running hot

[Harrini1]

Hi All

My series 5 is running hot I have flushed cooling system and I've checked the thermostat which seems to work fine - is it a good chance that the water pump has failed? Or should I be checking anything else before I have to buy a new water pump?

Thanks



Nick

 

[hdar5702]

Are you losing coolant? How hot is too hot? Is the temp gauge indicating the coolant is too hot? If so have you verified the accuracy of the gauge?
The radiator cap could be faulty(not allowing the cooling system to pressurize).
If the radiator is good(no blockage), thermostat is working, the fan belt tensioned(fan is turning), correct radiator cap w/ a good seal and the coolant is too hot...
sorry but it could be the head gasket.

 

[Knightowl61]

Check the temperature with a laser thermometer to verify temperatures and find any hot spots.
Usually cylinder #4 water way gets a lot of crud blocking water to the cylinder walls.

 

[husky drvr]

Hi All

My series 5 is running hot I have flushed cooling system and I've checked the thermostat which seems to work fine - is it a good chance that the water pump has failed? Or should I be checking anything else before I have to buy a new water pump?

Nick,

If possible, please list the conditions of when and what is the engine and car doing when running hot.

If it's just the gauge indicating a high temp AND the engine still continues to seem to be running normally, then you should check to see if the "voltage stabilizer" is providing the fuel and temp gauges with ~10 volts. The stabilizer grounds through the case mounting so ensure the screw is tight. If the stabilizer has failed with the contacts closed, then the gauge supply voltage will be full battery voltage and cause the fuel and water temp gauges to read correspondingly high. You should find the stabilizer mounted on a dash brace above the steering column.

The video explains the problem and cure concerning the grunge in the back of the block.

Hope this helps,

 

[Harrini1]

so if I told you that the fuel gauge goes over to full (when i know that the tanks not full) - point to the voltage stabilizer?
no leaks, cap fits and fan turns.

nick

 

[hartmandm]

so if I told you that the fuel gauge goes over to full (when i know that the tanks not full) - point to the voltage stabilizer?
no leaks, cap fits and fan turns.

nick

Not necessarily. Measure the resistance being provided by the fuel sender at the fuel gauge first.

Check the actual engine / coolant temperatures using an infrared thermometer.

More details about temp and fuel gauges is at http://mhartman.net/files/sunbeam/fuel & temp gauges.pdf

 

[alpine_64]

so if I told you that the fuel gauge goes over to full (when i know that the tanks not full) - point to the voltage stabilizer?
no leaks, cap fits and fan turns.

nick

Nick... Is the car loosing coolant?
Have you verified what the actual temperature is using an infrared thermometer....
These are steps 1 and 2

 

[ForzaDesign]

I read somewhere that the replacement temp sending units are not accurate. The impedance needs to match the gauge.
I just got the 67 back on the road. I had Foreign Speedo in San Diego check and calibrate all the gauges. When car is at temp the gauge is at approx 110°C. Not correct obviously.
So, I laser checked the thermostat housing, radiator tank and fins. Turns out gauge wasn't even close.
This indicates the impedance of the temp sender is not correct for the gauge.
I used a 100ohm pot to adjust the impedance to match the gauge. This turned out to be approx 20ohms.
gauge now matches the actual thermostat housing temp with a delta for thermal conductivity loss.
Final installation will be to make a 20ohm .5W radial metal film resistor with .25" quick connects soldered to the leads. This will mount directly to the back of the temp gauge.

 

[Scotty]

Hi All

My series 5 is running hot I have flushed cooling system and I've checked the thermostat which seems to work fine - is it a good chance that the water pump has failed? Or should I be checking anything else before I have to buy a new water pump?

Thanks



Nick

For the water pump, check the weep hole under it to see if it's dripping out. Otherwise, take the V belt off, and, minding the mechanical fan blades, if you have them installed, spin it. There should be a little resistance but it should spin smoothly without any roughness, grinding or wobbling. If those things aren't present and you don't have an odd greasy-looking stain on the inside of your bonnet , the Water Pump is probably fine.

Beyond that, like Johnny Five says in Short Circuit, we need more data. What else is going on that has you considering its getting too hot or is it just the gauge? If its the gauge, when I had stock gauges, my problem was the voltage stabilizer wasn't grounded so maybe check that.

Hope something here helps you.