ticket.  Ha!  I have my passport and everthing!  d:-0

-k

[Hawk]

Thanks guys. I'll have to keep working on it...Ron's suggestion and checking the HX. The thing is that all this started after replacing the water heater, which turned out to be the easy bit.
Ken,

Where would I check the temp on the engine when I find a zap thermometer?

Tom

[KWKloeber]

Typically at the tstat cap but you can hit it different places.
A non contact thermometer at Harbor Freight or online.

[J_Sail]

I own both of these and both are good.  Bought first one in 2014 for $16 for engine and other uses, and it's still serving me well. Bought the second one for $26 a few months ago for HVAC and other stuff at our offices where I needed a narrower "cone" of sensitivity for reading things at a greater distance - also good. For engines, the first one is fine.

https://www.amazon.com/gp/product/B006V4WNYU
https://www.amazon.com/gp/product/B00K5QVBCU

[Hawk]

Thanks guys,

I guess another test would be to run the engine up to the rpms where the temp was rising past 180F with the new thermostat removed??

Does that make any sense?

Tom

[KWKloeber]

IIWMB I wouldn't.  Don't know what that troubleshoots or proves. 

I would find the cause and take care of it.

What will taking the tstat out do as far as isolating the cause? We know it will run cooler with no tstat.

But if you're looking for a temporary quick fix for the excursion, then I'd consider that if you can't isolate the cause before then.

-k

[fatamorgana]

I can't remember if you said you checked the hoses going to and coming back from the water heater?  It took a lot of screwing around to get the air out of my system after replacing the hoses going to the water heater from the engine.  I knew it was finally burped when the hose coming back from the water heater was warm to the touch.  Before that, it stayed cool.  Just a thought.

[Hawk]

Yes thanks, I have immediate flow in the loop through the WH and have several times repeated Stu's method. All hoses that should be hot are indicating coolant flow.

The latest on this yesterday is that for good measure I checked the HX inlet which was clear. I cleared the raw water seacock inlet again which seemed fine ( and the exhaust water discharge has always looked fine).
I burped the system Stu's way and then by running the engine without the manifold cap and revved it up a few times.
Replaced the thermostat 2 days ago with a new 160F which seems fine.

But here's the rub as I mentioned before. I can run the engine in neutral up to 27/2800 yesterday for 15 minutes and the temp is happily sitting at about 165F. BUT when I put into forward gear I can only get the rpm to 2200 with full throttle. AND the temp starts slowly increasing over 10 minutes past 180F+.

Yes, I double checked and marked the throttle linkage location when at full throttle in neutral (2800 rpm) and then again when in gear (maxed out 2200). The linkage was in the same position when at full throttle in neutral and in gear but the max rpms were very different as above.

So it appears that the cooling system is working and I can run at high rpm in neutral with steady 165F. BUT now when put into gear I have diminished RPM in gear and increasing temps.

I have not yet jumped in the water to check the prop. Murky water. But could I have picked up something around the prop coincidentally? I presume that could reduce rpm and cause the engine to work harder?WILL CHECK THIS.
I have not yet changed the two fuel filters. changed them two seasons ago. WILL DO THIS. Could there be an issue with reduced fuel?

The key issue now seems to be why would the engine purr along with cooling fine in neutral at high rpms BUT have immediate diminished RPMs from a max 2900 when in neutral,  down to 2200 with throttle at full AND then the temp begins to increase toward 190 and 200F over about 10 minutes??

Sorry to keep coming back on this guys. I'm at bit of a loss. The water heater replacement went just fine but now this............boats!:)

Keep your thoughts coming ...they are really helpful.

Hawk