My washing machine drain is backing up. The machine is about 4 or 5 years old and I live in a 57 year old house. Never had a problem until now. I've already had a plummer out that snaked the pipe (1 1/2 inches) 100 feet and he snaked the vent on the roof 100 feet but its still backing up. He even checked the trap for the house but that's clear. Nothing else in the house is backing up.

Now here is my question. Outside the house about where the washing machine is is a tiny pipe sticking out. It comes out of the house and it bent 90 degrees toward the ground. The original owner also used to like to do things on his own. A lot. Could this be the vent for this pipe? I can't see any of the plumping and I can't get to the crawl space. The plumber does not no what's wrong so he just wants to cut into the wall put in a L joint and run a new line to the sewer. That's a lot of money $1500 to be exact plus the cost to repair the wall and maybe even the stucco outside the house and cutting into the drive way. I just can't help but wonder if that little tiny pipe could be air vent and if blocked causing the back up.

Also just a note that when the water backs up and I stop the washer to let the water go down it is sucking air when it gets down to the drain.

I don't think this is a vent. Sounds more like a Water Heater T&P valve discharge pipe if it's copper or a AC condensate line or a pan drain if PVC.
[QUOTE][when the water backs up and I stop the washer to let the water go down it is sucking air when it gets down to the drain./QUOTE] NowTHAT sound like a blocked vent. If the plumber snaked from thje washer vroof vent he didn't put out enough cable, If not call him back to snake the roof vent.
If clearing the vent didn't help We have had quite a few complaints like yours, ( especially with new MayTag washers) where the washer pump is too powerful for a 1 1/2" trap and stand pipe.
I have a solution that I've never had a complaint on and one that I had to use on my washer. You close off the stand pipe the washer connects to with a compression fitting,(see image) or I caulked the hose in with rags and sealed it with duct tape. This makes a water tight connection between the washer and the stand piipe. Nothing can leak out or overflow and the force from the pump will send the discharge out into the main drain. While there is some back pressure involved there will not be enough to damage the washer pump. You aOutside of oversizing the washer trap and standpipe or reducing the opening at the end of the hose You may also install a "surge pipe" (see image) on the washer stand pipe. These are about the only solutions that I know that works. Good luck and thank you for rating my answer. Tom

Is the vent generally in close proximitey? I wonder if it would be worth the time and money to replace the vent (cutting through the wall of course). I am a little concerned with the strain on the water pump of the washer. If I do the patch route is it better to do smaller loads so the water doesn't have to be forced down for as long a period? If my thinking is correct that is.

In the hundreds of washer's that we have made a closed system, (I have one installed myself) there has never been a complaint about a pump that failed. This works!! I've had my 1 1/2" standpipe closed off for years with no problems and, most importantly, NO Backups!.
Good luck, Tom

My last question is this. Looking at the image you posted on the right my washer goes hose goes straight into the drain in the wall and not a pipe like that picture shows. Which fitting would work best? Also I live in Tampa and would be willing to hire you or someone recommended to close the system off since my current plumber never even thought about this.
Thanks!