[DiamondPurity]

Has anyone had this issue? I just got a 2008 328i and now a blue liquid is appearing by the gas pedal. I’ve tried lots of searches but can’t find out what it could be, assuming coolant hose leak or wiper fluid housing maybe. Anyone know what’s under or to the right of the door well?

[TheMidnightNarwhal]

Usually coolant inside the cabin would come from the HVAC, specifically heater core or heater core hoses unfortunately.

[Hoody007]

Good way to tell if it’s washer fluid or coolant would be to feel the fluid. If it’s oily, it’s coolant, if it’s not, then washer fluid.

Hopefully it’s washer fluid - is your windshield original / is the cowl in good shape?

[eljay]

Agreed with above.
To eliminate washer fluid, open the hood, remove the cabin filter housing cover (6 screws). Then have someone operate the windshield washer and observe from engine bay at the cabin filter opening if any fluid leaks under the windshield cowl. If it leaks through there, you should be able to spot dried or fresh fluid in that area or near the washer fluid hoses.

If it's simply leaking from the top of the windshield into the cabin due to bad cowl seal, then you would have wet carpet there anytime it rains.

But if the carpet feels oily as mentioned above, then it may be coolant. If it leaked that much, you would notice a drop in level, so check that first at the reservoir.

[oVeRdOsE.]

get a black interior . / problem fixed

[mrjimyjohn]

Could this just be dye from new shoes or jeans?

[TGTIW]

The heater core piping runs right above the accel pedal.

[mainbearing]

+1 blue BMW coolant. Windshield fluid should not flow inside the cabin.

[clegg]

Agree on the coolant leak from heater core. Does the interior have an unusual odor?

[Mike K]

If it's the heater core it's a cheap part but a big job:

[rbryantaz]

My E70 did run the washer line through the inside of the car and it froze up and split. It took forever to figure out how washer fluid was leaking out of the floorboard drains... In my case the fluid would leak out pretty quickly.

The smell of coolant vs washer fluid is also very different (They also taste different with the poison coolant being sickly sweet but don't try that at home.. It is poison so definitely don't swallow it...)

-Rich

[StradaRedlands]

Man, hope it is just washer fluid... if coolant... yikes!

[TGTIW]

The heater core can be replaced without removing the dash. It possible with just removing the steering column, or you can be super-janky and just bend the inlet and outlet pipe like the dealer that replaced mine did.

[Efthreeoh]

Originally Posted by StradaRedlands

Man, hope it is just washer fluid... if coolant... yikes!

Reminds me of an incident from the mid 1990s. My wife and I were sitting in the traffic jam that was routine for trying to get into Fed Ex Field (Jack Kent Cook Stadium then) back in the day. A few cars ahead of us was a mid '80s E28 5'er. Zero traffic movement. All of a sudden all 4 doors of the 5'er simultaneously pop open and the occupants spill out out of the car. The heater core blew like a volcano. The windows instantly fogged over and the sweet smell of BMW coolant greeted us bystanders, most all of who didn't realize what had just happened.

Hilarious.

[mecheng77]

The windshield washer fluid runs in the wheel well, I don’t think it runs inside the car at all

[StradaRedlands]

Originally Posted by Efthreeoh

Reminds me of an incident from the mid 1990s. My wife and I were sitting in the traffic jam that was routine for trying to get into Fed Ex Field (Jack Kent Cook Stadium then) back in the day. A few cars ahead of us was a mid '80s E28 5'er. Zero traffic movement. All of a sudden all 4 doors of the 5'er simultaneously pop open and the occupants spill out out of the car. The heater core blew like a volcano. The windows instantly fogged over and the sweet smell of BMW coolant greeted us bystanders, most all of who didn't realize what had just happened.

Hilarious.

I had a '73 MGB that leaked coolant whenever I turned on the heater and opened the valve.
That was fun for a minute...

[2one3E90]

Originally Posted by Efthreeoh

Reminds me of an incident from the mid 1990s. My wife and I were sitting in the traffic jam that was routine for trying to get into Fed Ex Field (Jack Kent Cook Stadium then) back in the day. A few cars ahead of us was a mid '80s E28 5'er. Zero traffic movement. All of a sudden all 4 doors of the 5'er simultaneously pop open and the occupants spill out out of the car. The heater core blew like a volcano. The windows instantly fogged over and the sweet smell of BMW coolant greeted us bystanders, most all of who didn't realize what had just happened.

Hilarious.

Have you ever changed your heater core? And how often do you use your heater in your 500,000 miles e90?

[Efthreeoh]

Originally Posted by 2one3E90

Have you ever changed your heater core? And how often do you use your heater in your 500,000 miles e90?

Not answering that. Fear of jinxing myself. I did change the heater core in my E30. It took just 45 minutes.

[e90yyc]

Could be blinker fluid

[Serf27]

Every forum member has commented on here, except the OP.

[StradaRedlands]

Originally Posted by Serf27

Every forum member has commented on here, except the OP.

We're all cringing vicariously, waiting to hear the results!