BMW E46 Fanatics Forum banner

1 - 20 of 25 Posts

·
Registered
Joined
·
104 Posts
Discussion Starter #1
How many miles did your original E46 M3 waterpump and or thermostat last? If still on the original, how many miles are you at now? Just curious.
 

·
Registered
Joined
·
325 Posts
How many miles did your original E46 M3 waterpump and or thermostat last? If still on the original, how many miles are you at now? Just curious.
113K. 2003 M3 cab. OTOH fan clutch failed and I did SERP belts, radiator, hoses, and expansion tank. The M3 water pump and thermostat are pretty reliable unless a bearing fails.
 

·
Registered
2003 325iT
Joined
·
1 Posts
140k, but I did not wait for it to explode. Replaced it with the metal impeller one from Bimmerworld (and thermostat at the same time). On a sadder note, the power steering pump failed, but I guess it's an opportunity to upgrade to the LF-30 power steering pump.
 

·
Registered
Joined
·
999 Posts
My thermostat failed ~116K miles. IIRC it was stuck open. I did a cooling system overhaul at ~130K and replaced the water pump at that time. I believe it was the original pump. IIRC the weep hole was crusted over with dried coolant and I think I caught it before it would have failed. I have a 2001 325ci 5 speed manual.
 

·
Registered
E30M3 Race F10 535 R1150Rt M Coupe
Joined
·
4,163 Posts
The S54 water pump is one of BMW's better designs. They are the least frequently replaced pump here.
One of the things most miss is that when replacing the thermostat, one needs to replace the thermostat housing. There is a rubber sealing ring inside (used to be able to replace the seal itself on older cars) but not on the S54.
The rubber seal wears out and when the thermostat is closed, sometimes too much coolant passes around the outer perimeter. leading to intermittent thermostat plausibility codes:

The thermostat gets blamed, but in reality it's fine. There's just a little too much coolant getting around the outside and at the same time some cold coolant getting in from the other side.
The engine (again intermittent) whilst monitoring coolant temperature can interpret such as a failing thermostat.
We use only genuine pumps/housings.
 

·
Registered
Joined
·
221 Posts
at 143k, still working well, but I replaced all the cooling components just in case, it is 17 years old.
 

·
Registered
Joined
·
166 Posts
Pump seized up and lost all coolant around 150k miles. Did a full refresh and swapped to Mishimoto fan after.
 

·
Registered
Joined
·
86 Posts
The S54 water pump is one of BMW's better designs. They are the least frequently replaced pump here.
One of the things most miss is that when replacing the thermostat, one needs to replace the thermostat housing. There is a rubber sealing ring inside (used to be able to replace the seal itself on older cars) but not on the S54.
The rubber seal wears out and when the thermostat is closed, sometimes too much coolant passes around the outer perimeter. leading to intermittent thermostat plausibility codes:

The thermostat gets blamed, but in reality it's fine. There's just a little too much coolant getting around the outside and at the same time some cold coolant getting in from the other side.
The engine (again intermittent) whilst monitoring coolant temperature can interpret such as a failing thermostat.
We use only genuine pumps/housings.
Could such a thing cause a P0128 coolant thermostat below thermostat regulating temperature?
 

·
Registered
Joined
·
221 Posts
could be just the temp sensor, but if it is the thermostat just change it, fairly easy
 

·
Registered
E30M3 Race F10 535 R1150Rt M Coupe
Joined
·
4,163 Posts
Could such a thing cause a P0128 coolant thermostat below thermostat regulating temperature?
Yes, if you're referring to the thermostat housing/integrated seal. Also the code usually starts sporadically, becoming more frequent as the seal wears/lets more coolant bypass the closed thermostat.
It's tantamount to having a thermostat that just won't close that last little bit.
 

·
OEM ///PLUS
2003 M3 6MT Slicktop
Joined
·
23,823 Posts
Water pump was original at 188,000 when it died on me. The plastic hose from expansion tank to top of radiator 195,000.
I suggest replacing both prior to these miles. And do thermostat same time.
 

·
Registered
2003 BMW M3
Joined
·
84 Posts
How many miles did your original E46 M3 waterpump and or thermostat last? If still on the original, how many miles are you at now? Just curious.
Lasted 159k miles. Bearing blew and it was a disaster. Just changed the entire cooling system recently.
 

·
Registered
Joined
·
4,590 Posts
Lasted 159k miles. Bearing blew and it was a disaster. Just changed the entire cooling system recently.
Whenever the main belt is removed I always make a habit of checking all pulley bearings (spin them and listen to the dried grease rattling of the rolling balls) and wiggle the pump shaft radially and axially (if there is any insignificant plays then time to replace it). If the pump shaft seal starts to develop a small leak the coolant got in the bearings and damaged them, causing the plays. Otherwise keep driving on.
 

·
OEM ///PLUS
2003 M3 6MT Slicktop
Joined
·
23,823 Posts
not sure if all posters are aware but OP question is in regards to the M3. which has a much more robust water pump design/build than the non-Ms. Genuine BMW M3 pump is not available sold as OEM outside of BMW (also much more expensive). Only sold to BMW.
 

·
Registered
Joined
·
86 Posts
I'm at 118k miles and have the p1028 error code. Thinking of purchasing the ECS cooling kit 1, with new hoses, water pump, thermostat, etc. ($375 I think it was). OR just replace the thermostat. I put about 3 to 4k miles a year on the car. Looking for opinions if I should go all in and do it all, or just change out thermostat? Don't want to throw money at it needlessly. Thoughts please...
 

·
OEM ///PLUS
2003 M3 6MT Slicktop
Joined
·
23,823 Posts
118k and you only put 3k-4K a year.
No brainer, just do the t-stat and change the coolant to new genuine BMW. maybe change the green o-ring on the temp sensor on the lower radiator hose.
 
1 - 20 of 25 Posts
Top