??Heater Smells Sweet & or Like Burning Smell??

[1995 540i]

Hey guys, so here goes my second post. I have a 1995 e34 with only 80k on the clock. It’s been getting colder out and I notice when I turn the heat on it smells like something sweet and or a burning smell. And I do tend to get the fog on the windows. The car does smoke a little (white) on warm up but nothing bad at all due to the temperature & then goes away once the engine is warm. The previous owner had a new radiator installed in 2007 and I have noticed a small radiator drop in fluid say every 500miles. There are NO signs of leaking anywhere and before I got the car the head gasket was replaced. So im thinking I need a new heater core but just wanted to ask some advise since I hear it’s a pain in the ass to do and cost a lot if I take it to the dealer to have them do it. Any thoughts or suggestions?? Thanks :-D

[Russell]

fog on your windshield or sweet smell may be due a leaking heater core. Burning smell may be due leaves etc geting into the heater fan. Consider contacting a good independent bmw repair shop. I hear it takes 6-8 hours of work to replace the heater core.

[genphreak]

If the cooling system has been cared for (coolant not left unchanged for years and years and the correct coolant used) then most likely the only problem will be the o-rings are leaking when changing temperature. The pipes and the core can require replecement but have to be suffering from wear and tear- if salt water got down into the core from the windshield at some point,... maybe. I have never had to do a core replacement, but have replaced the o-rings many times. It isn't as hard as you might think, removing the console to get at them. It just takes care to do it without breaking the fasteners and the plastic mounts/clips etc. For a DIY, task it will only take a day the first time if you get an early start and have a good selection of screwdrivers.

You start by removing the centre console, then
glovebox,
all the dash panels above the footwells
radio and heater controls
the whole main console
and you then have access

... also plan to do the cabin filter whilst you are in there.

The biggest problem w the job is that it requires a level of contortionism I dislike.

[1995 540i]

guys thanks for your input....might take this one on myself, or might take it to local bmw. Not sure yet, but sounds like its a project.

[genphreak]

So its a day the first time if you lose enthusiasm- but don't be dis-heatened. I can do one go to whoa in 5 hours without going fast about it. I doubt a dealer or an indy would even take the job on really, they just don't like that sort of thing much.

[1995 540i]

yea guess ur right... ill keep ya posted and let u know how i make out...

[Tiger]

Got the same car... had that problem for a long time... the leak is the heater hose underneath the coolant reservoir. Take out two plastic nuts to loosen up the coolant reservoir... move it aside and see if any of the heater hoses is leaking underneath.

Mine as I discovered was a leaking heater hose that you cannot even see unless you remove the coolant reservoir.

Second thing is make sure you got a 200 radiator cap... not a 240. 200 cap is flat... no bump in middle.

[632 Regal]

They do make a powder sealant guaranteed to not clog the heater screens on newer Cadillacs, I used 1/2 tube a few years back and it helped a lot. Starting to smell it again so I will add the other half when I flush it this season. I know it's not the right thing to do but it did work lol.