Another 3.0LX overheating

I

IcantDo55

Petty Officer 2nd Class
Joined
Jul 6, 2004
Messages
112
1995 3.0LX
No thermostat.
Elbow and manifold is only 3 years old and has been in water maybe 6 times.
Runs great.


1st trip of season and it ended us on beach overheating.

Ran on hose fine.
Left dock at high idle and putted through channel and in about a mile it crept up to almost 200 and I shut her down.
Pulled long hose from transom and started it and holding hose up we have 8-10" of flowing water at idle. Not impeller.
I have NEVER ran a thermostat (20 years) in a 3.0 motor and I know it runs 120 normally and maybe 160 at full speed.
Thermostat housing very hot to touch, large hose to circulation pump very hot but smaller hose to exhaust not hot.

Thoughts?
 
Bondo

Bondo

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70,524
IcantDo55 said:
1995 3.0LX
No thermostat.
Elbow and manifold is only 3 years old and has been in water maybe 6 times.
Runs great.


1st trip of season and it ended us on beach overheating.

Ran on hose fine.
Left dock at high idle and putted through channel and in about a mile it crept up to almost 200 and I shut her down.
Pulled long hose from transom and started it and holding hose up we have 8-10" of flowing water at idle. Not impeller.
I have NEVER ran a thermostat (20 years) in a 3.0 motor and I know it runs 120 normally and maybe 160 at full speed.
Thermostat housing very hot to touch, large hose to circulation pump very hot but smaller hose to exhaust not hot.

Thoughts?
Click to expand...

Ayuh,.... So pull some more hoses, 'n see where the water goes, or don't,....

Yer Nuts not to be runnin' a T-stat in any marine motor,.....

Marine T-stat housin's are much more complicated than that of a car,....

It not only feeds the circulatin' water pump, but the exhaust,....
Too much or too little or the wrong way, 'n ya got problems,...
 
achris

achris

More fish than mountain goat
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May 19, 2004
Messages
27,468
I completely agree with Bondo. No thermostat is a very bad idea. As well as not being able to direct the water the right way, the engine doesn't get nearly warm enough to boil off impurities in the oil, or for the pistons and cylinder walls to expand to their DESIGNED size and shape. Excess wear will ensue.

Chris..........
And get a thermostat in that engine, please.
 
I

IcantDo55

Petty Officer 2nd Class
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Messages
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Ok I have been reading and I agree, you are right and it should have had a thermostat. The thermostat housing is way different than and automotive one. But the question remains, It has NOT had one for over a decade and ran great. It ran 120* at low speeds and 160 at full throttle. But 1st time out this year its getting hot. What changed? Where do I look? I know putting a thermostat in now is a good idea but its definitely not going to help me some the issue.
 
Bondo

Bondo

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Ayuh,..... 1st thing I do in any over heat situation is to rebuild the raw water pump,......

Then track the water flow from there,....
 
I

IcantDo55

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Bondo , with the motor idling it put out a 12" stream of water straight up from the long hose feeding the t-stat housing. I think the raw water pump is fine.

I removed the riser and 3 years old and it was in crappy shape. So I replaced that and circulator pump, t-stat and all hoses. Also looked at flapper as some said for a restriction and I found one. LOL well a picture says a 1000 words. How can some people consider themselves mechanically inclined enough to work on anything!





[FONT=Helvetica, Arial, Verdana, sans-serif]Other issue I have is the water pump pulley is so close to the motor mount its hard to squeeze the belt through there. What causes this?


[/FONT]
 
achris

achris

More fish than mountain goat
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The pulley/mount clearance is just part of the design. The only way to change the belt is to support the engine at the front, remove the port side mounting spacer and slide the new belt in. I recommend while it's in that state, slip a second belt in as a spare. Once the support piece is back in, just tie the spare belt back.
 
I

IcantDo55

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Messages
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Ok so this week I replaced the:
Circulator pump
All hoses
Thermostat
Riser/elbow

Put it in water today and let it idle 30 minutes no problems. Drove it 1/2 mile at part throttle it heated back up. Got to 220 and I went back to idle and it cooled right down. All tempatures have been verified with heat gun and gauge. Cooled down and went full throttle and it heated up again in 1/2 mile. Let it cool and went again and it moved to 140* and stayed there for 5 miles at WOT. Put a total of 20 miles on it today mostly at WOT and it never went above 150*. What changes that fixed it? Could I have blown out some kinda blockage? Should I expect more issues or think its solved?
 
achris

achris

More fish than mountain goat
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IcantDo55 said:
... Could I have blown out some kinda blockage? ...
Click to expand...

Until this line, I was going to suggest that the symptoms sound very much like a partial blockage in the manifold or elbow. So yes, you could have blown it through. Could it come back? Anything is possible.
 
I

IcantDo55

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So is there a good way to "pressure" wash inside of block? I can only imagine that after taking off the hoses and seeing the chunks of rust in there the block must be filled with it. Can I remove thermostat and hook up a garden hose to the feed to the thermostat housing and run water through it?
 
I

IcantDo55

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Well 2nd on water test a complete success. I guess what ever blockage it had is gone. Runs great!

Thanks!
 
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