Sweet smelling white smoke coming from my exhaust.

[han]

There a little smoke coming from my exhaust which smells sweet. Am I looking at a head gasket replacement here?

I was meant to take a 800mile road trip but i'm a little bit concerned about this smoke. It occurs mostly when i first start up but seem fine after that. However I'm very scared of long trips since my engine broke two months ago with a failed intake manifold diaphram letting oil into the engine. Could this be the signs of my Nikasil engine on its way out?

[bimmerd00d]

sure sounds like it. :(

[LMUNick]

Sweet white smoke can only mean one thing- coolant. And the reason it seems to go away is that the engine expands as it heats up and helps close any leaks in the gasket. Hopefully its not a cracked head!

[han]

What do you think I should fix? I am an engineering student so have alot of spare time in the summer and do like to fix everything i can. Plus my granddad is a mechanic so I have all the tools for anything. Is there anything i should do before my 800 mile road trip? Would I be stupid to go this far? what will i tell my girlfriend about the trip? she doesnt take kindly to changes of plans :(

[LMUNick]

I am not overly familiar with the V8 motors and what can be done about the nikasil leakdown issues, but as far as the burning of coolant-I'd say headgaskets. Get the heads pressure tested just to be sure while they are off. Do the waterpump while you are there. If your grandpa has all the goods, go ahead and do a leakdown and pressure test as well, as this will help identify any other possible issues, rings, guides, etc...

Anyone else feel free to jump in-

[632 Regal]

Han, you should really list the year, mileage and model car in your name or signature for the other posters to see what car your talking about.

Now... the smoke that goes away doesnt mean anything as of yet... do you have to add water (antifreeze) periodically? The smell could simply be the cats heating up and condonsation developing.

I havent heard of ANY V8 losing a headgasket...the real mechanics will know more than me about that though.

Your Nikasil fear is almost unwarranted here, chances being very much in your favor that if it hasn't failed yet...it shouldnt.

The failed diaphram is simply a glorified PCV system not a sign that the actual "engine" is toast.

If you want to get creative here, closely inspect all the connections to the intake side of the manifold for leaks and or cracked tubing/hoses...any ANY intake leak can cause a miss or stumble that will almost ALWAYS be diagnosed as a Nikasil failure.

just my 2¢

[han]

Sorry I just signed up and forgot all the important signiture stuff and photo. The car is a 1993 530i auto with 176 000 miles.

I drove the car just now and its seems ok, power seems as good as always, so I'm a little less worried. Still concerned about the 800miles trip. There a few idiots out there who think my car is unreliable after the last incident, which was bad because i spent the whole journey going on about how reliable my new car was going to be, up until a thick cloud of smoke started apearing out of the back window.

[632 Regal]

thick cloud that you can see through the rearview window???

that is NOT a good thing!

[han]

That was before when the diaphram went and oil was being squirted into the engine. I got that sorted out only 30pounds for the part and ten times that for the labour(was too far away from home to get it towed cheaply) Its doesnt smoke like that anymore but now everytime i see anything that looks like smoke i get worried, i've almost lost faith.

[632 Regal]

do you lose coolant?

[DanDombrowski]

What kind of engineering?

[han]

I think it was mostly just oil that i lost last time, i sent it to a bmw specialist and they filled it up wit all the esential liquids.

Dan I do Electrical and electronic Engineering. Not really that usefull for fixing mechanical faults but good for the electrical stuff.

[632 Regal]

I mean are you losing coolant NOW...trying to see if your car is normal or not.

[han]

The coolent is a little low now i'll refill it and see how quickly it goes down.

[LMUNick]

632 Regal-
Good call on the headgaskets. I did some reading and didn't find much as far as common failures. I am going off similar symptoms from other cars I have owned. Despite some prodution flaws from time to time, these motors are pretty bulletproof-

I still worry about the smoke from the pipe though, especially if it has the tell-tale smell.