Burning oil odor inside the cabin?!?!??!

[tonyankyfan1]

Greetings guys-

I have a burning oil odor inside the cabin whenever i put the heater ON, of my 98 mystique GS, zetec. What can be causing this?

Thanks Anthony

 

[RichR]

Check the valve cover gasket first..

 

[tonyankyfan1]

Check the valve cover gasket first..

Firstly--> Thanks for your reply.
Secondly, how would a leaky valve cover gasket affect the cabin air?? The valve cover gasket is brand new, Fel pro. But i do have a leaky oil pan gasket though.

Thanks, appreciate your help!
Anthony

 

[gmorrell]

Look for an oil leak that's dripping on a catalytic converter or some part of the exhaust, that's where the burning smell is coming from. These cars take cabin intake air at a vent in the cowl below the base of the windshield. Make sure the big gasket at the back edge of the hood is in place, as this keeps engine compartment air from getting into the cabin intake air.

 

[amc49]

X3. Like said check valve cover. usually the smell comes from top of motor but bad enough under and can do it when it wafts up back of motor too. The natural air flow there seeps up under back of hood to get pulled into the fresh air cabin duct.

Your new gasket may be leaking, many don't clean good enough and it happens.

 

[RichR]

Zetec valve cover gaskets are notorious for failure. Even when they are brand new they will leak. My advice is don't cheap out on a gasket set. Go with OEM or Felpro, Victor Rienz.

 

[tonyankyfan1]

Hey Guys-

Thanks so much for all the replies and help, I greatly appreciate it!!! I will check again tonight.....
It only happens and smells when the HEAT is ON, the odor.. It does'nt smell at all when the climate control is OFF. Is there anyway that i can shut or plug the fresh vent from entering into the cabin???

Thanks Anthony

 

[amc49]

Not really, it's where your hvac air comes from. There's a recycle door that pulls air in from inside the cockpit but it is closed on heat. In short you would have zero airflow from the dash in heat.

 

[gmorrell]

To be more specific, the only HVAC function that closes the outside air door is MAX A/C, which then recirculates cabin air to lessen the cooling load and cool the cabin more quickly. For all other HVAC functions, the outside air door is open.

If the Mystique is similar to the Contour, and it damn well should be, the plastic cowl at the base of the windshield should have some slots on the drivers' side, forward of the driver's wiper arm, this is the cabin fresh air intake. Air flows through these slots and under the cowl across to the passenger side where the cabin air filter and cabin air intake is located.

If you're getting engine compartment fumes into the cabin air intake, it is very likely that the large rubber gasket that seals the back of the hood is missing or damaged.

Random picture from the Intertubes. The gasket is clearly visible at the base of the Black plastic windshield cowling, just forward of the wiper arms, and stretches from side-to-side under hood. It needs to be there and be undamaged or under hood air will exit right over the cowling and you'll get to breathe it whenever you're using the cabin HVAC.

 

[tonyankyfan1]

To be more specific, the only HVAC function that closes the outside air door is MAX A/C, which then recirculates cabin air to lessen the cooling load and cool the cabin more quickly. For all other HVAC functions, the outside air door is open.

If the Mystique is similar to the Contour, and it damn well should be, the plastic cowl at the base of the windshield should have some slots on the drivers' side, forward of the driver's wiper arm, this is the cabin fresh air intake. Air flows through these slots and under the cowl across to the passenger side where the cabin air filter and cabin air intake is located.

If you're getting engine compartment fumes into the cabin air intake, it is very likely that the large rubber gasket that seals the back of the hood is missing or damaged.

Random picture from the Intertubes. The gasket is clearly visible at the base of the Black plastic windshield cowling, just forward of the wiper arms, and stretches from side-to-side under hood. It needs to be there and be undamaged or under hood air will exit right over the cowling and you'll get to breathe it whenever you're using the cabin HVAC.

GREAT EXPLANATION, THANKS. THE RUBBER INSULATION IS THERE AND IN GOOD SHAPE. IM STUMPED!!! MAYBE I NEED TO CHECK THE FIREWALL FOR ADDITIONAL HOLES ALLOWING ENGINE AIR INSIDE OF CABIN.

 

[tonyankyfan1]

GUys-

It ended up being a silver dollar sized hole in the driverside firewall that was made to run wires through for the alarm and such from the previous owners. A pretty big hole, it was actually under the brake booster on the drivers side. I duct taped the hole up and will see what happens next.

Thanks Anthony