The Ford Barn

bikemaniac · 08-03-2015, 05:29 PM

Hi,
I have clocked some 700 mi in my Model A now, however there is an annoying smell coming from the engine or the exhaust and I cannot locate it.

1. The smell sort of annoys my respiratory system and makes my throat dry. However it first starts after about 1h of high speed driving. I just feel that it is not healthy at all.

2. I have a hard time describing the smell. It is not 100% gasoline, nor 100% exhaust. Something in between maybe.

3. When the car has just been started, there is no smell.

4. After 1h or so as highway speed such as 50 mph, it is particularly noticeable when I reach a red light and the engine idles. I sort of also feel the smell is there when the engine really has to work. Babying it at 30 mph does not seem to give any smells.

5. I drive with my windows open because it is hot outside.

6. I have just replaced the exhaust manifold and used high temp sealant everywhere to really seal the exhaust off everywhere.

7. I know from modern cars, if you drive with your trunk open and have the front windows open, you will get exhaust automatically into the car by some vacuum mechanism. Might that be my problem? Because the exhaust ends at the rear axle which is basically below the rear seat and thus exhaust gasses can be drawn inside due to a vacuum?

If I cannot solve this smell issue there is definitely not going to be any USA road trip for me :-).

I was told to put a filter into the oil filler tube to avoid the oil aerosols hitting the engine and heating up = maybe causing the smell. I tried it, but is does not seem to solve the problem.

Any suggestions?

Lucas

RandyinUtah · 08-03-2015, 05:53 PM

This might seem off the wall but I have seen when a mouse moved in to muffler and made a nest or died. It took some time to burn the smell out of the exhaust system. Just a thought.

700rpm · 08-03-2015, 05:56 PM

It might be your sealant burning off. It might be your manifold gaskets are not fitted properly. Unless you put on a brand new exhaust manifold, it might be warped and not sealing properly. It might be blow-by from the crankcase escaping out the oil filler tube. There is a special cap made with a hose that redirects those fumes out below the car (see Bratton's or Snyder's web sites). That's about the best I can suggest from 10,000 miles away.

It is unlikely being sucked in from the exhaust pipe itself.

Brentwood Bob · 08-03-2015, 06:01 PM

exhaust pipe should extend about a foot past the bottom of the curve over the rear axle.
Could also be curing out of the copious sealant, or if you repainted the intake and exhaust or the muffler assembly.
No weeping at the steering column attachment to the gas tank, or the shutoff under the tank, or the fittings to the sediment bowl?

Mitch//pa · 08-03-2015, 06:14 PM

do you hear an exhaust leak??? it should be very easy to detect

My1930ModelA · 08-03-2015, 09:26 PM

Sponsored Links (Register now to hide all advertisements)

Could be crankcase vapors from the oil filler breather. I also own a 1958 car and the crankcase fumes from this pre-PCV valve and other emission controls car are really strong. Just how it was back in the day.

My1930ModelA · 08-03-2015, 09:28 PM

Model A's also dont have a road draft tube to draw out blow-by crankcase fumes. They just spew out of the oil filler cap.

fiddlybits · 08-03-2015, 10:09 PM

Floorboards are heating up. Problem area most likely by carb / exhaust.
I attached an aluminum panel with screws, using some nuts for standoffs, to the underside of the floorboards and my 'hot smell' went away.

Y-Blockhead · 08-03-2015, 10:54 PM

Quote:

Originally Posted by My1930ModelA

Could be crankcase vapors from the oil filler breather. I also own a 1958 car and the crankcase fumes from this pre-PCV valve and other emission controls car are really strong. Just how it was back in the day.

Quote:

Originally Posted by My1930ModelA

Model A's also dont have a road draft tube to draw out blow-by crankcase fumes. They just spew out of the oil filler cap.

That was my thought also. Mike's (and others) sell a oil breather http://www.mikes-afordable.com/product/A6764.html that directs fumes below the car and acts as a road draft tube to help vent the engine of unburned fuel and combustion byproducts and other nasty shtuff.

H. L. Chauvin · 08-04-2015, 02:59 AM

FWIW:

Always difficult to solve from miles away .... all above replies very possible causes.

With windshield open, and "if" your gas tank cap is loose, rising gasoline evaporation vapors in hot weather could enter through the open windshield while traveling ........ or when stopped with engine fan blowing air out of sides of hood ..... mix this with engine blow-by out of the oil filler cap and you may have a "recipe" for a "mixed" odor.

08-03-2015, 05:29 PM	#1
bikemaniac Senior Member Join Date: Aug 2013 Location: Copenhagen Posts: 177	Exhaust smell in car during driving Hi, I have clocked some 700 mi in my Model A now, however there is an annoying smell coming from the engine or the exhaust and I cannot locate it. 1. The smell sort of annoys my respiratory system and makes my throat dry. However it first starts after about 1h of high speed driving. I just feel that it is not healthy at all. 2. I have a hard time describing the smell. It is not 100% gasoline, nor 100% exhaust. Something in between maybe. 3. When the car has just been started, there is no smell. 4. After 1h or so as highway speed such as 50 mph, it is particularly noticeable when I reach a red light and the engine idles. I sort of also feel the smell is there when the engine really has to work. Babying it at 30 mph does not seem to give any smells. 5. I drive with my windows open because it is hot outside. 6. I have just replaced the exhaust manifold and used high temp sealant everywhere to really seal the exhaust off everywhere. 7. I know from modern cars, if you drive with your trunk open and have the front windows open, you will get exhaust automatically into the car by some vacuum mechanism. Might that be my problem? Because the exhaust ends at the rear axle which is basically below the rear seat and thus exhaust gasses can be drawn inside due to a vacuum? If I cannot solve this smell issue there is definitely not going to be any USA road trip for me :-). I was told to put a filter into the oil filler tube to avoid the oil aerosols hitting the engine and heating up = maybe causing the smell. I tried it, but is does not seem to solve the problem. Any suggestions? Lucas

08-03-2015, 05:53 PM	#2
RandyinUtah Senior Member Join Date: May 2010 Location: Ogden Utah Posts: 242	Re: Exhaust smell in car during driving This might seem off the wall but I have seen when a mouse moved in to muffler and made a nest or died. It took some time to burn the smell out of the exhaust system. Just a thought.

08-03-2015, 05:56 PM	#3
700rpm Senior Member Join Date: May 2010 Location: Portland, Oregon Posts: 5,902	Re: Exhaust smell in car during driving It might be your sealant burning off. It might be your manifold gaskets are not fitted properly. Unless you put on a brand new exhaust manifold, it might be warped and not sealing properly. It might be blow-by from the crankcase escaping out the oil filler tube. There is a special cap made with a hose that redirects those fumes out below the car (see Bratton's or Snyder's web sites). That's about the best I can suggest from 10,000 miles away. It is unlikely being sucked in from the exhaust pipe itself. __________________ Ray Horton, Portland, OR As you go through life, keep your eye on the donut, not the hole.

08-03-2015, 06:01 PM	#4
Brentwood Bob Senior Member Join Date: May 2010 Location: brentwood, ca Posts: 4,234	Re: Exhaust smell in car during driving exhaust pipe should extend about a foot past the bottom of the curve over the rear axle. Could also be curing out of the copious sealant, or if you repainted the intake and exhaust or the muffler assembly. No weeping at the steering column attachment to the gas tank, or the shutoff under the tank, or the fittings to the sediment bowl?

08-03-2015, 06:14 PM	#5
Mitch//pa BANNED Join Date: May 2010 Location: Bucks County, PA Posts: 11,454	Re: Exhaust smell in car during driving do you hear an exhaust leak??? it should be very easy to detect

08-03-2015, 09:26 PM	#6
My1930ModelA Member Join Date: Feb 2015 Location: New Philadelphia, Ohio Posts: 32	Re: Exhaust smell in car during driving Sponsored Links (Register now to hide all advertisements) Could be crankcase vapors from the oil filler breather. I also own a 1958 car and the crankcase fumes from this pre-PCV valve and other emission controls car are really strong. Just how it was back in the day.

08-03-2015, 09:28 PM	#7
My1930ModelA Member Join Date: Feb 2015 Location: New Philadelphia, Ohio Posts: 32	Re: Exhaust smell in car during driving Model A's also dont have a road draft tube to draw out blow-by crankcase fumes. They just spew out of the oil filler cap.

08-03-2015, 10:09 PM	#8
fiddlybits Senior Member Join Date: Jan 2014 Location: N Illinois Posts: 447	Re: Exhaust smell in car during driving Floorboards are heating up. Problem area most likely by carb / exhaust. I attached an aluminum panel with screws, using some nuts for standoffs, to the underside of the floorboards and my 'hot smell' went away.

08-04-2015, 02:59 AM	#10
H. L. Chauvin Senior Member Join Date: May 2010 Posts: 4,179	Re: Exhaust smell in car during driving FWIW: Always difficult to solve from miles away .... all above replies very possible causes. With windshield open, and "if" your gas tank cap is loose, rising gasoline evaporation vapors in hot weather could enter through the open windshield while traveling ........ or when stopped with engine fan blowing air out of sides of hood ..... mix this with engine blow-by out of the oil filler cap and you may have a "recipe" for a "mixed" odor.