Overheating saga

[rickv100]

I am still having issues with my truck overheating.

I have replaced radiator, thermostat (180 degrees), and water pump. Flushed block and refilled. All radiator hoses have been replaced. The temp gauge and fuel gauge are working fine so I do not think it is a gauge issue.

I replaced the fan belt and it is tensioned correctly.

It has been awhile since I filled it so I do not think that there is a air bubble but tomorrow I will jack up the front of the truck and see.

There was an issue with a dragging brake but that has been resolved.

I am going to let the truck run sitting in neutral to see if it overheats with no load.

I tested the thermostat in hot water and it opened at 180 degrees.

I am stumped at this point about what it could be.

Rick

[Lalo88DK]

Im out

[rickv100]

Lalo,

No, I am not sure. I measured the temperature by opening the radiator and using a meat thermometer in the coolant. I also measured the temperature when I tested the thermostat was opening.

I will try testing it again.

Rick

[cousindave]

Lalo88dk is right. Definately is the gauge. I just went through two months of scratching my head!!! I finally replaced with a mechanical gauge from sunpro and she barely reaches temperature. I should have known because Lr's aren't known for overheating.

[Lord Icon]

a little help with the sensors..

The pic posted shows an arrow to the sensor to the right of the neck, as looking at it from the front breakfast.
I also have a sensor on the left of the neck and just below...
I have the gauge wire connected to the second one and I am showing redline. The needle will start in the cold so I know the gauge is not buggered. The voltage is ok as the fuel is stable and correct.
Has been running hot , very but has not blown a gasket yet. I have replaced the shroud and changed the t-stat , the old one tested ok in the kitchen.
Any further thought?
PS the rad was replaced with new from our hosts.
Help....
The problem was not as bad at the winter romp but that was winter as well....

[Lalo88DK]

...

[cousindave]

Lordicon: my gfauge also started on cold and, when idling, sat at the "N" mark. Then when I drove it would climb to the red. Took out the stat and it did the same. Now, what made me scratch my head was that when I opened the rad to check the temp with a thermometer the rad was foamimg. I automatically went into "head gasket" mode. The forum suggested bad gauge, but I thought that was incorrect with foam in rad and gauge acting as it did. I decided to get a mechanical gauge and without stat it never goes higher then 140°. Now the foam ended up being a dirty radiator. Before tearing the engine down check with thermometer. It very well migjt be the gauge. Good luck!

[73series88]

at least you know all those parts you replaced are going to be in good standing for a while.
aaron

[Lord Icon]

I'm Confused....

Either I am going insane or there are two sensors near the t-stat housing. In the photo, the thermometer taped to the hose is just to the left and above it, the tab is facing up and sits in some plug approx 1 inch in diameter.
The other sensor is under the housing and it's tab faces the front of the rover. This is the one I have attached to the temp gauge.

Also at last fill up at the petrol station , I was still putting gas in the tank not diesel, so I am about 80% sure it's a 2.25 petrol engine.
I cannot find a wire in the loom that fits this sensor. All gauges work. I wonder if this goes to a OMG the engine is about to melt light. The former owner was in mid rebuild when I got this rig , and it is a combination of 4 trucks pieced together from the bone yard in Marlboro NH.
If I had the time I would yank all the wires out and start fresh, but that will have to wait for winter.
If only in the 50 or so years these truck were made someone had detailed the wiring harness locations and terminations for USA spec trucks. Ya know, like a company that sell parts for USA spec trucks... I know, I know, way too much to ask.
Do I seem bitter? Sorry . Must be from lack of blood form the bugs. We grow them big out here.
Somebody , anybody ....help...
Oh and sorry for the jacked thread, it just seemed to be a good ref for a overheating rover..
Bitter..... grumble,,,,,/... smack,,, splat,,,... itch....

[Lalo88DK]

.

[martindktm]

Lalo,

No, I am not sure. I measured the temperature by opening the radiator and using a meat thermometer in the coolant. I also measured the temperature when I tested the thermostat was opening.

I will try testing it again.

Rick

You cannot check temp like that...If the radiator cap is not sealed tight and the system is not pressurize it will not do is job of cooling...

[Lord Icon]

One down ..... many left

YES!!!! One more wire and sensor found and only 500 more black and green wires left... I was wondering if it was the cold start light..
On a side not, the temp when measured all over the engine is at 180. The returning coolant is at 140 -130 so it is cooling,,, guess the gauge or sensor is buggered...

[rickv100]

I picked up a digital thermometer on Friday and I was able to test the truck. With the thermometer taped to the hose, after 30 mins of idiling it never went above 150 degrees. The gauge was reading above the N mark.

I then pulled the instrument panel and took a multimeter to the terminals of the gauge.

With the engine running I have about 11.5 volts at the green wire but it does tend to jump around a bit. My truck appears to be a late Series 3 as it does not have a voltage stabiliser fitted. On the other terminal of the gauge I had 5 volts.

I am leaning to thinking it is a bad gauge. I am happy though that the truck is not overheating.

Rick

[crankin]

To tap into the discussion and to be able to go play around on the truck and check things...

What is the temperature that the 2.25 works best? 180?
What should the top and bottom tube temp be at idle?