99 328i smoke coming from intake manifold area

[e36molina]

S.O.S.

So the other day my e36 started over heating on me. I was a bit confused when it happened because I have recently just replaced my thermostat, therm housing, water pump, fan, and just filled my car up with coolant, and still it's over heating. But the thing that is different this time is that when the engine starts to warm I can smell the coolant burning(sweet smell) and once it actually gets hot smoke starts coming out of the intake manifold area. I can also hear a hissing while car is idling. I honestly thought this was definitely going to be a head gasket but no smoke from the exhaust, my oil looks fine, coolant isn't bubbling up, and there isn't and milky substance. Maybe it could be intake manifold gasket? Any ideas anyone? Please help I am stuck and do not know what direction to go in with this problem.

[boarder2k7]

You'll have to look around and see how the coolant is hitting the manifold but since there's no rubber lines over there, I'd say 99% chance it's the head gasket. They won't always produce the symptoms you mentioned in your post, those symptoms are for a failure into the oil passage or into a cylinder itself. The one on my M3 was a leak to the outside of the block on the exhaust port side, at cylinder 3.

[CaptainStark]

Did you "burp" the coolant system after doing the fluid swap? My 525 and 528 both required a couple of burps to get the air out of the system. You'd get a bubble right at the the sensor and it would send the temp toward off-scale high. A quick burp and it was normal. The burp screws are located in a couple high points in the cooling system.

Could you have gotten any excess coolant into the head area by accident? Perhaps hosing it off and then letting it warm up would resolve that. The water will "steam" out of the nooks and crannies until gone. The sweet smell should go away. My 528 had smoke out of the head cover gasket dripping on the exhaust header but that smelled like burning oil. New gasket solved that problem.

You may have a vacuum line open causing the hissing sound but the car would likely idle crappy. Probably not that.

I'd hose it down good and then dry it off with a weedie blower as best you can. Cover the alternator or be careful not to douche it. Then let it warm up and see what happens when it gets up to operating temp. You can burp it then too.

Your radiator fan is kicking on isn't it?

Ray