gas in oil pan

[gregchrysler]

Hello everyone    anybody know what would cause  gas to be in the  oil pan.  The garage said the oil was 30 % gas. Do u think it could be an intake vale stuck or bent?  I ran an electric pump through the mechanical pump  could th gas get in through there?  Thanks everybody  car is a Chrysler royal woodie 1949  also for sale

[Janousek]

Mechanical pump diaphragm torn leaking gas into engine is about the only logical explanation.   Especially if the car runs OK.  

[gregchrysler]

thanks  car runs ok  wouldn't be from carb?

[Grimy]

Another possibility is overpressure from the electric pump dumping extra fuel into the manifold to a degree that the rings can't handle it.  What's the rated output of your electric pump in psi, and do you have a pressure regulator on it?  I think you should restrict the output from the pump/regulator to no more than 3 psi.  Don't use the $20 regulators in the bubble packs at chain stores.  A good one, like Holley, will be about $60.  Assuming that the oil has been changed, sniff the dipstick periodically for gasoline odor until you're certain you've fixed the problem. 

[JFranklin]

I saw an engine that blew up due to a similar problem so be careful.

[PFitz]

 You couldn't get 30% gas in the oil pan by way of past the rings and still have what anyone would call "a good running engine".

 

But an electric pump driving through a mechanical fuel pump that has a diaphragm leak will put that much gas into the oil pan.

 

BTW, no need for a regulator - just one more thing that can go wrong and possibly harm an engine.  Summit Racing has low pressure 6 volt pumps for about $45.00.

 

Paul

Edited December 14, 2017 by PFitz (see edit history)

[hchris]

Definitely passing through the mechanical pump Diaphragm; fuel in sump is a classic symptom of failed fuel pump diaphragm.

[Ben Bruce aka First Born]

I agree, Paul. If, in fact, that much gas in the oil pan . Been a long time since I was inside a Chrysler engine and I can think of no other way. Pull the fuel pump and inspect.

 

  Ben

[gregchrysler]

thanks everyone  will run electric pump around mechanical

 

 

[Bhigdog]

50 minutes ago, gregchrysler said:

thanks everyone  will run electric pump around mechanical

 

 

 

Or.........Replace the mechanical with a good one and use the electric only to prime the carb if the cars been sitting awhile or if you suspect vapor lock. The car was designed for a mechanical pump and will run fine with one. If it ain't broke don't fix it...................Bob

[Bloo]

For a carbureted car there is NO better, no safer, no more reliable solution than a mechanical fuel pump driven by the engine, a fuel filter (not plastic) at the carb, and a sock on the fuel pickup in the tank, IF you can make it work without vapor lock. There are a whole raft of good reasons it was done this way for 50 years.

 

Many on the forum have added a pump only for priming. That sounds like a reasonable solution if you need to do it due to an otherwise unsolvable vapor lock or dry start problem. I haven't had to do it to anything I currently own. I hope I don't have to.

 

 

 

 

[PFitz]

Whenever adding an electric fuel pump, if it's not the same pressure as the original mechanical pump, the  fuel pressure change  will also change the carb's float level.  The float level is more critical than most car owners realize. 

 

A properly rebuilt mechanical pump will last a life time and it is the correct fuel PSI for that carb.  

 

So, here's another vote for rebuild the mechanical and use the electric as a primer pump.

 

Paul

 

 

[dictator27]

13 hours ago, JFranklin said:

I saw an engine that blew up due to a similar problem so be careful.

Likewise.  An explosion in the oil pan caused by a leaking fuel pump blew both rocker covers off the engine.

[JACK M]

2 hours ago, dictator27 said:

Likewise.  An explosion in the oil pan caused by a leaking fuel pump blew both rocker covers off the engine.

Not to mention oil pan gaskets etc.

[ArticiferTom]

If diaphragm is leaking there will be gas leaking out bottom of pump also .  As there is a hole to atmosphere to permit pump functioning . Is it down draft carb , flooding ?

[old car fan]

You do not need a electric pump,Unless you are collecting insurance for a car fire.

[Rusty_OToole]

Just get the stock pump rebuilt and forget the electric. If you MUST have an electric pump wire it through a switch and use it sparingly, for easier starting and in case of vapor lock, do not use all the time.

[Marty Roth]

Fuel Pump Diaphragm allows fuel to pass into engine, settling in oil pan-

 

IT HAPPENED TO MY 1977 SUBURBAN -

NEXT MORNING IT EXPLODED, 7:00 AM on a Sunday

TORE OFF THE ROCKER COVERS AND OIL PAN

 

Neighbors thought I was doing business with the wrong people