Such thing as a "weak" water pump

[al m]

My g2000 is running warm,has got progressively worse over time. Engine runs well doesn't smoke or burn oil,coolent level is normal and rad screen is clean.

 

[Daren Todd]

You say radiator screen is clean. But how is the radiator fins themselves?

Dust, dirt and grease, can build up on the engine side of the fins and clog airflow causing similar symptoms.

I have had the impeller in a water pump wear out before, so it doesn't move the water like it should. But that is extremely rare. Most of the time the bearings fail before the impeller.

 

[al m]

Washing out the rad with a hose only make a marginal difference in the amount of time I can mow before approaching the red zone,and yes ,it's hot,not the gauge

 

[Blondie70]

Might as well take the bull by the horns....take the radiator out and bring to radiator shop for cleanout.....while you're at it....replace the water pump. All problems should be solved for many years as far as the cooling system is concerned.

 

[BruceP]

I have G5200 tractor with similar engine. Mine was also running on the warm side. Before going thru the trouble of removing radiator and other items... I used off-the-shelf radiator flush and mowed for several hours with that stuff in there.

I captured the first two drains into container... it came out RUSTY BROWN. After sitting for several hours, it settled into a layer of rust from inside the block.

Follow this with several more drain/rinse/run with tapwater.

The final two rinses should be with DISTILLED WATER and mix your fresh antifreeze with DISTILLED water too.

For me, that radiator-flush has improved my engine temperature enough so I did not have to do anything else.

Hint: When draining cooling system, open both the radiator and block drain and use leaf-blower into radiator cap to force more fluid out.

ALSO - You did not mention the thermostat... have you removed it and given it the hot water test? (put into water alongside a thermometer and heat on stove while observing operation ) Make CERTAIN that it opens all the way at the specified temperature.

 

[al m]

The rad flush is s good idea,can't hurt in a machine of this age. I seriously doubt a thermostat issue,it's a slow gradual rise in temp ,takes a hour or more to climb to a worrisome temp. A stunt thermostat would show high temps much sooner,or a cold running engine, always dramatic one way or another. This is a slow developing issue,worse on hotter days,that's why I'm eondering about the pump,but don't know what the impeller is made of. A rubber impeller will show these symptoms, a solid one works,or it doesn't,no real in between

 

[al m]

So this morning I took Bruce's advise and installed a flush kit and followed the directions .Amazing what comes out! Also took the time to clean the rad and screens again,while in there with the hose cleaned some crude off the engine and removed the guards from the deck and cleaned out there as well. After filling up with fresh prestone fired her up and got down to business mowing. Temp gauge came up to the first graduation,then stayed put. Mowed the entire lawn without it moving any more. It's never ran this cool in the ten years or so I've owned it.
Thanks to all who took time to reply

 

[Tooljunkie]

Great that you solved it, but i would like to add, if it is equipped with a thermostat, its there to regulate temperature. More often than not, thermostats fail in the open position.this does not necessarily mean it will run cold,but it will gradually heat up to the point where it will overheat. When a thermostat is closed, it allows coolant to pause in the rad where it cools. Then thermostat opens and allows cooled coolant into engine.as soon as thermostat sees the cooler temp it closes creating a cycle of open/close. This cycle is dependent on an efficient or proper operating cooling system.

Of course the exception to the rule, here in the deep dead winter a stuck open thermostat would never allow engine to build heat.

Did have one stuck closed in winter, heater core was enough to keep car from overheating,heat was great.

 

[GeoHorn]

As a young automotive mechanic working for Toyota (graduated from their technician school at Gulf States) I was taught that thermostats are designed to fail in the OPEN position.

I've now replaced over a dozen failed thermostats....and EVERY ONE OF THEM failed in the CLOSED position causing severe overheating! Every one!

Thermostats are made with a capsule of alcohol which, when heated, expands and forces the Thermostat to open against a spring ...that spring being designed to keep the thermostat closed until the alcohol heats/expands. A failed/leaking capsule (usually due to corrosion) will never open the thermostat.

I have no idea why we were taught they'd always fail in the open position because that has never been the case in my 40 years of mechanical experience, and I have never seen a thermostat with a fail-safe design.

 

[Dave_eng]

My g2000 is running warm,has got progressively worse over time. Engine runs well doesn't smoke or burn oil,coolent level is normal and rad screen is clean.

Know Smiths Falls well. Don't run without a thermostat. Serious winters!!

From 1999, Managed the facilities for the Upper Canada School Board and had several Smiths Falls schools in my portfolio.

In more recent times, was buying medical marijuana from the organization set up in the old Hersey Chocolate bar factory.

Glad BruceP's advice helped.

Dave

 

[torch]

Water pumps rarely fail to pump coolant. The normal failure mode is to start leaking at the seal.

I would try flushing the entire system, using a good quality radiator flush and following the directions religiously. This usually involves draining and refilling with water several times.

As for thermostat failure, I don't know of any that will fail open unless the frame physically breaks, releasing the spring pressure.

There is a design out there called "fail safe" that incorporates a second spring mechanism. If the system overheats (as when the primary system fails closed) the second mechanism forces the thermostat open and latches it in place. Motorrad is one manufacturer.

 

[North Idaho Wolfman]

He fixed it already!