X5 - Strong Smell Inside the Cabin

[CLS70]

X5-2007-3.0si-160K KM

Have a recurrent issue; every couple of days I get a strong smell from the vents, it is a bit of burning smell (it does not smell like oil, not electrical either). The smell is specially pronounced after breaking hard or when starting the car just after a long drive.

I believe is a Coolant Leak as I had to top up the tank significantly, there are no signs on the floor and when I have opened the hood to check for a 'smoking' source have been unable to see anything.

Any suggestions on what to look for / where to check?

Thanks

[AlpineX]

Originally Posted by CLS70

X5-2007-3.0si-160K KM

Have a recurrent issue; every couple of days I get a strong smell from the vents, it is a bit of burning smell (it does not smell like oil, not electrical either). The smell is specially pronounced after breaking hard or when starting the car just after a long drive.

I believe is a Coolant Leak as I had to top up the tank significantly, there are no signs on the floor and when I have opened the hood to check for a 'smoking' source have been unable to see anything.

Any suggestions on what to look for / where to check?

Thanks

Coolant has a distinct sweet smell, the vents can bring in smell from inside the engine bay fresh air vent or from within the heater box assembly that houses the heater core. If you are smelling through the vents, you are dealing with an external leak.

I am guessing you have a small leak from a hose or clamp somewhere, flexes on hard braking and leaks when sitting under pressure... look for wetness, dried residue, or steam.

[Skyline]

Chances are, if it's some sort of fluid vapor from the engine compartment, it's entering through the cabin air filters. Pull the covers off those and see if there's any fluid there. Figure out what it is, and trace the source. If it's not coming from there, I'd be worried about burning electronics behind the dash somewhere.

I had an oil leak on the front of my engine, and oil made it all the way up inside the fender to where the cabin air filter was on the passenger side. In fact, some oil even got sucked into the vent of the windshield washer bottle, and washing the windshield caused a horrible mess. In that case, there wasn't oil sucked through the filter, but the general area was an oily mess. Had I not addressed the problem, I'm sure oil into the interior vents would have happened. Major cleanup was required.

On another occasion, when I had a power steering line burst, (down at the bottom of the radiator), I had a cloud of vaporized power steering fluid come through the vent system. This happened within seconds of the steering line bursting. Needless to say, in that case, there was fluid absolutely everywhere in the engine bay.

[CLS70]

Thx - will check those two - I have been looking at the posts and have found references to Expansion Tank leaks, however, that seems to be on the opposite side (I think coolant may be spilling on the exhaust manifold)

[AlpineX]

Taking the engine acoustic cover off should open up the engine bay somewhat for viewing if needed. Look at every coolant hose, trace them back from the reservoir.
Real oem has some nice diagrams as should newtis.info.