[BronxE60]

2004 525i m54engine.130k
I have checked the reserve tank and it isn't cracked, neither are the hoses coming from the radiator. Any ideas on what it could be?

 

[Jtbgonesailing]

Look down the left frame rail by heat controls valve. There are 3 or 4 heater hoses to the outside of intake manifold down low. If you are smelling the antifreeze inside the car, it may be the heater core giving out. Is the fluid level down in the expansion tank?

 

[BronxE60]

I only smell the antifreeze when I put my nose on the kidney grills. No smell inside the car

 

[Norskie]

You could have a leaking radiator. Pinhole from internal corrosion, or debris causing an external leak. You might see steam coming from the area once it gets hot. If you can see the radiator, an old motorcycle trick is to spray it with foot powder so any moisture becomes easier to see. Or remove it, take it to a radiator shop to pressure test and potentially repair.

 

[Jtbgonesailing]

Look for any white residue on all hoses, connections, fittings etc. you may have gotten lucky in that you smell the antifreeze in the engine space. If fluid level is down, there must be residue left somewhere. Now you just get in there and dig with a good light.

 

[BronxE60]

It's crazy because I've looked all over for steam when he car is hot and nothing. I will try looking for the residue. Another thing is that the fluid level is exactly where it's supposed to be according to the stick.

 

[Jtbgonesailing]

Did you confirm coolant level when system is stone cool?

 

[BronxE60]

Yes

 

[Jtbgonesailing]

Smell of antifreeze but no loss of coolant. Think it would just moniter it very closely.

 

[Kurt_]

Is it maybe possible it's your oil cooler gasket? does m54-have that? if it's gone oil and coolant can mix. Is your coolant coloured funny?

 

[Jtbgonesailing]

Kurt, unfortunately the M54's don't have a oil cooler.

 

[Cobrasa]

I would take the car to a radiator place and have the system pressure tested. BMW dealers can also do this, costly though.