Oil Mist in Car!!

[chiplynch]

Ok Guys..I have a '76 3.0 Carrera (Euro). The car has a 3.2 engine with PMO carbs and early style heater boxes. I have been noticing that the cars interior glass surfaces are oily after running the car. Ok I changed the oil thermostat O rings, the oil pressure sender (idiot light) and the base gasket as there was some oil there after running the car at DE events..but the problem still exists..Has anyone had this problem before? I know that it is not coming in through the rear firewall but rather through the ventilation system...

Please help! My wife always knows I've been driving the car..when I smell like Castrol 20-50w!!

philliplynch@charter.net

[willtel]

Have you checked the crankcase vent hose?

[snbush67]

Chip,

Have you considered the possibility that the residue on the windows may be from your interior vinyl off gassing? This is common in our cars. If it is oil coming through the ventilation then it would have to enter the heater tubes coming of the heat exchangers from the engine, doubtful.

Shane

[ossiblue]

Like Shane, my first thought was vinyl off-gassing which leaves a residue on the glass and is very common. What threw me was your comment on smelling like Castrol after a drive. Unless that comment was hyperbole, then you likely do have an oil leak somewhere. Any oil vapors in the engine compartment can be drawn into the heating circuit by the fan. See if you can nail down if the oil smell is entering through the heating ducts--that's critical and it's the most likely entry point. Give your entire engine the once-over for oil leaks and report back what you find.

[CCM911]

Have you checked the hoses which duct the heat up from the Heat Exchangers?

[chiplynch]

Well I was not aware of the Vinyl off Gassing issue. that would make sense excpet for the oil smell. The crankcase vent hose is secure to the oil tank and the heater hoses from the
fan are secure to the SSI heater boxes. What about the oil cooler seals?? These have not been changed..could it be leaking and somehow getting into the heater system??

[911pcars]

An oil leak. Gravity takes it into the heat exchanger(s). Check the obvious (valve cover, oil pressure switch, cam line).

Sherwood

[BoxsterGT]

+1 on oil leak dripping onto heater boxes with vapors being drawn up into car & onto windshield when De-foggers (or should I say Foggers) are on.

Len

[fbarrett]

Back in the old daze, an oil smell in a 911 was considered perfectly normal. We blamed the window fogging on the vinyl (and ArmorAll). My '70 E went over 175,000 miles on the original heat exchangers and muffler--because Porsche designed them to be protected by escaping engine oil!

Frank

[snbush67]

Maybe it's a combination of off gassing and oil residue.

I just don't understand how oil can get into the heat exchangers unless his heater hoses aren't hooked up and clamped.

My SSI's are open and all the oil that drips on them burns off at the stop lights that I occasionally stop at, depending on traffic.

Shane

[willtel]

Chip, I was actually referring to the other end of the crankcase vent hose. I used to have a similar issue on my car and after I fixed the separated hose it stopped.

Mine was like this:
Step on the throttle=windage increases=oily mist escapes from separated hose=oil smell in the cabin with the heat on.

Here is a picture of my failed hose.

[aj88cab]

Originally Posted by snbush67

I just don't understand how oil can get into the heat exchangers unless his heater hoses aren't hooked up and clamped.

The heat exchager joints around the exhaust pipes develop gaps as the HE ages. Oil can get inside the HE at those gaps. If the car has an engine blower fan, oil smoke can be drawn in thru there also.

[JeremyD]

The real problem here is that you smell like Castrol 20w50. You need to smell like Brad Penn 20w50. (unless you are going for the pitted cam, yellow brown stained case, worn components thing)

You have a leak - either one that's making it's way into the heat exchangers - Or one that's being sucked through the fan from the engine top - does your engine fan have oil residue on it? May be the crankshaft bearing at the front of the engine bay.

[snbush67]

Andrew and Jeremy, I get it now thanks. I wasn't considering the oil getting sucked through the fan.

[teenerted1]

it is the natural defogger results of driving an air cooled porsche in the winter...come on we all know water and oil dont mix

[lyonsfin]

I have an oil leak and when the car is still warming up, I arrive at stop light in a cloud of oil smoke from the oil dripping on the exhaust. It goes away a bit after the engine is warm, but with the heat on the oil smoke smell enters the cabin (I have the automatic heating so it's just the smell and NO heat!). IOt sounds like a similar problem and I think once the leak is stopped, the smell will also.

josh

[ossiblue]

Originally Posted by lyonsfin

I have an oil leak and when the car is still warming up, I arrive at stop light in a cloud of oil smoke from the oil dripping on the exhaust. It goes away a bit after the engine is warm, but with the heat on the oil smoke smell enters the cabin (I have the automatic heating so it's just the smell and NO heat!). IOt sounds like a similar problem and I think once the leak is stopped, the smell will also.

josh

We must remember that all warm air for the 911 comes from the "fresh" air circulating in the engine compartment--the majority of which is drawn in by the alternator fan, but supplemented in later cars by the engine compartment booster fan. It stands to reason that any smoke or vapors present in the engine compartment will flow into the heat exchangers and if the flappers are opened, into the cabin. The situation is amplified if there is leaking or poorly connected ducting to and from the exchangers.

[chiplynch]

Well guys, My engine cooling fan does have an oil mist on it so it must be sucking it in and then blowing it through the HE...I guess it could be the front main bearing seal? But wouldn't this also leak when the engine was turned off?

Your thoughts?

[snbush67]

How are you venting your oil overflow, to your carbs? If not you may want to consider fabricating an oil catch can and filter system. One of a million possible solutions.

Shane

[jlex]

Also, don't forget about possible a/c compressor leakage near the clutch. Look at the inside of your engine lid above the compressor. If you see a line of oil there, your compressor has been slinging fluid. Can easily be aspirated by the air intakes.