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Smelling burnt oil in vents


cdictas

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Gentlemen,

I've been smelling the presences of burnt oil coming through my air vents in my 99 STS when my car is stopped. I took my car to the dealer this week to get the tranny fluid changed out and to see if they could identified the source of the oil smell. They told me my mid case was starting to leak and it would cost $2200 to reseal it. Needless to say, that's not happening. I took a look at the mid case sealing procedure that was posted on FAQ section, and I noticed that the exhaust manifold is above the mid case and seems to be out of the way of any oil dripping on it. I had hope the dealer was going to tell me I needed a new valve cover gasket.

Any thoughts from the group?

Chuck

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I dont know if this is an issue with your year but take a good look at your HVAC housing to make sure there are no cracks or breaks.. They are plastic and tend to crack. We discussed this recently, you may be sucking in fumes from the engine compartment.

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Can you consistently duplicate the burned oil smell? A/C on and off?, inside air recirculate?

Your HVAC outside air intake is at the base of the windshield in an area that should be closed off from underhood activity by a rubber seal at the top of the firewall. Maybe your seal is compromised?

The exhaust cross-over pipe from the left (or front) bank is below the case split.

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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From time-to-time I will also get a burning oil smell come in through the vents due to a leaking oil pan gasket dripping oil onto the left side exhaust pipe.

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Sounds like its time to go looking for oil leaks. There are several things other than the case half seal that can leak and cause oil to drip onto exhaust pipe that runs under the oil pan. In fact, its probably a better than even chance that your worst leak is from something other than the case-half. Search some old posts for oil leaks if you haven't already.

Good luck.

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JimD and Group,

I took a look at the rubber seal today at lunch, it appears to be intact (no tears, pliable). After work I'll armour-all the rubber and take a spin around the block.

The smell is reproducible at idle at any stop sign or light. I don't smell burnt oil when the A/C is running. I have not tried the recir setting yet.

The left side of the engine is the even numbered cylinders correct? If so, there is no oil dripping or leak from the left side. What I did notice several weeks ago was the black stiffener plate near the oil drain plug was wet with oil. I need to investigate this area again.

Chuck

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It can be tough to locate the exact source of drop or two of oil due to road draft, surface tension and other variables.

Sources of engine oil include the usual suspects like cam cover gasket, oil filter adapter O rings, oil pressure sender, crankshaft position sensor O rings, oil dipstick tube seal.

And don't overlook the possibility of a power steering pressure line leak.

The bottom end of my '98 stays wet and I just refer to it as the "external oiling system". The rear surface of my engine cradle will never develop rust.

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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