Gunked up oil

[Akinon93]

Hello everyone, so the other day my grandpa and i decided to take the plunge and remove the oil pan on my 67 corvair...it is the worst i could have imagined it, with me being able to literally hold chunky mucky bits of oil in my hands. I was trying to clean the area with some parts cleaner fluid and a scrub brush but its REALLY on there. Im going to use some different tools to try and scrape some of the worst bits off, but does anyone have any advice on getting rid of the rest? Some kind of solvent maybe? Should i put seafoam motor treatment in with my next oil change?

[notched]

I have used cans of brake clean in the past to clean up some bad engines. You can use a putty knife or gasket scraper to scrape it out of the pan. The inside of the block you can try a combination of scraper and stiff bristle brushes. If it looks that bad there it will probably look just as bad under the valve covers.

[spyderman64]

If you find a thick gray residue in the bottom of the pan it's probably lead from the gasoline of 50 years ago. it's normal, but wear gloves when removing it.

[azdave]

Remove what you can get to mechanically and then if you're worried about what you can't get to then Auto RX is highly recommended. It's an oil additive that you use over a period of time to de-gunk a running engine. Forum member Richard1 is a very respected oil expert and he recommends AutoRX for engines that need a good internal cleaning. He posts more on corvaircenter under the same screen name.

http://www.auto-rx.com/

[Akinon93]

Thanks for the info guys, ill definitely have a look at the autorx because i have no idea how long the oil has been in the vehicle. At least 5 years as its been sitting in our garage not running, and it was black then when we checked it so i definitely want to try and clea out the parts im not able to get to as best i can.

[bbodie52]

The buildup of heavy materials at the bottom of the oil pan can occur over decades of engine operation. This sludge often fails to be carried out of the oil pan when the oil is drained,
so the heavy deposits continue to settle and remain there until the oil pan is removed and cleaned. The deposits can consist of lead contamination from leaded fuels that were in use during the early life of the Corvair. Sludge buildup caused by inadequate crankcase ventilation (road draft tubes in use from 1960-1962) and clogged or bypassed/modified PCV systems coupled with infrequent oil changes can also contribute to the sludge buildup. Short periods of vehicle operation when the engine never really warms up to full operating temperature can add to the mess. And engine wear and deterioration of bearings, gears, etc. can add a metallic flavor to the mix.

Here are some pictures of oil pan sludge from the Corvair Forum archives...

A lot of what you see in the photo is old lead deposits from leaded gas.

The first refinement in crankcase ventilation was the road draft tube, which is a pipe running from a high location contiguous to the crankcase (such as the side of the engine block, or the valve cover on an overhead valve engine) down to an open end facing down and located in the vehicle's slipstream. When the vehicle is moving, airflow across the open end of the tube creates a draft that pulls gases out of the crankcase. The high location of the engine end of the pipe minimizes liquid oil loss. An air inlet path to the crankcase, called the breather and often incorporated into the oil filler cap, meant that when a draft was generated at the tube, fresh air swept through the crankcase to clear out the blow-by gases.

The road draft tube, though simple, has shortcomings: it does not function when the vehicle is moving too slowly to create a draft, so postal and other slow-moving delivery vehicles tended to suffer rapid buildup of engine sludge due to poor crankcase ventilation. And non-road vehicles such as boats never generated a draft on the tube, no matter how fast they were going. The draft tube discharged the crankcase gases, composed largely of unburnt hydrocarbons, directly into the air. This created pollution as well as objectionable odors. Moreover, the draft tube could become clogged with snow or ice, in which case crankcase pressure would build and cause oil leaks and gasket failure.

Positive crankcase ventilation was first installed on a widespread basis by law on all new 1961-model cars first sold in California. The following year, New York required it. By 1964, most new cars sold in the U.S. were so equipped by voluntary industry action so as not to have to make multiple state-specific versions of vehicles. PCV quickly became standard equipment on all vehicles worldwide because of its benefits not only in emissions reduction but also in engine internal cleanliness and oil lifespan.

https://en.wikipedia.org/wiki/Crankcase ... ion_system

[Akinon93]

I been doing a bit of cleaning and thought id post here so other members can see the horror! Might have to just do the whole "change oil every time it gets dirty" thing since the oil i use has those cleaning additives. I do have a lot of old (unused) oil filters i can use during the cleaning process.

[BobWitt]

On your web site, you comment that it may have gotten hot or over heated... What you are doing to clean out the pan is good, but, with it being parked for this period, I'd suggest you take the upper fan shroud off and assure the fins are not clogged. Do this after you close up the pan, but before you drive any more!

Those broken heater hoses possible, but may not be the cause of an overheat...

You could have some rodent nests restricting your air flow, like the following photo posted by Brad!



Good luck with your project!

[Akinon93]

that's a good point BobWitt, thanks for the tip. We may end up doing that as well. The pan is closed up and the oil work is done for now, except the plug and putting oil in. It's definitely going to be ready for some long drives come spring time!