Exhaust fumes in cabin with heater running?

mthomas58 · 02-21-2009, 04:59 AM

This is my first winter since removing my cat. Exhaust fumes are significantly more noxious without the cat particularly with my high oil consuption.

Is it normal to smell exhaust in the cabin or have I got something wrong. Intense smell at idle/ stop n go traffic and not so much at speed with good air flow. Heater and flapper boxes appear to be functioning properly.

Any suggestions?

tonythetarga · 02-21-2009, 05:28 AM

It is not normal to have exhaust in the car from the HE. Are you sure it is exhaust and not oil smell? If it is exhaust then you have a hole in the exhaust or a leak into the heat exchanger which is blowing it into the cabin. It could be an oil smell which is caused by oil getting into the heat exchanger and that does happen from a leak above the HE.

mthomas58 · 02-21-2009, 05:49 AM

Quote:

Originally Posted by tonythetarga

It is not normal to have exhaust in the car from the HE. Are you sure it is exhaust and not oil smell? If it is exhaust then you have a hole in the exhaust or a leak into the heat exchanger which is blowing it into the cabin. It could be an oil smell which is caused by oil getting into the heat exchanger and that does happen from a leak above the HE.

It is not a burning oil smell. Definatley exhaust gasses and no oil leaks (knock on wood).

mthomas58 · 02-21-2009, 05:51 AM

Could I be sucking in fumes from the engine compartment up through the heater flapper boxes?

cgarr · cgarr's Garage

Quote:

Originally Posted by mthomas58

Could I be sucking in fumes from the engine compartment up through the heater flapper boxes?

This is what I have found most times, it is very important to make sure your seal in the engine compartment is sealed. This is one good thing about these cars, by sucking the air from the engine compartment you can tell as soon as something is wrong, I once had a generator short out and could smell something was not right.

ossiblue · 02-21-2009, 07:39 AM

As others have said, exhaust smell is not normal. Most likely you have an exhaust leak at the muffler/HE gaskets that is sucked into the engine compartment by the fan. Many cars do not have the seals in place, or they are cracked, warped and poorly seated. You may have a damaged HE, though that is less likely than a gasket leak somewhere.
Simple test is to briefly cover the tail pipe while the car is idling and see if you can hear the leak. This is definitely something you need to correct before using the heater again.

mthomas58 · 02-21-2009, 10:03 AM

Quote:

Originally Posted by ossiblue

As others have said, exhaust smell is not normal. Most likely you have an exhaust leak at the muffler/HE gaskets that is sucked into the engine compartment by the fan. Many cars do not have the seals in place, or they are cracked, warped and poorly seated. You may have a damaged HE, though that is less likely than a gasket leak somewhere.
Simple test is to briefly cover the tail pipe while the car is idling and see if you can hear the leak. This is definitely something you need to correct before using the heater again.

I would think the rubber seal around the engine tin is a more likely candidate in my case as I have all new muffler & HE gaskets having recently installed a cat bypass, but I will check these as well.