exhaust fumes

[Sam SL]

My car runs well and strong.  I want to know if others experience what I do.  That is, when I drive with the top down and the car comes to a stop from cruise, I often get a whiff of exhaust fumes.  The smell is strongest just as the car stops, then gets more faint as it idles smoothly.  Do you guys get that with your cars?  Do you always smell some exhaust when you back into your garage?  Is this all normal and I am just hyper sensitive to the smells that modern day cars don't spew out anymore?  By the way, I have the CO set at around 4.75 at idle (in gear).  Any lower the car stalls at idle.

[Cees Klumper]

I believe I very seldomly smell the exhaust when driving with the top down, certainly not every time I come to a stop like you describe. Maybe when backing into the garage, but even then I don't recall noticing that really. I set the CO at around 3,5 at idle in neutral, no problem running at 800 RPM at that level, unless the engine is cold, then it will hesitate just a bit. Maybe your mid- and/or higher range CO level, or your ignition timing, valves adjustments etc cause the smell. How is the fuel consumption (can't really call it fuel efficiency)?

[Sam SL]

The consumption is around 16 MPG mixed highway/city, or around 17.4/100km.

[Eryck]

I have a similar issue but not sure if it's just when I stop the car.  I know that after every drive, my clothes smell like fumes.  Still trying to figure out what the problem is.  Maybe fumes are coming from the engine bay and the insulation is an issue....no idea yet.

[mdsalemi]

Sam,

Compared to most modern drivers, this car stinks--literally.  Just like using a 2-stroke weed wacker or leaf blower, and finishing your project smelling like a refinery, after a drive in my car--which does not burn oil or anything like that, and is in reasonably good tune with only 10K on a rebuilt engine, I stink like gas and oil.  Maybe you and I have keen senses of smell.  My modern drivers make no gas or oil smell or anything like them, at all.

It is an inefficient engine that generates a lot of fumes/pollution; the top-down method of driving swirls these around the passenger compartment.

Do I experience what you do?  Heck, yes.

I should add (so as not to offend anyone) that the emissions are probably not unlike those of other similar vintage cars.  Should also note that the "factory spec" on oil consumption is, compared to modern cars, a bit high.  Another contributing factor is the additives and blends of fuel.  On my first trip to Germany in 1971, the very first thing I noticed (aside from the fact that most taxis were MB's!) when walking out of the Frankfurt terminal was the difference in exhaust smells.

[hands_aus]

quote:Originally posted by mdsalemi

Sam,

Compared to most modern drivers, this car stinks--literally.  Just like using a 2-stroke weed wacker or leaf blower, and finishing your project smelling like a refinery, after a drive in my car--which does not burn oil or anything like that, and is in reasonably good tune with only 10K on a rebuilt engine, I stink like gas and oil.  Maybe you and I have keen senses of smell.  My modern drivers make no gas or oil smell or anything like them, at all.

It is an inefficient engine that generates a lot of fumes/pollution; the top-down method of driving swirls these around the passenger compartment.

Do I experience what you do?  Heck, yes.

I should add (so as not to offend anyone) that the emissions are probably not unlike those of other similar vintage cars.  Should also note that the "factory spec" on oil consumption is, compared to modern cars, a bit high.  Another contributing factor is the additives and blends of fuel.  On my first trip to Germany in 1971, the very first thing I noticed (aside from the fact that most taxis were MB's!) when walking out of the Frankfurt terminal was the difference in exhaust smells.

Hey Michael,
There must be something wromg with my 250sl as I don't have that fuel smell after driving my car.  
Strange that it doesn't have any fuel smell at all, maybe I have something to look forward to.  

[graphic66]

My 230SL doesn't leave you with any smell or unpleasant fumes when driving, top up or down.

[mdsalemi]

I think I have a very sensitive sense of smell; perhaps Sam does too.  EVERY car of this vintage (and I see [and smell] plenty what with all the car shows around here every day of the week), has a peculiar exhaust smell.  Modern cars do not because they have more efficient combustion and cat converters.

There's science behind it too.  The average car today makes so little emissions that many have stickers "LEV" in their windows.  The standard oil consumption of the W113 according to the book is considerably greater than that of a modern car, too.  Where is this oil going?  Well, some will tell you on the garage floor but realistically it is being burned.  Not at a level to cause blue smoke in a good condition engine, but burned nonetheless.  Sorry to say, that burning oil creates an odor.  That, and the inefficiencies of unburned fuel (it's not a modern Honda engine, guys and gals, but a 50 year old design) lead to the smell I speak of and Sam as well.  With all the talk of mods, I've never heard anyone suggest a cat converter.

Top down makes a difference: without a windscreen, there's a lot of wind blowing from the back and that contains these exhaust fumes.

Just because YOU don't smell it doesn't mean I don't or that it isn't there.

[kingston]

I have the same smell issue with my 69 280sl. No smoke and no oil burn, garage said no particular problem.

[Mike Hughes]

We have gotten used to the odorless exhaust of our modern daily drivers, haven't we?  Just goes to show what advances have been made in emissions technology in 40-odd years, that a clean running Pagoda engine would smell like a foul running modern engine!  ;^)

[66andBlue]

quote:Originally posted by mdsalemi

I think I have a very sensitive sense of smell;...

Follow the lead, plug your nose!    

[Sam SL]

Well, I've done a bit more tweaking with the car and getting some positive results.  The odor is definitely less and with my sensitive nose I can still smell the polluted air around my car.  I suppose it's like in the old days when I was around cigarette smokers, even indoors, and it was no big deal.  Today, I detect the foul odor within 20 feet of a smoker even when I'm outdoors.  

Anyway, back to the car, I have the carbon monoxide (CO) set to 5% at idle out of gear with the hydrocarbons (HC) at around 380 ppm.   That's down from an earlier CO reading of 7%.  Here's a fact that supports much of what have been discussed about modern day cars:  My 91 300E turns out a CO reading of 0% and HC reading of 17ppm at idle.  That's progress.... even if only a 91 car.  I wonder what an 08 car would achieve!