About a week and a half ago I was driving home from Military duty and the upper hose on my radiator came off, well broke off at the radiator. The idiot light came on but I didnt drive it very far before I could get off the HWY. I relaced the radiator Saturday and everything seemed fine other than the fact that the very next day my water pump went out. Replaced that yesterday and now I am getting a white smoke coming out of the exhaust. It almost smells like water being evaporated but I am not sure. Along with that, every time I start my car, it lopes really bad until I rev it past 4K then it goes away. I drove it for about 45 minutes and hoped that the loping would go away. Stopped, got a beer at the gas station across the street from my apartment and when I got back in, it started loping again but no smoke that time.

It seems to be faster than before which I am not complaning about that but why does it lope like that? And what is the deal with the smoke? I checked the oil and there is no water in it. Also after I put everything back together, There was a real bad knocking sound coming from the vanos area. It went away for the most part after I drove it, but I can still hear a faint knock. Could my vanos unit be going out? It does have 185,XXX on the engine. Any input would be awesome. :help

About a week and a half ago I was driving home from Military duty and the upper hose on my radiator came off, well broke off at the radiator. The idiot light came on but I didnt drive it very far before I could get off the HWY. I relaced the radiator Saturday and everything seemed fine other than the fact that the very next day my water pump went out. Replaced that yesterday and now I am getting a white smoke coming out of the exhaust. It almost smells like water being evaporated but I am not sure. Along with that, every time I start my car, it lopes really bad until I rev it past 4K then it goes away. I drove it for about 45 minutes and hoped that the loping would go away. Stopped, got a beer at the gas station across the street from my apartment and when I got back in, it started loping again but no smoke that time.

It seems to be faster than before which I am not complaning about that but why does it lope like that? And what is the deal with the smoke? I checked the oil and there is no water in it. Also after I put everything back together, There was a real bad knocking sound coming from the vanos area. It went away for the most part after I drove it, but I can still hear a faint knock. Could my vanos unit be going out? It does have 185,XXX on the engine. Any input would be awesome. :help


No idea, but generally I would say it is a big no-no to drive your car around with smoke and noises, if you have no idea what you're doing. Take it to a mechanic...

once the magic smoke comes out...theres no way of putting it back in... :eek:

I do know what I am doing but I would like to get input from other people that are knowledgable about BMW's. I am a DIY type and if I or someone can help me diagnose the problem, then I would like to save the money. If anything I will swap in my 3.2 but that will be the last resort. The smoking has subsided but the loping is still present. And from what I have read, the vanos does make noise naturally and since I have a CF hood with no insulation on it, then the noise will be heard from inside the cockpit.

Is there anybody out there that wants to help instead of making comments like the one above?

Bump cause I need help!

Um check for milky looking oil and/or oily coolant. Sounds like you might have warped the head.

Since nobody's answering I am going to guess you blew a headgasket. The radiator failure is very typical, and you may have driven farther than you should have after the idiot light came on. What was the temp gauge registering at the time? A blown head gasket is not ALWAYS accompanied by coolant in the oil. It depends on where the failure is.

I'd quit driving the car and do a leakdown test and compression check on it.

I checked the oil and the coolant and everything looked fine. There are no leaks on the head or anywhere else for that matter. I did however find a cracked intake boot aft of the HFM. The car is chipped and I was thinking that if the chip is telling the engine to suck more air when there is air getting to the engine that isnt being registered by the HFM then that would cause a lope of some sort. Does that sound somewhat correct. I know what I am talking about but cant seem to find out how to type it out. As for the temp, it got about 3/4 of the way up. Which is hot but not dangerously hot, right?

That doesn't sound like it got overly hot. The air leak could definitely cause erratic running. Seal it up and see what happens. The air leak wouldn't cause the smoking problem, though. The symptoms you described say warped head/blown head gasket. Again, there isn't always oil/coolant mixture, and you wouldn't always be able to see an external leak.

Well it didnt smoke this morning and the knocking has subsided more. Now that I think back there has been a lot of rain where my car sat for a week and I believe that it was just the evaporated water that was coming out of the exhaust. I ordered a intake boot yesterday and it should arrive tomorrow. I hope that this fixes this. If not I will have to do my motor swap earlier than I wanted to. I wanted the 2.5 to last for 200,XXX, hopefully it does. Wouldnt a warped head mean that the head gasket would be blown? How else would you find a leak if there is one?

I don't know about figuring out if the head is warped other than having a mechanic measure it, or whatever they do. The excess temp is very likely air in the coolant system - you need to bleed the air out by running the engine, turning the heat in the cabin up high, and removing the bleed screw on the radiator till all the bubbles are out.

Yes, a blown head gasket could be a symptom of a warped head. But a blown head gasket is not ALWAYS the result of a warped head.

two possible causes, blown head gasket or cracked head. nearly every time i pull a head for similar complaints on m50 motors the head is cracked.

Head gasket or some type of head problem (crack?). I am working on a technical article on this replacement right now - should be done very soon...

-Wayne