Test Drive: Smell of Coolant Coming From A/C
 

I am in the market to buy a E46, today I test drove a beautiful 2002 325xi, I noticed two things that made me uneasy.

- The sunroof can open about 95% of the way but trying to open the other 5 will result in a clicking noise

The sunroof slider seemed to be working well though

- There was a slight smell of coolant coming from the A/C, my guess is that this is really going to end up being a huge problem with the heating core or something, is this true?

using the sunroof can have the sunshade sliders fixed or moonroof reset where it's getting hung up.

i am not sure about this one. but yes, often that indicates the heater core is leaking somewhere inside on the interior fan condensation tray and that's why you smell coolant. but this could also just be mildew on the tray from the A/C and needs to dry out or spray some dis-infectant on it if that's it.
so basically i'm saying be sure it's coolant smell before figuring it represents a probable heater core problem.

The coolant could also just be a cooling system leak...and you're smelling it because the air comes through the cabin air filter under the hood. It could be a huge problem...not if it's just a cooling system leak, but if it's a sign the cooling system hasn't been maintained or the car overheated, had head issue, and that's why the owner wanted to get rid of it.

Many sunroof issues can be fixed, but some really require a pricey fix. Also, so you know, they never open all the way back anyway...but the clicking isn't a good sign and might require more than just a couple little parts.

Realoem.com is where you can see all our parts and their prices (at the dealer).

Trust your instincts. There are bmws for sale without such issues. They'll have other issues though. Also, they'll all pretty much need work to get it to drive as good as new...suspension/bushings/pulleys/cooling systems/gaskets...they all need work. After you read more fanatics, you'll have a better idea of what to expect and when to expect it.

Hold back maybe 25% at least of what you can afford to spend on a car for repairs...and you really can save tons by diying. A whole cooling system would cost me $300 in parts (more with radiator)...but the dealer would charge easily over $600 for the same parts and another thousand to install them. So if you're not prepared to diy, I hope you have both money and a back up car. Not to discourage you...too much! Sorry for being the one to say all this.

Read up on head gasket issues and how to spot them. Look for date stamp on ET...if it's new and you smell coolant...you want to find where it's coming from. Probably not the heater core though. I can't recall reading a thread here where the heater core leaked...and I read a lot!

Thanks a lot for both of your replies, looking at the service records, I see that she had the expansion tank replaced a little over a year ago, and back in 2009 there was about $200 done in "cooling system repairs". I don't really know where to proceed unless I take it in to some shop and ask them whats wrong.

I always suggest a PPI done to any E46 (car) prior to buying. These cars especially can have unseen things needed that can be well over half the price of the car. Not trying to scare you. As there are plenty fine examples out there too. But just don't jump into anything without finding out as much as you're able.
And a "Pre Purchase Inspection" can save hundreds to thousands.

Has anyone else experienced the smell of coolant coming from the A/C?

I've had the smell of coolant, but I thought I said it wasn't coolant smell coming from the AC, as AC per se. Coming through the cabin air filter mounted under hood...which sucks air in for either AC/heating or vent. You could try hitting recirculate with windows open and see if you still get that smell. If it's coolant, you won't...that is, unless it's from the heater core leaking, and that's very unlikely.

But, you may be saying coolant and meaning 'refrigerant' ...and if so, I don't know what R134a smells like.

Or, you may have just what we call 'smelly sock smell' from mold, bacteria, and maggots growing in your hvac housing. I get that still, and sometimes pretty badly...but mitigate it by turning off ac and blowing fan high for a few mins. at least before stopping car.

If your heater core is leaking I'd be surprised.

Edit: sorry forgot you hadn't bought car yet. I've smelled coolant and it was because I had a leaking coolant system...the solution is pretty widely accepted to be replace $300 worth of parts...but it could be more than that...and it could be more serious than that.

Get that PPI done...have them look at subframe in particular even though Xi seems pretty resistant to that issue.

Also, have to say that an i>Xi if you don't need that extra axle for serious snow or off road racing...and Xis have issues with front axles pretty often too I read. Check Xi subforum.

Sorry for forgetting which thread this was!

I really appreciate all your help! I have heard that the i is better but because of the amount of snow down here I think it's something to have, the seller has provided me with some pretty good documentation of the services and shows that the front axles have already had a couple hundred in repairs so I'm hoping it doesn't give me to much trouble. I'm going to get a PPI inspection this week along with a state inspection. I hope everything works out, the car is a real beauty and I hope it stays that way! I'll report back with what I hear.

the air being drawn in should not be from the engine compartment. that section is fairly well segregated and draws air from the hood vent out.

i personally have not smelled coolant from the air vent with AC or outside air. whenever i have smelled coolant is was when outside car and most often if it hit the exhaust.

if concerned about the heater core look down at the inside firewall/console area. if you can smell or touch there i then would be worried. coolant doesn't evaporate and would make carpet feel a bit wet-greasy.

you could also run the heater and see how that smells. the coolant will run through the heater core area then and could give up some evidence too

That's a good point about air filter being sealed from engine...hadn't thought about that...though, having seen many cars, I know many have missing or poorly 'linked' gaskets...so I doubt it's an air tight seal.

Good luck OP...let us know what results you get...and maybe we'll give you a good angle to negotiate from!

Alright, I just got took the car to a BMW dealership for a PPE, they shot me $2k for fix a bunch of stupid stuff I can do for about $500. I told them about the smell but they didn't find any problems about the cooling system. What do you guys think?
Thanks

Well if an AWD car is what you need. Does the price seem good and what are the options on it and mileage on it? You really didn't tell us much about the car other than it's a 2002 325xi and looks good with some previous fixes on cooling system and front axles. From what you said by it checking out in the PPI it seems good, but for some more indepth review of the car we kinda need more.

You mind posting what dealer said it needs?

Thanks for the reply, it's a 2002 325xi with 96k miles. In terms of options it has both the sport and premium package. The car cosmetically looks pretty good. She had the car for 5 years and serviced it at the BMW dealership and dropped about 9k on maintaince and repairs, she had all the records organized. So by this it seems good. Previously I had a Saab and an Audi both that had this crayon smell coming from the AC just like what I'm noticing with this car so I don't want to jump into to a mess of repairs because it was pretty expensive to do on the other cars.

I don't have the report from the dealer in hand but it was small stuff like regulators, pads, and replacing the headlights because they looked foggy. I'll post the report asap

Here is the report i got from the dealership: http://i.imgur.com/LQaFc.png

Oh lord...that puncture in seatbelt...I wonder if that's just the hole where that tiny 'nib' goes to hold the buckle in position. If that's missing, there will be a puncture. If that's it...for shame dealer!

If you don't have a pad warning light, then I suspect that the 4 corners of pads and rotors might be bogus. Not sure why the brakes failed though.

Headlight being foggy sounds bogus also...you might be able to get new lens covers like I got for mine--$80 for both at rmeuropean. Not sure if later models allow this.

If you do not smell it outside the car, but only inside; run and find another e46.

Yeah the headlights can easily be fixed with some sandpaper and some other stuff no problem, it wasn't that bad at all when I saw it. The only thing that catches my attention is all the brake work..

If you don't have a pad warning light and the car stops, then you don't need any brake work...that is, unless they said that the side without the sensor is seized and the pads are worn down there. In which case, they would have said you also need new calipers...I'm pretty sure. Dealers are like that.

When my pad sensor went off...I had about 1.5mm pad left when I did the work 700 miles later.

Also, rotors can usually take two sets of pads no problem. Measure the rotors yourself and see if they're above minimum thickness, which I bet they are. $10 micrometer is all you need.

If the rotors are worn right at the edge/limit of minimum thickness and you put new pads on, what do you think will happen after driving a few hundred miles? You're at below minimum thickness and wouldn't even know it.

Replace rotors once the pads are exhausted.

^ that's true enough, but two things...one, I've heard that the minimum thickness or above is okay to put new pads on...my impression is that above the minimum thickness means 'okay for new pads,' but I could be wrong...and I know you think I am! LOL

In any case, when I measured my rotors after 60K miles with totally worn out pads, my rotors had only worn halfway between new and minimum. There's a lot of life in those rotors. But, a shop/dealer preying on unsuspecting/knowledgeable owner might well say the brakes are an issue--that's a suggestion that's hard to ignore!