P0128 code
 

2002 3.0 X5, 92k miles
I got this code
P0128 Range/Performance Problem In Thermostat

Everything is working as far a engine temp, cooling etc. What should I do or look for? Just did plugs, oil service, filters etc...

Thanks for your advice

thermostat or temp sending unit for computer (not guage) if you're guage is running in the middle I would say the thermostat is ok

thanks

hi all, i have the same issue. ses light on, checked and found code p0128. doesnt get hot, runs good, temp guage reads in the middle(pointing straight up at 12 oclock). so if its the t stat, i can change that out easily. if its the temp sending unit, does anybody know where its located and a part#, cost, etc. thanks, jspd234

Its the thermostat. The gauge on the dash is not accurate enough to show a thermostat that is opening early.

A code P0128 may mean that one or more of the following has happened:

Low engine coolant level
Leaking or stuck open thermostat
Faulty cooling fan (running too much)
Faulty coolant temperature (ECT) sensor
Faulty intake air temperature (IAT) sensor
use code scan tool clear the fault codes.

:iagree:

Replace engine thermostat, add antifreeze and bleed cooling system. You will be all set. IMO this is not a major code to lose sleep over. Good luck.

I am having the same issue. Temperature gauge seems normal and engine runs normal. I am curious how this original issue was addressed. X5 cooling system has multiple thermostat. Which one should I change?

one bolted to engine and sits between radiator hoses

http://www.autohausaz.com/secure/Par...1530139877.jpg

One sits below the expansion tank.

http://www.autohausaz.com/secure/Par...7111437362.jpg

dodoni1 listed a few probable causes, is there a good way to narrow down the faulty device?

A code P0128 may mean that one or more of the following has happened:

Low engine coolant level
Leaking or stuck open thermostat
Faulty cooling fan (running too much)
Faulty coolant temperature (ECT) sensor
Faulty intake air temperature (IAT) sensor

I have the same on my 2002 3.0 87k miles. I noticed that my antifreeze was running low but there is no leak. I refill the antifreeze and reset the code. After around 1K miles the code came back. Now I just need to find time to do the service maintenance on my cooling system (change out the thermo, water pump, pulley, 2 hoses, flush the radiator). I wonder how much time it takes to do the procedure??? Anybody wants to help, I supply the beer (j/k).

Ken, an entire cooling refresh including block drain should take 5 (working) hours with the right tools. If you are losing coolant you have a leak- either you can't see it or its evaporating off the block. Look for white/ gray crust on metal around and under cooling components. My 330i had a leak on the radiator end tank that took a complete refresh to finally track it down. Save time, do a refresh first, it ends up saving you money and time.

The thermostat in the first picture is the engine thermostat, the second is the automatic transmission thermostat I believe?