[Nicky92]

I've been having this problem for about a year now. With no progress.

Here's the issue.

When my car is COMPLETELY cold, the second I unlock the car and the water pump starts going, and it stays on for about 10-15 mins.

It's just going on and on.

I replaced the water pump and thermostat thinking it was that, like an electrical issue. Nope. Same thing is happening

No MAX cool is not on, No codes. I have checked the wiring.

I don't know what else it could be?

Any ideas?

[Nicky92]

E90post says it's my fuel pump. Lol so done with that forum

[blown07]

Originally Posted by Nicky92

E90post says it's my fuel pump. Lol so done with that forum

I had a problem with my water pump running after the car was shut off if I used the RST (residual heat button). Probably not related but something that could not be explained by anyone.

[Nicky92]

Originally Posted by blown07

I had a problem with my water pump running after the car was shut off if I used the RST (residual heat button). Probably not related but something that could not be explained by anyone.

isn't that what it's supposed to do for the function

[Milan]

DME mosfets? What year is your car?

[Nicky92]

Originally Posted by Milan

DME mosfets? What year is your car?

I was thinking about that. It's a 2008

[Milan]

Originally Posted by Nicky92

I was thinking about that. It's a 2008

That would by my guess because you said the issue happens when it's cold.

[Nicky92]

Originally Posted by Milan

That would by my guess because you said the issue happens when it's cold.

You think I fried it?

Would there be any other symptoms?

[Nexic]

This happened to me, it was my water temp sensor on the oil filter housing. Seemed to be on the fritz but did not throw any particular codes. Once I swapped it out, the water pump stopped circulating constantly. My guess is that it sees something wrong with the sensor or temperature gradient and runs the pump at 100% to prevent a cooling failure. The gradient may still be within the tolerance of the DME and not throw a code, but thats just my guess.

[Nicky92]

Originally Posted by Nexic

This happened to me, it was my water temp sensor on the oil filter housing. Seemed to be on the fritz but did not throw any particular codes. Once I swapped it out, the water pump stopped circulating constantly. My guess is that it sees something wrong with the sensor or temperature gradient and runs the pump at 100% to prevent a cooling failure. The gradient may still be within the tolerance of the DME and not throw a code, but thats just my guess.

That's great I thought about that actually!

Def going to replace that

[Nicky92]

The sensor on the OFH is the oil pressure sensor btw.

The one under it on the cylinder head is the temp sensor

[Nicky92]

Welpp I changed it and it didn't work.

I am going to remove the Jb4 tomorrow and see if that helps, if not, I really don't know what else to do, looks like the only one with this on-going issue

[ibsr335]

It might be the IBS (negative battery cable) unplug the wire with the blue connector off the neg battery cable and see if it stops.

[Nicky92]

Originally Posted by ibsr335

It might be the IBS (negative battery cable) unplug the wire with the blue connector off the neg battery cable and see if it stops.

I heard something like this. I will give that a shot later. Thank you

[Nicky92]

I unplugged it, still running.

Might have to reset adaptations. But I am going to remove the jb4 tonight, i have a strong feeling it's something with that.

[Nexic]

Originally Posted by Nicky92

Welpp I changed it and it didn't work.

I am going to remove the Jb4 tomorrow and see if that helps, if not, I really don't know what else to do, looks like the only one with this on-going issue

Did you check the plug going into the thermostat? Make sure it is plugged in correctly and all the way in.

[User Name]

I typically hate the type of post I'm making here, but throwing it out there in case someone is going through what I did.

I had an issue where a bad alternator voltage regulator was causing waterpump, IBS and oil level sensor issues. Codes, low voltage mode, all sorts of issues. The moment I disconnected the data cable going to the alternator the problems cleared.