Lesson Learned

[RickBrinker]

I haven't started my 29 DeSoto in 2 1/2 years it started ok
let it run for about 15 min started smelling varnish engine quit
pulled carb full of varnish and the engine is now stuck with varnish
engine only has 2000 miles now i have to figure out what to do about
freeing the stuck engine

 

[nearchoclatetown]

That sucks, Rick. Are you using non ethanol gas? From what I have been reading it's probably the valves that are stuck.  I am not convinced paying the extra for no ethanol is worth it. It's been acting goofy for me. Not trying to start an internet rumor but I am not convinced any of it is any good. I was washing some parts a week ago with non ethanol and it was very humid and raining. The stuff clouded up and separated just like ethanol does. Normally I would recommend Berkebile 2+2 Gumcutter carb cleaner but was just told they went enviro. It is now in a green can and doesn't even burn or clean carbs. Is the chicken traveling you this weekend?

[RickBrinker]

Chicken will be there

[JFranklin]

1 hour ago, nearchoclatetown said:

That sucks, Rick. Are you using non ethanol gas? From what I have been reading it's probably the valves that are stuck.  I am not convinced paying the extra for no ethanol is worth it. It's been acting goofy for me. Not trying to start an internet rumor but I am not convinced any of it is any good. I was washing some parts a week ago with non ethanol and it was very humid and raining. The stuff clouded up and separated just like ethanol does. 

They maybe were selling ethanol gas mislabeled to make more profit. Real gas doesn't do that.

[idrjoe_sandiego]

Hey Rick:

Sorry to hear about your beautiful DeSoto. I love that car!

Help me understand your situation. Are you saying that you had not started the engine for 2.5 yrs, but when you recently tried to start it, it started up ok and ran for 15 minutes and you smelled varnish?   Then you cleaned the carb, but when you tried to restart it, suddenly the engine was seized?

 

If I am getting your story correct, no question, over time, unSTABILized modern fuel turns to varnish and will muck up the fuel tank, the carb, and anything in between.  The varnish usually is trapped in the fuel line, the carb or the fuel filter, preventing the engine from running very well or at all.

 

I just don't see how a running engine would seize because of the varnish. As Doug points out, it is possible the valves are affected, but if that were the case, the engine would have never run for 15 mins. IMHO something beyond varnish is to blame.

Edited August 4, 2021 by idrjoe_sandiego (see edit history)

[RickBrinker]

I looked in the one cylinder with a borescope and can see varnish on the walls when i get home on Monday i'll pull the side covers off i see if the vales are stuck

[idrjoe_sandiego]

So are you saying that the engine won't turn over with the starter motor or it wont turn over even when you hand crank it?

 

The first thing that comes to mind in this situation is the engine is hydro-locked.  Easy to figure out. Pull all the plugs and see if it will turn over with no compression resistance. If hydro-locking was the problem, usually the engine turns freely after the plugs are removed. Additionally fluid will shoot out from the affected cylinder(s) as you turn the engine over.

 

Another possibility is the engine is truly seized from lack of oil or water in the crankcase oil. What is/was the oil level and how does the oil look/smell? Does the oil look like chocolate milk?

Edited August 5, 2021 by idrjoe_sandiego (see edit history)

[Minibago]

Modern fuels degrade more quickly than before due to a combination of evaporation and oxidation changing the fuel properties altering the combustibility and leaving a sticky residue behind. (Note various components of the fuel evaporate at different rates) Normal shelf life of gasoline today is between three and six months. Temperature has an effect, if stored at 20 degrees C it will last approximately 3 months but at 30 degrees it could be as short as one month.

Adding ethanol to fuel increases the fuels ability to absorb moisture from the atmosphere, if the humidity is high fuels last even less time however the time does not start when you fill your tank but when it leaves the refinery process. A fuel stabiliser containing anti oxidants, corrosion inhibitors and metalde-activators is helpful for cars not used much.

A hotter spark plug will help with rough running.

Not sure how this has caused your engine to seize. Valves stuck should not cause this. 

 

[Kenendcindyc]

Yup it can happen, I had a small 12 HP engine I was using daily and it ran great. One day the wife took a gas can to get some gas and she took the wrong one. The one she took had a little very old gas in it that turned to a solid varnish at the bottom. The new gas kinda dissolved it and it mixed with the new gas. When running I could smell the old varnish, I didn’t  think much of it but after turning it off and letting it cool it was seized up solid. I was able to get it turning with some solvent in the cylinder and a big ratchet. Once free it ran fine but seized again after cooling. Flushed out fuel system and ran it a few hours and all was fine after that.