Temp Gauge Straight Up?

[JMI]

The status of the cooling system is as follows:

Coolant level is normal
System is bled of air
I replaced the thermostat about 2 months ago (engine was running cold on highway)
Main fan/clutch works
Auxiliary fan works (it runs with AC on - not certain if it runs at high water temp)
According to the previous owner's service records a new water pump was installed 46k miles ago and 31k miles ago a new radiator, upper radiator hose and coolant sensor were installed.
Radiator looks clean on the outside

The water pump is "relatively" new but from the horror stories posted on the board it may be worthwhile to change it out. Will order it soon. Any suggestions on a brand? Are plastic impeller failures still an issue?

TIA

Jim

[bmwrp8]

The status of the cooling system is as follows:

Coolant level is normal
System is bled of air
I replaced the thermostat about 2 months ago (engine was running cold on highway)
Main fan/clutch works
Auxiliary fan works (it runs with AC on - not certain if it runs at high water temp)
According to the previous owner's service records a new water pump was installed 46k miles ago and 31k miles ago a new radiator, upper radiator hose and coolant sensor were installed.
Radiator looks clean on the outside

The water pump is "relatively" new but from the horror stories posted on the board it may be worthwhile to change it out. Will order it soon. Any suggestions on a brand? Are plastic impeller failures still an issue?

TIA

Jim

check your aux.fan if it works in high mode...might be its low all the time

[JMI]

Want to close out the thread with the final resolution.
I should have known better then to assume (in this particular experience) new parts, out of the box are good. In the past, although infrequently, have found faulty new parts. Why I chose to overlooked what was staring me in the face I don’t know.
I had replaced the thermostat (with a lower temp one), water pump, fan clutch, auxiliary fan switch, coolant temperature sensor that goes to dash board, expansion tank and cap. Basically almost everything except the radiator, aux fan and hoses were replaced. Still the temperature would creep up at idle between ½ and ¾ on the gauge.
Summer turned to fall and the daytime temperature began to cool and with it my concern about the overheating problem went on the back burner, but it never completely left my mind as I would drive along.
In the last week or so I decided to revisit the issue well in advance of Spring and warming temperatures.
Bottom line: the problem with my M30’s cooling system was a bad viscous fan clutch.
After reviewing a lot of old posts and “googling” around the web I came to the conclusion that it could only be the fan clutch. I had read in numerous posts that a slowly rising temp at idle indicated a bad clutch. Also I overlooked the fact that I could stop the fan from spinning regardless if the engine was cold or hot. For that matter after stopping the fan I could spin it backwards with the engine running. I just assumed the Behr clutch that came new from BMA Auto Parts had to be good.
Called BMA with the expectation of having to shell out for the price of a new clutch but was pleased to learn that the part came with a one year warranty and they would ship me a replacement the same day (I received a Sachs clutch in a couple of days).
So now it looks like I will have to put the 80 degree Celsius stat back in because the temperature gauge is now spending most of its time below the straight up middle mark.

One thing to note: When replacing the Behr with the Sachs I examined the bi-metal strip that operates the plunger/valve stem/whatever it is called, with the non-working Behr. The strip was flat and the stem pressed in, whereas with the working Sachs the strip was bowed and the stem extended outward. Both were at “room” temperature.

What a relief to get this problem fixed.


Jim

[philbyil]

that the temperature needle is no lower than around 11 o'clock.
Mine ran just like that (below the mid-mark) for years before I changed the water-pump, thermostat (same temp) and thermo cover. After I replaced all of the above, it now runs exactly mid-mark and steady.

Want to close out the thread with the final resolution.
I should have known better then to assume (in this particular experience) new parts, out of the box are good. In the past, although infrequently, have found faulty new parts. Why I chose to overlooked what was staring me in the face I don’t know.
I had replaced the thermostat (with a lower temp one), water pump, fan clutch, auxiliary fan switch, coolant temperature sensor that goes to dash board, expansion tank and cap. Basically almost everything except the radiator, aux fan and hoses were replaced. Still the temperature would creep up at idle between ½ and ¾ on the gauge.
Summer turned to fall and the daytime temperature began to cool and with it my concern about the overheating problem went on the back burner, but it never completely left my mind as I would drive along.
In the last week or so I decided to revisit the issue well in advance of Spring and warming temperatures.
Bottom line: the problem with my M30’s cooling system was a bad viscous fan clutch.
After reviewing a lot of old posts and “googling” around the web I came to the conclusion that it could only be the fan clutch. I had read in numerous posts that a slowly rising temp at idle indicated a bad clutch. Also I overlooked the fact that I could stop the fan from spinning regardless if the engine was cold or hot. For that matter after stopping the fan I could spin it backwards with the engine running. I just assumed the Behr clutch that came new from BMA Auto Parts had to be good.
Called BMA with the expectation of having to shell out for the price of a new clutch but was pleased to learn that the part came with a one year warranty and they would ship me a replacement the same day (I received a Sachs clutch in a couple of days).
So now it looks like I will have to put the 80 degree Celsius stat back in because the temperature gauge is now spending most of its time below the straight up middle mark.

One thing to note: When replacing the Behr with the Sachs I examined the bi-metal strip that operates the plunger/valve stem/whatever it is called, with the non-working Behr. The strip was flat and the stem pressed in, whereas with the working Sachs the strip was bowed and the stem extended outward. Both were at “room” temperature.

What a relief to get this problem fixed.


Jim

[Ross]

Thanks for the follow up.