Toilet Flushing Issues

[Dozer]

Since I have lived in this mobile home(2yrs) there has been an issue with the toilet plumbing. Its a 1985 Skyline. I put in a new toilet when I moved in.
If you flush the toilet, 90% of the time it will fill up, and not go down. This is even if no toilet paper is in the bowl. Even if its just fluids. It will slowly trickle down.
Sometimes, it will fill up more than normal. I will hear a bubbling sound in the walls, and beneath the floor. And next thing you know, the water will just, Swoosh!, go down really fast.

I checked the upper vents, cleaned them, there was bird nesting material in there, cleaned all the ones in the roof with a long metal rod, while running water down them. Then followed with continually running water down them. They did not fill up with water, water kept going.
Though maybe it needs a higher flow of water to cause it to back up into the vent.

Anyway. I'm sure that its all related. I still need to get under there and check the angle of the piping that goes from the toilet. Never did that. I do remember seeing some metal scraping on both sides of the pipe, as though they were connected to support the pipe. But to be honest, I was under there for a different reason, and never really looked at it, so I will do that tomorrow..

Any thoughts???
Thanks..

[Greg]

It does sound to me like a vent problem, somewhere. If you checked the roof vents and everything is clear, I would take a look and see if you have any under the counter (check valve type) vents. They should not be tied into the toilets but you never know. Next I would go outside and check for a vent on the tank (or system) side. If you have a venting problem after the pipe goes into the ground the system could be holding a slight pressure and not allowing anything in until it vents all the way back through the system out the roof vent.

A quick way to check would be to pull the pipe out of the ground connection and see what happens when you flush water down the toilet. If it flushes correctly the house side is working and it has to be in the ground side. You will have a few gallons of water under you home unless you use a bucket to catch it, but it will tell you in a hurry where the problem is. Greg

[Lorne]

Could a rag have been left in the drain opening when the toilet was installed?
Like a rag left in an engine cylinder when putting the head on. That was a fiery start up.

[Greg S]

Do any of your sinks drain slowly or gurgle when they are draining. When you use the washing machine or dish washer do any sink drains gurgle. If any of these are happening you have a main drain issue or possibly a vent. If however none of these things happen your problem is most likely in the toilet drain itself.