I love the smell of anti-freeze in the morning!

[granit_silber]

Hey Everyone,

I'm pretty sure I know the answer to this, but wanted to check and be sure begin I start pulling stuff apart.

I flushed my cooling system in late Spring and refilled according to spec. About 6 weeks ago I get a low coolant warning (1st time that's ever happened), so I refilled the expansion tank.

Now when I turn on the heat I get the coolant smell, but only for the first 5 -10 of operation then the air smells okay.

My heater core's going, right?

-ashley

[Alpinewhite]

Make sure all the hoses are connected properly in the expansion tank. Make sure the coolant sensor is connected tight. If there is a problem there you will get coolant smell because the inlet vents are some where close to the expansion tank.

I had little coolant smell and I suspected the same. Finally it happened to be that the coolant sensor was loose (I didnt connect it properly).

EDIT: Just saw that yours is 525. Do 525s have Expansion tank in the fire wall? If not ignore my post.

Arun

[Dave M]

Thats my guess, but I've yet to run across this in my e34 (only vw's). Ryan R and others will certainly have something to sayn (as long as we keep it bumPed).

Dave M

[Dave M]

If there is a problem there you will get coolant smell because the inlet vents are some where close to the expansion tank.

Arun

I don't believe an M50 set-up (expansion tank atached to rad) will allow a leaky expansion tank to stink up your cabin. If a hose near the firewall is split or loose, thats another story.

[KenB]

Expansion tank on m50tu is attached to rad.

I've been noticing a slight smell inside but is stronger outside of car, trying to track it down...

There are a bunch of hoses below the intake...no clamps on them, any of them carry coolant?

[ryan roopnarine]

if you are really trying to rule it out, you could bypass the heater core for a couple of days with a coolant Tee, and see if it persists. its about 30-50 dF here, i do ok without the heat :D

[Dave M]

There are a bunch of hoses below the intake...no clamps on them, any of them carry coolant?

Any coolant hose below the intake has clamps. You might be seeing some hoses south of the throttle body which press on to their respective destinations, but do NOT carry coolant. If you're smelling coolant in the area, you may want to remove, or at least lift, the manifold to get a better look. I had the hose which links the air box to the cylinder head (beside the engine coolant sensor) bust a nut and spew enough coolant to cause a minor overheat.

Best of luck,

Dave M

[KenB]

Thanks Dave, you're right, I just checked realoem diagrams and there are alot of coolant carrying hoses (with clamps) AND some others without.

Everything is dry at the big hose connections on the rad and dry at the heater connections. There looks like some oil or coolant seepage collecting on the nest of hoses below the intake. So far I only faintly smell coolant very briefly while the car is warming up to temp, then it is fine. I suspected heater matrix at first but got out of the car yesterday when I started smelling it and the odor was stronger outside the car than in.

Will have to investigate some more...typically at this time of year my power steering hose connection seeps a little and maybe ends up blowing some mess back towards all those hoses so it's difficult to tell what is the source.

I need to change my coolant but want to make sure I'm not going to lose it all after doing it. I've had to put about 8 onces of water in the system since summer so it is going somewhere...will also have to check the water pump for seepage. The one in there is almost 2 years old coolant was changed when pump was installed.

[brosher]

The heater core is a major PITA to do, but you will appreciate climate control like never before after fixing it!