UPDATE question about temperature (engine)

[Paulpt]

I have been experiencing something strange with my x-5 and I wonder if anyone has any explanation or has experienced the same.

The temp indicator usually went up vertical (pointing at 12) after reaching normal temp. Winter (in NY), summer, AC on or off, etc. Always the same.

Today, the temp indicator stayed all the time within the two middle marks (pointing at 11 and 2), leaning always toward the coolest side. I do not think it may be calibration as, when stopped with the car at idle the temp indicator went back to vertical, going down again when moving.

Again, it has always been within normal operating temps, but I find it strange it seems to be working cooler. The ambient temp in NY is cooler but not less than 55 where I live.

In a few words is kind of the opposite of overheating. Car seems to be running normal otherwise

Any ideas what can this be?

x5 2001 3.0

Thanks in advance for your responses.

Paul

YES, IT WAS THE THERMOSTAT STICKING - GOT A COOLANT FLUSH AND REPLACEMENT TOO - ALL UNDER CPO - THANKS TO ALL WHO HELPED WITH SUGGESTIONS --- PAUL

[adrian.b]

Not sure what it is but do you hear the cooling fan running a lot more lately in the engine comp? maybe a sensor is going and keeping the fan on more?
You`d need to hook it up to a computer to read the errors or diagnostics.

[Paulpt]

Hi Adrian,

Not really, the fan seems to be running normally. I even tried with the AC on and off and no difference really. Very strange..I've heard about cars overheating but never underheating

[The Cleaner]

ANY deviation in that 12 o’clock strait up temp gauge position after it’s warm is telling you there is a problem. Here are a few things to check. The fact that the gauge is reading cooler makes me thing you have a thermostat that is not closing, but there are many things to look into.

-Expansion tank, look for cracks
- Check Radiator cap for leaks, if it’s original replace it, it’s probably not holding pressure any longer. Change your Oil cap at the same time, they need to hold pressure also.
- Check around the thermostat housing for any indication of leaking.
- check fan clutch for resistance, it should be firm but not jerky when you move it (engine off obviously).
- use a mirror to look under the water pump, that’s where leaks usually start.
-check the heater valves for leaking, they can suck air.
-check system for air at the bleeder

Look for any dry coolent it will be white chalky deposits

If you in the 100K range a water pump, thermostat and fan clutch are not out of the question to replace.

[Wagner]

Also of note:

You could be really lucky and your thermostat, instead of dying slowly and closing, is actually sticking in the open position. Cooling the engine too much instead of overheating it.

[Paulpt]

Thank you for your valuable responses.

Is it safe to drive it like this, I can't get to the dealer for another week and a half and I have to drive from NY to Maryland this weekend.

[onlybmw]

the cleaner and Wagner has it to a tee. check these and watch the dial during your trip. t-stat, may not be opening and closing correctly. check for leaks, especially when sitting car in MD, after your drive. It's safe to drive. Feel the hoses and look for any cracks in them. then to the mechanic and flush system and new t-stat, good time to check the water pump. hope this helps.

[Paulpt]

Does help a lot, thanks (this is the best site and the worst nightmare for dishonest dealers or mechanics)!

I've been checking for leaks, and did not see any, It may be the thermostast, though with 76,000 miles and a little over 20k for my CPO to expire I would not mind BMW replacing the water pump and hoses!