The Workhorse Isn't

[Frosty_s_Mom]

After being stranded in Las Vegas for two weeks, we are no closer to solving the overheating problem that left us at Findlay's with no solution to the problem. between this rv service and Swanty's in bullhead city AZ, we've replaced just about every part remotely connected to the cooling system, including at Findlay's a new radiator. we are barely making a mile to the rv park before overheating and obviously we won't make it out of the city. if the self-proclaimed #2 diagnostician in the country can't figure out why the temp is spiking after over $5,000 worth of parts-where do we go next?

[PaulJ2]

rgatijnet1 wrote:

PaulJ2 wrote:
Need some history here. Was it a constant problem that has gotten worse? Or did it just start to overheat suddenly? What parts were replaced for that money?
Can only guess without more information. Some details please.

Ok, see it overheats almost at once. Agree no water circulation.
Did they replace water pump with the wrong one? Serpentine belt driven pumps operate counterclockwise, v belt ones operate clockwise. They have been known to mix them up.

Usually I would rule out the water pump in this situation but you do bring up a good point. The GM engine is used in Marine applications which means they have CW and CCW rotation engines. Many GM water pumps are bi-directional but I guess it is possible that the wrong water pump was installed. A check of the water pump part number should confirm if it is the correct part.
Naturally you want to check oil pressure. A failed oil pump can cause things to get hot quickly.

Years ago I replaced a water pump and the part# on the box was correct but the wrong pump was in the box--was a rebuilt unit however. Been leary of that since. Impeller was angled the wrong direction. Stranger things have happened.

[rgatijnet1]

PaulJ2 wrote:
Need some history here. Was it a constant problem that has gotten worse? Or did it just start to overheat suddenly? What parts were replaced for that money?
Can only guess without more information. Some details please.

Ok, see it overheats almost at once. Agree no water circulation.
Did they replace water pump with the wrong one? Serpentine belt driven pumps operate counterclockwise, v belt ones operate clockwise. They have been known to mix them up.

Usually I would rule out the water pump in this situation but you do bring up a good point. The GM engine is used in Marine applications which means they have CW and CCW rotation engines. Many GM water pumps are bi-directional but I guess it is possible that the wrong water pump was installed. A check of the water pump part number should confirm if it is the correct part.
Naturally you want to check oil pressure. A failed oil pump can cause things to get hot quickly.

[jwmII]

Check the bottom radiator hose. It may collapse from the suction of the water pump. Replace it with a known new hose with a spring inside to prevent collapse.

[PaulJ2]

Need some history here. Was it a constant problem that has gotten worse? Or did it just start to overheat suddenly? What parts were replaced for that money?
Can only guess without more information. Some details please.

Ok, see it overheats almost at once. Agree no water circulation.
Did they replace water pump with the wrong one? Serpentine belt driven pumps operate counterclockwise, v belt ones operate clockwise. They have been known to mix them up.

[BobR]

427435 wrote:

rgatijnet1 wrote:
If the engine overheats in a little over a mile, that indicates that you are NOT getting water circulation. This eliminates the fan clutch, transmission, dragging brakes, etc.
I would look at things that will stop the water from circulating like a bad thermostat or an air pocket in the cooling system that will cause the water pump to stop pumping. Check the thermostat with a pan of hot water to make sure that it opens completely and that it is installed correctly, and not backwards. Fill the system with water and properly bleed it to make sure that all air is removed.

Good suggestions.

The bottom radiator hose could be collapsing or plugged. Make sure that there are new hoses in that $5000 worth of parts.

Check the hoses- If a hose has a tight bend it could cause collapsing. I have one vehicle where a spring the diameter of hose ID is inserted to prevent collapsing.

[Big_Katuna]

I would like to see the list of what they did for $5K.

You would think hoses, thermostat, fan clutch (or electric?), temp sensor and rad have been replaced. Is it losing coolant? Leak down test? bad ECM/ timing off? Crank angle sensor timing off? Head gasket?

Please keep us posted.

[427435]

rgatijnet1 wrote:
If the engine overheats in a little over a mile, that indicates that you are NOT getting water circulation. This eliminates the fan clutch, transmission, dragging brakes, etc.
I would look at things that will stop the water from circulating like a bad thermostat or an air pocket in the cooling system that will cause the water pump to stop pumping. Check the thermostat with a pan of hot water to make sure that it opens completely and that it is installed correctly, and not backwards. Fill the system with water and properly bleed it to make sure that all air is removed.

Good suggestions.

The bottom radiator hose could be collapsing or plugged. Make sure that there are new hoses in that $5000 worth of parts.

[rgatijnet1]

If the engine overheats in a little over a mile, that indicates that you are NOT getting water circulation. This eliminates the fan clutch, transmission, dragging brakes, etc.
I would look at things that will stop the water from circulating like a bad thermostat or an air pocket in the cooling system that will cause the water pump to stop pumping. Check the thermostat with a pan of hot water to make sure that it opens completely and that it is installed correctly, and not backwards. Fill the system with water and properly bleed it to make sure that all air is removed.

[Born_To_Travel]

Go find a real mechanic and take #2 to court...

[turbojimmy]

hanko wrote:
water pump?

I would hope that buried in that $5k is a water pump, and every hose, valve, tube and orifice that coolant flows through.

[hanko]

water pump?

[turbojimmy]

rjxj wrote:
Did they check the head gaskets or cracked head. You could probably have done a crate engine for near that money.

With the limited amount of information provided, this is my knee-jerk reaction too. Head gasket or head leak. The coolant needs checked for exhaust gas contamination.

Overheating problems are generally easy to solve. My experience has been that when they're not, a head or head gasket is to blame.

[azrving]

Self proclaimed may be the key point. We can only guess on here but there is no way in heck you should have spent anything near that amount of money. It cant be that hard to find. Parts replacers.

Did they check the head gaskets or cracked head. You could probably have done a crate engine for near that money.

[hanko]

newman fulltimer wrote:
did they ever check the transmission to see if it is the cause?

Might check your refrigerator also

[vjstangelo]

Also visit rhe irv2.com Workhorse Chassis forum.