Steam from under hood, but no leak?!?

[jfischetti]

Hi again,
I am getting steam(smells like coolant) coming out from under the hood after driving with a warm engine for 20 minutes or so.
There is no visible leak anywhere. Could the radiator itself be giving off steam simply because it is so hot and the air is about 30 degrees? The needle does not go past the halfway mark.
I have a new thermostat and waterpump.
Thanks for reading,
J

[AaronM3]

hmmm... .check the underside of the coolant tank for any leaks. Then i suggest taking a sharpie and marking on the tank your coolant level. Going for a drive... coming back and checking the mark to see if you've lost any coolant.
Lastly where does the steam specifically seem to be coming from in the engine? Down below or up top?

[badmonkey]

AaronM3, please contact me.

[M3inSC]

The neck on the upper radiator hose could have broken off and be blocking the coolant flow. You will not see a leak, but your call will be overheating almost immediately. Check out that radiator now!

[abakos]

Reservoir cap? Just throwing it out there-- They're made to maintain a certain pressure...if it has failed it could be a contributor?

But maybe I just don't know what I'm talking about-

[Des]

What just happend to a friend of mine and could be happening to you is that there is a small bleed screw on the rad and on my friends car this had cracked / broken and when the rad was hot and under pressure the steam and coolant where forcing there way out, it would be worth checking this out and the part is only a couple of dollars.:

[M3inSC]

Originally posted by Des
What just happend to a friend of mine and could be happening to you is that there is a small bleed screw on the rad and on my friends car this had cracked / broken and when the rad was hot and under pressure the steam and coolant where forcing there way out, it would be worth checking this out and the part is only a couple of dollars.:

That's right! I saw that happen to another M3 at the track last fall. Look up under your hood over your radiator cap and see if there is coolent there. If there is, check that the bleed screw is tight and not leaking!

If you are not overheating, it is probably not a broken neck on your radiator.

[jfischetti]

Thanks Guys, but It has not happened again...
I do smell coolant from time to time, but I haven't seen any steam lately...
I checked all of your suggestions, you all had great ideas.
Go figure
Fish

[NoSoup4U]

If you have access, take some UV dye, add it to your coolant, drive around, take a blacklight and go under your car....that should illuminate any leaks, if there are any.

There's no coolant in your oil right??? You are not blowing any white smoke at any time from your exhaust?? The HG is not leaking coolant...

I think the UV dye is your best option at this point, especially if you still smell coolant. UV dye can be picked up from any car repair shop....