Foaming Windshield wash fluid? Service Engine light illuminated!

Just bought a 2003 325i. I took it to the dealer for the Inspection2. I brought it home with no problems, but when I went out to the garage later that night I noticed a very slight anti-freeze smell. I
couldn't find any leaks under the car and nothing jumped out at me when I opened the hood. The next day after a 1 1/2 hour drive the Service Engine Soon light illuminated. I opened the hood and noticed that the windshield wash fluid was foamy and looked like it had overflowed the reservoir. That is reservoir is not pressurized, is it?
The dealership had nothing to say about the washer fluid, but did try to sell me a new environmental sensor.
Anyway, does anyone have any ideas on how this would happen. I've never seen anything like it.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Methinks it is the coolant reservoir that is "foaming" and you have a head gasket leak. Service engine light tends to confirm you actually have a major fault, but check security of coolant cap, coolant level and oil.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The dealer SHOULD top off the windshield washer reservoir with BMW's fluid (better than most discount auto store brands). It shouldn't foam. The tank isn't pressurized.
Another Insp 2 thing is to check all fluids and top them off (they REALLY should drain and refill diff, trans, P/S steering). It's possible that they didn't snug the coolant cap and it lost some fluid (the cooling system is pressurized) or perhaps they were more thorough and bled the system and didn't get the bleed screws tight. This link has some good pictures of the coolant system in an E46. http://www.bmw325i.net/maint_coolant_level.shtml
The "Service Engine" light is related to emissions stuff, although other failures can indirectly lead to it lighting up. Best follow its advice. Take it to the dealer, have him dump the codes from OBD. And I'd have them give the cooling system a careful exam including a pressure test.
BMW uses pretty poor quality parts in their cooling system. Water pumps are notoriously short-lived (60-100,000 miles). The radiators will also tend to fail (75-120,000). Your '03 has an electric thermostat ... not sure about its longevity.
Is the car CPO? That would help if there really is something major going bad.
R / John
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.