Issues with waterpump and/or cooling

[Snowman]

The thermostat has a big say and the DME too ...

So a faulty thermostat could cause the wp to turn off?
How?
How do i test the DME and also thermostat if they both can cause the wp to turn off.

If i connect INPA to the car and send the command to the wp to run 50% it does not run at all once the issues start.
However if i do it on a good day, which the wp decides to work, then it will run at the commanded rate..
In my book that would be an indication of that the DME works and also thermostat..
But if someone can correct me im more than happy since this is starting to get exhausting...

 

[tony@codewerx]

Okay this is What happened to me. After hard acceleration the cable in the trunk( which powers the water pump) that connects to the battery. Came loose causing intermittent failures.It finally blew the fuse one day( on top of the battery) not the fuse in the engine bay. Maybe check your cable

Doubt that cable from the battery powers the water pump.

It does share the same bus line as the other bsd devices like the alternator and the water pump.

So a faulty thermostat could cause the wp to turn off?
How?
How do i test the DME and also thermostat if they both can cause the wp to turn off.

If i connect INPA to the car and send the command to the wp to run 50% it does not run at all once the issues start.
However if i do it on a good day, which the wp decides to work, then it will run at the commanded rate..
In my book that would be an indication of that the DME works and also thermostat..
But if someone can correct me im more than happy since this is starting to get exhausting...

Disconnecting the thermostat should keep the pump running. Don’t think the Dme would be the problem.

You still getting bsd codes about the pump ?

 

[Snowman]

Doubt that cable from the battery powers the water pump.

It does share the same bus line as the other bsd devices like the alternator and the water pump.



Disconnecting the thermostat should keep the pump running. Don’t think the Dme would be the problem.

You still getting bsd codes about the pump ?

Nope when i replaced the thermostat all BSD codes went away.
The only codes i get now would be 2e81 and 2e82.
Today i also replaced the battery and pulled the JB4.
I still get 2e81 and 2e82 and temperatures that skyrocket..

 

[tony@codewerx]

Nope when i replaced the thermostat all BSD codes went away.
The only codes i get now would be 2e81 and 2e82.
Today i also replaced the battery and pulled the JB4.
I still get 2e81 and 2e82 and temperatures that skyrocket..

Get your pump into bleeding mode. You don’t have to start the engine for that.

Open the expansion tank cap and look at how it’s pissing in there.

Those codes points to a pump that is working but slow impeller speed ...

 

[Snowman]

Get your pump into bleeding mode. You don’t have to start the engine for that.

Open the expansion tank cap and look at how it’s pissing in there.

Those codes points to a pump that is working but slow impeller speed ...

Then what?
I have verified that the pump actually runs when bleeding.
I have also verified with INPA and by simply checking temperatures that the pump seems to work sometimes.
When it works i dont have any codes.
Then out of nowhere it stops pumping coolant, temperatures skyrocket and i get the 2e81 and 2e82 codes.

Also you are incorrect, 2e82 is a complete shutoff, not just that it runs slowly.

 

[tony@codewerx]

Then what?
I have verified that the pump actually runs when bleeding.
I have also verified with INPA and by simply checking temperatures that the pump seems to work sometimes.
When it works i dont have any codes.
Then out of nowhere it stops pumping coolant, temperatures skyrocket and i get the 2e81 and 2e82 codes.

Also you are incorrect, 2e82 is a complete shutoff, not just that it runs slowly.

You did mention 28e1 as well. And obviously if it slows to a crawl the next code would be 28e2. You would want to hunt for the issues around 28e1.

As I said before - look at how it’s pissing in the tank not look at if it pisses in the tank. It’s different.

Go compare with the way it looks with a ride with a healthy pump.

Maybe it’s time to face reality. Remove the pump and turn it by hand to see if it’s hard.

 

[Snowman]

You did mention 28e1 as well. And obviously if it slows to a crawl the next code would be 28e2. You would want to hunt for the issues around 28e1.

As I said before - look at how it’s pissing in the tank not look at if it pisses in the tank. It’s different.

Go compare with the way it looks with a ride with a healthy pump.

Maybe it’s time to face reality. Remove the pump and turn it by hand to see if it’s hard.

Yes they both come together, ive never had just 2e81.

Yes im aware of this, but the thing is that when you run the INPA bleeding it will report the actual speed of the wp in % and also the commanded speed. I have verified it through INPA that the wp indeed runs at the correct speed, that the dme requests.

The interesting thing is why it is intermittent..
I'm aware that the next step would be to remove it, but i have no hopes on finding a wp that is tough to move, since it sometimes runs just fine, without codes or skyrocketing temperatures..

 

[pdxbimmertech]

If I were diagnosing this I would pay very close attention to the wiring to the thermostat that you said had some damage. I have seen an N52 powered X-drive model with broken passenger side engine mount bracket bolts which caused the engine to drop down just enough to pinch the t-stat wiring causing a short to ground and messing up all kinds of stuff including getting BSD faults. If the wiring looks like it was impacted/smashed I would repair it there and possibly ohm it out from the t-stat up to the DME to be 100% certain you aren't chasing a harness issue. If it's losing connection or shorting out it could be an intermittent issue like you are describing.

 

[Snowman]

If I were diagnosing this I would pay very close attention to the wiring to the thermostat that you said had some damage. I have seen an N52 powered X-drive model with broken passenger side engine mount bracket bolts which caused the engine to drop down just enough to pinch the t-stat wiring causing a short to ground and messing up all kinds of stuff including getting BSD faults. If the wiring looks like it was impacted/smashed I would repair it there and possibly ohm it out from the t-stat up to the DME to be 100% certain you aren't chasing a harness issue. If it's losing connection or shorting out it could be an intermittent issue like you are describing.

Most likely i did the damage to the lead to the thermostat when i removed it the first time. I had a hard time removing the thermostat since the guide i used for the wp replacement mentioned to pull the thermostat out towards the radiator.
When i did this i most likely pushed the lead from the thermostat onto a sharp edge of the subframe and peeled away some of the insulation.
None of the copper wires that forms the lead have been damaged and what i did now to fix it was simply putting a new shrink sleeve that was prefilled with something similar to glue, so when you heat it i can basicly press on it with my fingers and seal the whole thing of.

Yesterday i also removed the fan to make more room to try and find any damage to any wires to the wp or thermostat, without finding anything..

Although how would a fault thermostat cause 2e81 and 2e82 codes? Even if the thermostat would be broken/open/closed, there would still be flow from the wp?
What i have done now, to be 100% of the flow of the wp is simply connecting INPA to the car once i see temperatures skyrocket.
When i have inpa connected i can very the speed of the pump and once temperatures skyrocket the pump is dead, it shows 0%.
It does not matter if i then clear the codes, the fault is still there and pump speed is 0 until i leave the car for the night and come back in the morning. In the morning the WP seems to be working again, most likely due to the fact that everything has cooled down.

 

[NoQuarter]

So you are saying the pump works well until it gets hot?

 

[Snowman]

So you are saying the pump works well until it gets hot?

Not always, but yes.
Today I let it idle for a short while, no problem.
Then I went for a short drive and it stopped right away.
Yesterday I drove for 20minutes until I started pushing the car for about 5-10min and then the wp stopped working at temperatures started to increase rapidly. .

And yes, I've been constantly been monitoring temperatures every time I've driven the car.

 

[Rcboosted2007]

Doubt that cable from the battery powers the water pump.

It does share the same bus line as the other bsd devices like the alternator and the water pump.



Disconnecting the thermostat should keep the pump running. Don’t think the Dme would be the problem.

You still getting bsd codes about the pump ?

It does in fact provide power for my pump 2007 e90, why would i make up such a thing? Pull the cable from the power distribution box.then check power to fuse in dme. Large 50 amp.0vdc.plus you will get the codes OP is showing. When you open the distribution box, you will find non replaceable fuses. Check to make sure this is tight. The hard acceleration caused my battery to slide and made this connection fail randomly. TONY.Its great to add more suggestions, however it is counterproductive to kill useful leads.

 

[Rcboosted2007]

Thermostat is a fail safe configuration. Open

 

[Rcboosted2007]

If I were diagnosing this I would pay very close attention to the wiring to the thermostat that you said had some damage. I have seen an N52 powered X-drive model with broken passenger side engine mount bracket bolts which caused the engine to drop down just enough to pinch the t-stat wiring causing a short to ground and messing up all kinds of stuff including getting BSD faults. If the wiring looks like it was impacted/smashed I would repair it there and possibly ohm it out from the t-stat up to the DME to be 100% certain you aren't chasing a harness issue. If it's losing connection or shorting out it could be an intermittent issue like you are describing.

This would be a great next step

 

[Rcboosted2007]

Here you go. Hope you catch the issue and the pump was not a faulty unit.

 

[NoQuarter]

I'm gonna go with replace the pump.

The DME is expecting it to be on. The DME says it is not running. You know it is not running after it heats up.

This is the same failure we see when it fails permanently. You just happen to have something more borderline that is sensitive to heat in the control board.

This is my prediction but certainly you need to satisfy any concern with the harness. Get a test lead on the power connection and see if it still has power when it is has stopped working.

 

[Snowman]

View attachment 14147
Here you go. Hope you catch the issue and the pump was not a faulty unit.

Could you please explain between which points i should measure?
I do realize that what you posted is a schamtic for the car, however im not used to reading full schematics like that one, so i'm having a hard time reading it since i dont know the name of the connectors etc.

 

[Snowman]

I'm gonna go with replace the pump.

The DME is expecting it to be on. The DME says it is not running. You know it is not running after it heats up.

This is the same failure we see when it fails permanently. You just happen to have something more borderline that is sensitive to heat in the control board.

This is my prediction but certainly you need to satisfy any concern with the harness. Get a test lead on the power connection and see if it still has power when it is has stopped working.

Do you have any suggestions on how to check this?
I assume getting the car to a ramp, while the car is running and simply pulling the wp-connector and simply measuring into it, isnt really an option
However im 95% sure that there is power.
Because yesterday i hooked up INPA once the wp was not working, i sent the command to the WP for 5% speed and for 1second i had 5% speed of the wp, which lowered the water temperature by ALOT, after that second of operation it turned off again. I then tried 5% again and 50% without any reaction..

 

[Snowman]

Also im fairly sure that when i measured the voltage to the WP connector i had 12v at pin 1 and 3, while pin 2 had 7,5v.
According to what ive read i should have 12v and pin 1, 2 and 7,5v on pin 3. How this could have gotten mixed up i cant really explain.. But i will double check this tomorrow..

 

[Snowman]

Could someone confirm that the pinout in this guide is incorrect for the N54 waterpump?
https://www.e90post.com/forums/showpost.php?p=11873337&postcount=17
In the guide it says:
"NOTE: All measurements should be performed with the battery charger connected to the vehicle. 1. Measure the following at connector X6035 on the electric coolant water pump: - E90 and E91 - Pin 1 (fuse F09) and Pin 4 ground (X6455) = 12 volts
- E60 and E61 - Pin 1 (fuse F23 and Pin 4 ground (X6455) = 12 volts
- Pin 2 (fuse F02) and Pin 4 ground (X6455) = 12 volts
- Pin 3 BSD signal (DME Pin 26) and Pin 4 ground (X6455) = 7.5 - 8.5 volts - If any of the above measurements are incorrect, continue troubleshooting using the DIS Plus or GT1 to determine the source of the problem.
- If all of the above measurements are correct, proceed to step 2. "

However the guide is for N52 and i belive it has the wrong pinout for N54..
Because i have 12v on pin 1 and 3, while pin 2 has 7,5v..