Smoke after long drive / Fumes in cabin

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joefarmer
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Smoke after long drive / Fumes in cabin

Post by joefarmer »

I believe I have an oil leak somewhere under the turkey roaster, but not 100% certain. Here is what I am seeing; any input is appreciated! Rebuilt 110hp with PG.

This weekend I got the dwell angle to 31 degrees, timing set to spec, carbs tuned to the best of ability. Took the car out for a 10 minute drive and all was good except that I smelled fumes in the cabin. Got back to the driveway, parked with the engine running, and opened the hood to take a look. Everything looked to be alright, but the strong fume smell was still there. I killed the ignition, came back to the engine, and noticed that a clear / white smoke was coming up around the fan and pluming out of the turkey roaster. I suppose while the fan was running it was pushing all of this smoke down and through.

I'm guessing I have an oil leak somewhere, but my question in on the best way to locate it. I'm planning to take the turkey roaster off and then reinstall carbs and linkage. Then run the engine for a few minutes and see if I can spot any oil leaking. Will I do any damage running the engine without the turkey roaster for just a little while?

Any other ideas?
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terribleted
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Re: Smoke after long drive / Fumes in cabin

Post by terribleted »

Start by removing the thermostat shrouds and inspecting for oil. The engine and shrouding should be clean , dry, and free of oil. If you see nothing then run the engine with the lower shroud still removed and see if anything becomes apparent. Common causes would be pushrod tube seals, valve cover gaskets or perhaps a top block cover (you will not be able to see the top block cover from the bottom but if it is leaking you should see oil film above the level of the pushrod tubes). If the engine was just rebuilt there should not be oil leakage unless something was assembled incorrectly, part mating surfaces not true, bolts holding gasketed items together not properly tightened come to mind.
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66vairguy
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Re: Smoke after long drive / Fumes in cabin

Post by 66vairguy »

What Ted said. If you don't see any oil leaks then there is the possibility that some critter has built a nest on top of the cylinders. It happens when cars sit for awhile. Of course that requires removing the carbs and top shroud to inspect.

Also if the "fume" smell is gasoline then a bad carburetor could be dribbling fuel onto the manifold. I've seen that once, amazed the car didn't catch fire.

The top engine cover (holds fan bearing) original bolts do come loose causing an oil leak. Some use serrated bolts, but they "chew" up the aluminum every time they are removed. I went to bolts with flat AND lock washers to fix the problem.
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bbodie52
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Re: Smoke after long drive / Fumes in cabin

Post by bbodie52 »

Attached is a copy of the Chevrolet service bulletin dated March 1971 that addresses Corvair Engine Fume Odor Diagnosis. It may be of some help to you.

:chevy:
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Corvair Maintenance - Engine Fume Odor Diagnosis.pdf
Corvair Maintenance - Engine Fume Odor Diagnosis
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Brad Bodie
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lalkie
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Re: Smoke after long drive / Fumes in cabin

Post by lalkie »

Check the PCV system to insure the small hole is not plugged. If plugged it can cause pressure in the crank case causing a leak. The fumes will enter the cabin thru the heater. Larry
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Re: Smoke after long drive / Fumes in cabin

Post by 66vairguy »

lalkie wrote: Mon Jan 22, 2018 4:28 pm Check the PCV system to insure the small hole is not plugged. If plugged it can cause pressure in the crank case causing a leak. The fumes will enter the cabin thru the heater. Larry
Good point - A buddy drove over one day for help finding the source of a "whistling sound". He shut off the engine and it kept whistling!! I turned the oil filler cap and it blew off into the air (I figured it would and was out of the way). The engine had a lot of blow by and a plugged PCV so the crankcase was pressurized and leaking fumes out every seal, hence the whistling sound. Needless to say the engine was covered in oil.
64powerglide
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Re: Smoke after long drive / Fumes in cabin

Post by 64powerglide »

My 64 was doing the same thing, top cover of the engine block had all new gaskets when I replaced the fan bearing but it was leaking down onto the cylinders. The torque specs are something 7 to 13 Ft. Lbs. I used lock washers & re-torqued it but I went to 16 Lbs,started them at 10 then went to 12 then to 14 then 16. I'm still getting some oil smell through the heater but it's getting better every time I drive it. Takes a while to burn it off & I even used engine cleaner before I put it back together. Check the PCV tube on the cover too, I put a new viton O-ring on that even though it was dry & not leaking.
Good luck. :tu:
64Powerglide, Jeff Phillips

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terribleted
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Re: Smoke after long drive / Fumes in cabin

Post by terribleted »

66vairguy wrote: Mon Jan 22, 2018 8:19 pm
lalkie wrote: Mon Jan 22, 2018 4:28 pm Check the PCV system to insure the small hole is not plugged. If plugged it can cause pressure in the crank case causing a leak. The fumes will enter the cabin thru the heater. Larry
Good point - A buddy drove over one day for help finding the source of a "whistling sound". He shut off the engine and it kept whistling!! I turned the oil filler cap and it blew off into the air (I figured it would and was out of the way). The engine had a lot of blow by and a plugged PCV so the crankcase was pressurized and leaking fumes out every seal, hence the whistling sound. Needless to say the engine was covered in oil.
A 64 Corvair should not have a PCV orifice, but a PCV valve. If the engine is later than 64 and has a orifice it should be clear. If the engine is set up with the normal 64 system, the PCV valve should be verified functional and the hoses to and from it clear.
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
Currently working full time repairing Corvairs and restoring old cars.
https://www.facebook.com/tedsautorestoration/

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66vairguy
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Re: Smoke after long drive / Fumes in cabin

Post by 66vairguy »

Good point Ted, but after all this time I've found all three types plugged up - open draft tube, PCV valve and orifice types. Usually with tired engines in poorly maintained vehicles.
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terribleted
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Re: Smoke after long drive / Fumes in cabin

Post by terribleted »

66vairguy wrote: Tue Jan 23, 2018 10:53 am Good point Ted, but after all this time I've found all three types plugged up - open draft tube, PCV valve and orifice types. Usually with tired engines in poorly maintained vehicles.
Certainly true, so have I.
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
Currently working full time repairing Corvairs and restoring old cars.
https://www.facebook.com/tedsautorestoration/

Located in Snellville, Georgia
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