engine and drivetrain Exhaust fumes entering cabin from under dash/floor panel

[asifallasleep]

I just bought a beautiful 74 2002. Only issue is i can feel and smell the warm air/exhaust from engine entering cabin from floor/underneath dash. Does anyone know what the two holes are that are on each side of the shifting console? It's almost like both sides have cardboard bent out, leaving a hole. I'm thinking the fumes from the engine re entering through these two holes. Can i seal these holes up? I've looked at pictures of 2002's and they all seem to have this bent out cardboard on each side.

[billw]

I believe those holes are the heater vents. Mine blow warm all the time because my switch is stuck and I can't shut them off. No fumes from there tho. I did have fume smells in the cabin but they went away when I replaced the round foam piece underneath the shifter rod.

Bill

[asifallasleep]

Interesting. I'll have to check to see where my heater levers are if those holes are the heat vents as you say. I found an article (www.02restoration.com) that suggested fumes entering the cabin from the engine were caused by hose coming from the valve cover:

I started searching for a leaky muffler or hole in the trunk of the car which would have been leaking exhaust fumes into the interior.

Failing to find any holes, I turned to the engine compartment. It turned out that the rubber hose attached to the valve cover and which is normally connected at the other end to a PVC valve and carburetor (allowing the carburetor to re-burn the fumes accumulating under the valve cover) was no longer attached to a PVC valve (Sometimes this occurs if OEM carburetor was replaced).

In fact, it was laying across the top of the valve cover with it's open end pointing toward the radiator fan. The fumes coming out of the hose were therefore being directed by the fan right back into the engine (and passenger) compartment.

The solution - redirect the open end of the hose between the firewall and rear end of the engine (away from the radiator fan), and back towards the ground. An easy fix!

Author: Ron Bass

I'll have to check this in the morning. Fumes aren't in my trunk so i've ruled out the common issue with the gas tank needing to be resealed and the expansion tank ventilation tube being redirected.

[asifallasleep]

I believe those holes are the heater vents. Mine blow warm all the time because my switch is stuck and I can't shut them off. No fumes from there tho. I did have fume smells in the cabin but they went away when I replaced the round foam piece underneath the shifter rod.

Bill

where did you get the round foam piece underneath the shifter rod? do you have a part number?

thanks.

[billw]

realoem has it as part #23411200937. A quick check of Autohauz has them for about $14.00, you might try Blunt tho.

Bill

[asifallasleep]

oh wow awesome. thanks. i'll try that before i take it to the shop.

[Bimjam02]

11.99 at rmeuropean.com

[c.d.iesel]

. . . . . . "where did you get the round foam

piece underneath the shifter rod?

do you have a part number?

the pad goes between the shifter bracket

from UNDER the car. Take a bright light

down there and scope it out before you

buy any parts. Make a list of the other

stuff that's broken, missing, loose,

worn out. The shifter bracket has an adjustable

support arm with a bushing that's usually gone.

I promise your trans mount mount is toast.

Look at how the exhaust is supported by the rear

of the transmission(it should be) Important support

bracket with insulating bushings should be there......

you bought a BMW - That means you can go to any BMW

car dealer and order your parts and have them in a day

or two, and at prices no different than most vendors.

And most dealers offer you a BMWCCA club discount on parts.

No need to raid your mothers laundry room for a close pin

to hold your headlight tight. Parts are at the BMW store.

[c.d.iesel]

[Mike Self]

and those two outlets on the console are indeed heater outlets--the pieces of hardboard are deflectors so the warm air won't melt your socks while you're driving.

One or more of the seals around the heater plenum chamber (space under the windshield between firewall and engine room, below the hood louvers) is bad, missing or leaking. There are three seals: a long one that fastens to the hood, two short ones on either side (the hood latch rod passes through 'em) plus three drain hoses on the bottom of the plenum chamber. They're generally called "elephant trunks" or "duck lips" due to their shape. They're pinched together at the bottom to keep fumes out, but will allow accumulaing water to drain when it falls into the plenum chamber. My guess is the side seals and duck lips are rotted out.

Replace 'em or get sick from CO fumes in your passenger compartment. CO poisoning isn't anything to mess with. Ask me how I know!

cheers

mike

[Guest Anonymous]

It turned out that the rubber hose attached to the valve cover and which is normally connected at the other end to a PVC valve and carburetor (allowing the carburetor to re-burn the fumes accumulating under the valve cover) was no longer attached to a PVC valve (Sometimes this occurs if OEM carburetor was replaced).

Fumes aren't in my trunk so i've ruled out the common issue with the gas tank needing to be resealed and the expansion tank ventilation tube being redirected.

Crankcase gases are directed toward the intake system but there is no check "valve."

The smell of petrol is different than exhaust fumes.

If in doubt - windows and sunroof wide OPEN!

[asifallasleep]

and those two outlets on the console are indeed heater outlets--the pieces of hardboard are deflectors so the warm air won't melt your socks while you're driving.

One or more of the seals around the heater plenum chamber (space under the windshield between firewall and engine room, below the hood louvers) is bad, missing or leaking. There are three seals: a long one that fastens to the hood, two short ones on either side (the hood latch rod passes through 'em) plus three drain hoses on the bottom of the plenum chamber. They're generally called "elephant trunks" or "duck lips" due to their shape. They're pinched together at the bottom to keep fumes out, but will allow accumulaing water to drain when it falls into the plenum chamber. My guess is the side seals and duck lips are rotted out.

Replace 'em or get sick from CO fumes in your passenger compartment. CO poisoning isn't anything to mess with. Ask me how I know!

cheers

mike

wow thanks mike. i'm going to take the car the Jack Fahuna in the valley on thursday am. the car was restored by this guy with everything new in the car. it looks and drives amazing. only 3K on the new engine. great except for the exhaust fumes.

[asifallasleep]

It turned out that the rubber hose attached to the valve cover and which is normally connected at the other end to a PVC valve and carburetor (allowing the carburetor to re-burn the fumes accumulating under the valve cover) was no longer attached to a PVC valve (Sometimes this occurs if OEM carburetor was replaced).

Fumes aren't in my trunk so i've ruled out the common issue with the gas tank needing to be resealed and the expansion tank ventilation tube being redirected.

Crankcase gases are directed toward the intake system but there is no check "valve."

The smell of petrol is different than exhaust fumes.

If in doubt - windows and sunroof wide OPEN!

it's exhaust fumes and not petrol.

[asifallasleep]

. . . . . . "where did you get the round foam

piece underneath the shifter rod?

do you have a part number?

the pad goes between the shifter bracket

from UNDER the car. Take a bright light

down there and scope it out before you

buy any parts. Make a list of the other

stuff that's broken, missing, loose,

worn out. The shifter bracket has an adjustable

support arm with a bushing that's usually gone.

I promise your trans mount mount is toast.

Look at how the exhaust is supported by the rear

of the transmission(it should be) Important support

bracket with insulating bushings should be there......

you bought a BMW - That means you can go to any BMW

car dealer and order your parts and have them in a day

or two, and at prices no different than most vendors.

And most dealers offer you a BMWCCA club discount on parts.

No need to raid your mothers laundry room for a close pin

to hold your headlight tight. Parts are at the BMW store.

i've owned 4 bmw's (most recently a '05 Z4) and 3 porsche's (84 944, 2000 boxster, 2003 911) and a bunch of other cars. I like this 2002 better than the Z4 i sold. I was thinking it was something i could fix myself but yeah, taking it to the shop thursday am.

[asifallasleep]

Yesterday I noticed some moisture around the fuel sending unit. My suspicions were confirmed today when I filled up my tank and saw gas seeping out the tank into the trunk from around the fuel sending unit. Today I replaced the O ring around the fuel sending unit. I think that may have finally solved the fuel odor in the cabin.

Thanks for all your help everyone.