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Oily mess!
Posted by: Peeeot ()
Date: September 22, 2019 07:01PM

I drive my '63 regularly, usually with at least 20 minutes sustained driving at 60-70 mph as well as plenty of stop-and-go. My engine compartment is clean, I have no external oil leaks, and I peek under the hood at least once very day I drive.

Today, after a normal trip, I pop the hood to find oil everywhere! Spattered on the underside of the hood, spattered on the firewall and spare tire compartment, some accumulated around the right carburetor, some accumulated inside of and underneath the right air cleaner assembly. It seemed to be focused around the dipstick. The oil fill cap area had comparatively little oiliness and the left side of the engine compartment was almost completely clean.

This look like the result of crankcase pressurization to me, so I checked the PCV valve. It is old, but the inner part moves freely and it seems to do what it ought to when I sucked on it or tried to blow backward through it. The passage from the crankcase vent tube to the right air cleaner assembly was clear.

Any thoughts as to what has gone wrong here?

1963 convertible - 102hp - 4-spd - 3.27 posi - central NC

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Re: Oily mess!
Posted by: Wagon Master ()
Date: September 22, 2019 07:17PM

What was your oil level on the dipstick when you checked it? Fuel in the oil?

'29 Ford Model A Tudor
'61 700 Lakewood 110 4 speed
'69 Monza Convert. 140 Auto.
'70 Dodge Challenger R/T 440 4 speed

Been aircooled since 1973
Northwest Ohio

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Re: Oily mess!
Posted by: MattNall ()
Date: September 22, 2019 07:44PM

Wash it down and check your Oil pressure switch.....also the gasket under the Gen / Alt mount...

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Oily mess!
Posted by: Peeeot ()
Date: September 22, 2019 07:51PM

Oil level was between the add and full marks, closer to add than full. Oil felt viscous and did not smell gassy.

The area local to the oil pressure switch and generator mount had minimal oil. The boot around the dipstick was oily and there was oil on the ignition wires and fan shroud around the dipstick.

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Re: Oily mess!
Posted by: MattNall ()
Date: September 22, 2019 09:00PM

You may have broken a piston ring.... pull all 6 plugs and look for an oily one..

Then do a LEAK test.... simple low pressure air 30 psi. Each piston at TDC

note 3 pistons are at TDC with each revolution of the crank pulley.. at 0 deg.

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Oily mess!
Posted by: JimBrandberg ()
Date: September 23, 2019 05:25AM

How about the oil filter?

A lot of oil everywhere sounds like oil supply under pressure rather than crankcase blow-by pressure. I could be wrong.

If you clean it up and do some testing you can narrow it down. I like using blue paper towels with paint thinner, the slow process is therapeutic. I'm not much for spray degreaser and lots of water anymore.

Jim Brandberg
Isanti, MN
CorvairRepair.com



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Re: Oily mess!
Posted by: Wagon Master ()
Date: September 23, 2019 06:57AM

JimBrandberg Wrote:
-------------------------------------------------------
A lot of oil everywhere sounds like oil supply under pressure rather than crankcase blow-by pressure. I could be wrong.

I would agree except if it's a pressure side leak it would have went until the level was below the pump pick up. If out the dipstick it slows down/stops when below the dipstick tube.

'29 Ford Model A Tudor
'61 700 Lakewood 110 4 speed
'69 Monza Convert. 140 Auto.
'70 Dodge Challenger R/T 440 4 speed

Been aircooled since 1973
Northwest Ohio

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Re: Oily mess!
Posted by: Peeeot ()
Date: September 23, 2019 07:04AM

I wiped everything down last night as a preliminary clean. I think it’s blowby because of the oil inside the right air cleaner, where the crankcase vent is, and the oil concentration near the dipstick. The total volume of oil spread throughout the compartment was pretty low, like maybe 10-20 mL. There was a small spattering of oil on the side of the oil filter by the crank pulley too; with all the rotating components and air flow it seems like there’s ample opportunity to fling any leaking oil all around.

I hope it’s not a broken piston ring! My plan is to finish cleaning up today and start the car and see whether blowby is excessive and/or the pcv is keeping up. If everything checks out, I’ll do some light local driving and check again for any sign of a repeat incident. If it looks like trouble I’ll pull the plugs and see about checking leakdown.

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Re: Oily mess!
Posted by: JimBrandberg ()
Date: September 23, 2019 07:18AM

I did reread the original post to see the leak seems to be centered around the dipstick.

In my earlier reply I was thinking about a leak that gets flung about by the fan belt.

It seems odd that blow-by would come all of a sudden but I suppose a broken ring rather than worn out would explain that.

Cleaning up and watching, checking the spark plugs and doing a Compression Test followed by a Leakdown Test are good suggestions already made by others above.

When doing Leakdown Test the piston should be at the top when the spark plug fires so the valves are closed. I go by rotor position and it often has to be adjusted, a little off and the air pushes the piston down.

Sometimes the Compression Test and Leakdown Test will not show a bad ring as the other rings are still holding cylinder pressure fairly well.

You could just have the breather venting to atmosphere to test the PCV. Probably plug the vacuum side while doing this.

Jim Brandberg
Isanti, MN
CorvairRepair.com



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Re: Oily mess!
Posted by: Peeeot ()
Date: September 24, 2019 09:26AM

I haven’t had a chance to go out and drive yet, but I have run the engine some to check things. So far there is no sign of oil leakage or spray or excessive crankcase pressure at all. Starting from cold, as the engine starts to get some heat in it I see some crankcase gases begin to appear when looking in the oil fill tube. At hot idle, the crankcase vapors will emerge from the fill tube in small quantities and get sucked into the fan. If I plug the tube with my hand, there is no evident pressure buildup. I never see vapor leave the small hose that connects the crankcase vent tube to the right air cleaner.

If I disconnect the pcv valve, there is a definite increase in crankcase vapors as observed at the fill tube. Just to be sure it’s in ship-shape, I thoroughly cleaned the pcv valve by soaking in carb cleaner overnight. It appears to perform the same as before cleaning.

Based on these observations, I’m guessing that at higher engine speeds and loads when more blowby is generated, the pcv system may not be doing the best job keeping up resulting in a little pressure accumulation. Maybe when I come off a long highway stint and let off the gas suddenly, which would cause the manifold vacuum to spike and the pcv valve to nearly shut, there is a momentary crankcase pressure spike that resulted in a “burp” of oil-laden crankcase vapor out the dipstick tube. If this is the case, perhaps the oil level in the crankcase is a factor as well.

Does the oil level in a full crankcase reach the base of the dipstick tube?

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Re: Oily mess!
Posted by: Wagon Master ()
Date: September 24, 2019 09:33AM

Yes. Yes it does. That's why the later tubes had an 1/8" hole drilled in the side right as it exits the block in the crankcase. Also why some choose to cut off the tube there. Plus it's why I suggested maybe the spray stopped once it got 3/4 of a quart low.

'29 Ford Model A Tudor
'61 700 Lakewood 110 4 speed
'69 Monza Convert. 140 Auto.
'70 Dodge Challenger R/T 440 4 speed

Been aircooled since 1973
Northwest Ohio

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Re: Oily mess!
Posted by: Peeeot ()
Date: September 24, 2019 10:31AM

Interesting! I wouldn’t have expected that.

Did some web digging on oil coming out of dipstick tubes and found it’s not uncommon! I am now thinking my dipstick tube is over-Installed because I’m 95% sure the dipstick tip touches the oil pan when fully inserted.

Does anyone have a dimension for dipstick tube length from upper end to outside face of block?

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Re: Oily mess!
Posted by: American Mel ()
Date: September 24, 2019 08:34PM

I didn't think it could be "over-installed".
Isn't there a small ring on it, similar to the Turbo pressure retard can?

-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
WA. state, 1 mile south of the Canadian border,
I am not at the end of the world, but you can see it from here.
Have; '66 Monza Coupe - 140, 4-spd. Daily driver beater
'67 Monza Vert. - 140, 4-spd. Daily driver beater
'67 A/C Moredoor Monza
Have had; '61 Monza coupe, '62 Monza Wagon, '63 Spyder, '65 Corsa
.
non-vair
'04 Dodge Cummins Quad Dualy, approaching 400K
17'Terry

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Re: Oily mess!
Posted by: MattNall ()
Date: September 24, 2019 08:47PM

Correct Mel.... but could be just plain tubing bought from a store!

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Oily mess!
Posted by: corventure Dave ()
Date: September 25, 2019 07:48AM

One place that can cause crankcase pressure is the PCV elbow that goes into the engine top cover. Depending on how many miles - years, this elbow can be obstructed with gunk from oil and crankcase moisture buildup from short trip driving. I have had to clear this elbow and the other crankcase tube on several peoples Corvair's over the decades.
Also, with the engine idling, crankcase vent system installed, remove the dipstick, wet your thumb, "spit" and place thumb over the dipstick fill tube. Raise your thumb enough to see if there is any pressure coming out to the crankcase. Call it spit bubbles!
Any crankcase pressure at idle will only increase at running speed.

Another quick and easy test. Take a folded paper towel and push the dipstick through it. Install the dipstick with towel back into the engine. Go for a test ride. Then see how much oil has come up out of the dipstick. This will give an idea of crankcase pressure.

Finally, the dipstick tube can be extracted and drilled above the oil line if it was not done factory.

Just some tips to try!

Corventure Dave

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Re: Oily mess!
Posted by: Wagon Master ()
Date: September 25, 2019 07:51AM

The overall length of the tube that sticks out of the block is 10 7/8".

'29 Ford Model A Tudor
'61 700 Lakewood 110 4 speed
'69 Monza Convert. 140 Auto.
'70 Dodge Challenger R/T 440 4 speed

Been aircooled since 1973
Northwest Ohio

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Re: Oily mess! Dipstick tube length
Posted by: MattNall ()
Date: September 25, 2019 08:20AM

Great info!

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Oily mess!
Posted by: Peeeot ()
Date: September 25, 2019 08:46AM

Thanks for the info, it is very useful! I will check the dipstick tube length.

I drove the car around locally last night and to work this morning, including cruising at an indicated 70-75 mph. No oil spattering at all! Everything seems normal and dry. I must have created a special situation to cause the mess that one time. Perhaps it was sustaining speeds at an indicated 80 for longer than I usually do.

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Re: Oily mess!
Posted by: MattNall ()
Date: September 25, 2019 10:31AM

Oil level was probably too high...

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Oily mess!
Posted by: Peeeot ()
Date: September 25, 2019 02:36PM

I checked and my dipstick tube is 10 7/8" from tip to block, so no problem there. My dipstick is 12 1/8" from full mark to the "cap" so that seems right also. Oil level was never above full.

A whole day of driving with no trouble at all. I guess I'll just call it a fluke and move on! Thanks for the help and suggestions!

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