Hey everyone,
I think I know whats wrong here but I wanted to see if some people could confirm my suspicions. I have a '05 S with 42K and just yesterday when I was pulling the car in to the garage to do an oil change I noticed an ammonia type smell coming from somewhere. I didn't really think too much of it. This morning I start my car up and let it warm up for a few minutes and go back inside. Then I go out and as I'm walking out to my car I see my exhaust is heavier/thicker than normal. I bend down by the exhaust tips and take a little whiff of what's coming out of the tailpipe and sure enough a very strong odor similar to ammonia. So I start watching it as its idling and every couple minutes there's a one second to two second little puff of white smokish vapor. I say smokish cuz its not really a thick smoke at all and dissipates after 15 seconds or so in the air. So I stick my foot in the car rev the engine a little bit and some more comes out but after 10 seconds or so holding it at a steady rev it clears up. Then after idling for a minute or so little puff's come back. Also while driving I dont ever notice any type of smoking coming from the rear of the vehicle either. FYI I had a spark plug pop out on me in February and had to have a time-sert installed along with new Brisk plugs. Not sure if that's related or not but thought I'd mention it. What does everyone think??

Steve

 

Anybody got any ideas?? I think I panicked and posted this too early this morning (east coast) and didn't get the rest of the country to see it. Hope someone can help me out. I'm probably going to call the dealer tomorrow and setup an appointment to get it looked at.

Thanks,
Steve

 

Is the smoke looking stuff 'smoke' or is it water vapor?

Is your coolant level where it should be? Mark the res with a marker so you can watch it.

Does your oil have any milk shake crude in it?

YD

 

no not water vapor cuz it lingers in the air longer than vapor does, coolant level might be a tad bit low...my bottle is so yellowed that you can't even see the fluid in the bottle but by taking the cap off and comparing the level to the side it seems to be a bit lower than the min level at cold temp. No milky oil in fact I just did an oil change, that's when I first noticed the smell (when I was pulling the car into the garage).....just afraid the head gasket may have a crack in it and the coolant could be seeping into the combustion chamber. Anyways I did a little googling on "ammonia smell from exhaust" and got forum after forum response pages on catalytic converters going bad and giving off that particular smell. I took the car for a ten minute drive earlier and although I couldn't get it to give off the little puffs of white smoke, the exhaust has a distinct cleaner type smell, just without the nostril burning sensation of ammonia. Since no one else responded to me, what do ya think Yo??

Steve

 

It all depends upon how much you want or can do yourself. Borrow or rent a compression leak down kit. That will tell you if you have a bad gasket. You can also do a pressure test on your coolant system.

I would keep watching inside the oil filler cap for milkshake. I would carefully make a little homemade dipstick out of anything and each morning before you start the engine, carefully measure the level in the coolant res.

A small block or head crack will sometimes seal up when it gets hot and open when it gets cold, which allows a small amt of coolant into a cylinder overnight causing the white steam, but if you are totally sure it is not water vapor, we may be barking up an MT tree.

Are you sure it is an ammonia smell and not a sulfur smell like rotten eggs? Some cats will get into a reducing mode instead of an oxidizing mode and make various sulfur oxides which stink.

Just keep watching everything very carefully and stay in touch.

YD

 

Thanks man,
I should definitely look into borrowing one of those tester kits and start from there. How do people keep an eye on their coolant level if those stupid bottles cloud over so easily?? I know some people run those aluminum tanks but again same thing, you can't see the level inside right? I've seen a car drive with a blown head gasket and I know its basically a vapor but its really white and it lingers around longer than say steam would, that's basically what is happening but in very very small intermittent amounts and really only when the engine is hot. I had the car idling out in the driveway for almost ten minutes the other morning when I went out and noticed it. Last night when I went out for a drive it wasn't doing it when it was cold but it did have a strange odor to the exhaust, definitely not normal. It's also not the sulfur smell either. I've smelt that many times from other vehicles and its not that rotten egg smell either. Its really a cleaner type smell. I'm just gonna have to do like you said, just keep an eye on things and watch it.

Thanks,
Steve

 

when it's cold ; pull the plugs and look for coolant . also is it stumbling when it puffs?

 

There are a number of threads about engine smells. This is one that summarizes different odors even though the original question is somewhat different.
https://www.northamericanmotoring.co...eleration.html

One that is not mentioned there is the ammonia (NH3) odor. Your cat does a number of things and one of them is to reduce NOX's (nitrogen compounds) and as they are broken down you should be getting N2 (nitrogen), H2O (water vapor) among other things.

I would suspect that certain formulations of gasoline, either gasohol (10% or so added C2H6OH "ethanol") or so-called oxygenated gasoline (a smaller amount of alcohols) would be a likely culprit in your case as the basis of ammonia as the Nitrogen compounds with the split alcohols combine to make NH3.

Try a different gasoline that is not gasohol or oxygenated.

 

Herbie: I'll try and pull the plugs, but to be honest it hasn't done it since that morning. I've been keeping an eye on it, smelling it and so far nothing..but definitely going to monitor it.

Cigar: I am starting to lean toward the oxygen gasoline cuz this past tank I went to a Mobil station I hadn't been to with the Mini so maybe that was it. The exhaust does continue to have a cleaner type smell but no smokish vapor.

Just one other thing......how the hell do people see with these horribly manufactured coolant reservoir bottles? Like I said before, mine is completely yellowed and clouded over and even with a flashlight cannot see the fluid inside!! Do the aluminum tanks have a sight line inside of it, or does someone make a more opaque whitish colored bottle?

Thanks for the info guys much appreciated!

Steve

 

When cold, first thing in the morning, open the cap and dipstick it. Keep records.

YD

 

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