Thermostat, Gauges & Cooling system.

[jimmyrobby]

Alright more questions, I thought I´d separate them so they were more topic specific.

So I know the Gauges in the Patrols aren´t known for their accuracy, but I´m not getting a lot of movement in them. This doesn´t worry me so long as it´s just relatively unresponsive gauges rather than broken ones. Really the only one I´m worried about is the Temp Guage/thermostat. Don´t want to overheat without having any prewarning

I know the Amp meter isn´t expected to move. The Fuel Gauge says full at 3/4, I can work with that. The Oil Pressure certainly changes before settling back at Low. The Water Temp moves just a bit above low, but only barely and I don´t know if that´s simply because the ignition is on. That´s what worries me. Does that seem normal? I noticed in a much older post about boiling water in a pan and then taking out testing the thermostat / Temperature sending unit --they are the same thing right?--, I´ll give that a try anyhow.

The Patrol Never seems to run too hot, Which makes sense to me since it´s basically had an engine overhall and the cooling system seems in pretty good nick. I´m just trying to preempt any potential problems really.

Thoughts?

[bosque]

JR,
That thermostat check is very logical and easy with a separate thermometer in a pan of water. When it reaches 170 or so you should see the device expand or contract/ open or close.
The termostat is above the water pump inside a roundish cast housing (see parts or service book to study. sorry I'm not home to check for a better description).

[Esteban]

JR,
That thermostat check is very logical and easy with a separate thermometer in a pan of water. When it reaches 170 or so you should see the device expand or contract/ open or close.
The termostat is above the water pump inside a roundish cast housing (see parts or service book to study. sorry I'm not home to check for a better description).

Maybe there isn't a thermostat inside! It is typical down there to take it out. If in fact is missing one, install a 170°F (76°C) You'll be traveling a big percentage in the highlands, above 2000 meter above sea level (6500 ft). At that altitude you need to lower the thermostat to avoid boiling the water at a lower temperature and the pressure buildup that results. Put a good antifreeze at this time. It will help a lot in preventing some overheating.

The ampmeter will show some movement immediately after you start the engine, since the battery was drained a bit during the start. But after that, it remains almost at the middle. At a shop they can measure the volt output of the system with the engine running. It should be around 14.5V.

Also, at a shop, they can probably put an oil pressure gauge to check how the engine is behaving. There are about 5 plugs on the side of the engine where the oil filter is located. Any of them will serve to tap an external oil pressure gauge. With the engine hot, pressure should be around 15 psi at idle, and close to 50 psi at 2000 rpm.

[RiverPatrol]

...the thermostat / Temperature sending unit --they are the same thing right?--

They are not the same thing. The temperature sending unit is a little cylinder that fits into the lower part of the thermostat housing, with a yellow wire coming from the left (alternator) side of the engine attached to it.

[jimmyrobby]

Maybe there isn't a thermostat inside! It is typical down there to take it out.

Right on Esteban! You're on the ball! I haven't yet taken apart the thermostat housing to actually check but I started the engine with the radiator cap off to see if there was any water movement before it had heated up to operating temperature, and lo and behold: water movement as soon as engine started. So we can direct blame at the non-existent thermostat for the cooler operating temperatures, or at least if there is one it's not working properly...

I did also let the engine heat up and then disconnected the temperature sending unit (thanks River) to see if there was movement in the gauge. It was slow and small but there was at least a tiny bit of movement. So I'm just assuming the engine is running at a lower operating temperature than preferred for now, we'll wait until after installing a thermostat to check. You never know, could have no thermostat AND a bad temp sending unit....

Although It also appears that there isn't much, if any actual coolant in the radiator. Looks mostly like water with a little rust coloration (I blame the bad mechanic). Don't know, but I'll get around to flushing it and adding good coolant anyway. Had a quick look for the drain plug in the radiator, it didn't stand out. Is it hidden somewhere or should I just disconnect the lower radiator hose?

[Esteban]

Jimmyrobby,

Little by little your getting to know your Patrol. It will proof very valuable during your trip. Good observation about the water movement in the tank!

To drain the radiator, there's a petcock at the rear of the radiator, bottom tank. It's block from the view by the fan shroud. But if you think the water is dirty, taking the bottom hose will aid in flushing it with a hose and running water from the top.

Also, the petcock for the engine block is next to the starter motor. If some rust have develop, no water will flow from there, and you'll be better taking the whole petcock out and working with a wire (from a clothes hanger) and digging through the blockage.

Difficult to asses the temperature without a thermometer, but when the engine has been running for while, can you grab the top hose without burning yourself? If the water is below 60°C (140°F) you can grab the hose.

Hope you can find the coolant. Prestone is probably available.

[Esteban]

...To drain the radiator, there's a petcock at the rear of the radiator, bottom tank. It's block from the view by the fan shroud. But if you think the water is dirty, taking the bottom hose will aid in flushing it with a hose and running water from the top...

Sorry about that. It's at the front of the radiator, more or less opposite to the bottom outlet.

Radiator Petcock.JPG