E70 X5 Keep getting P0442 Small Evapor Leak

[gregg3gs]

The issue I had was with a code P0456 - EVAP System - Very Small Leak Detected, but to me it seems the same as yours.

Things I would notice while experiencing the issue:
- smell of gas inside the car
- smell of gas outside of the car, about the back of it (especially on hot days and after tank got to half +/- a 1/4 tank)

I was able to fix it.
My fix included:
- replacing the gas cap (I don't think it was the problem)
- replacing the seal, clamp, top retaining "C" assambly clamp on the fuel tank pump under the passenger rear seat (I don't think this was a problem)
- pulling fuel pump up and after disconnecting the connector noticing one of the pins had melted plastic around it. I filled the hole with JB Weld and connected the electrical connector to hold the assembly together until jb weld dried. Obviouse repair would be to replace the fuel pump. (this was the apparent problem)

All in all I understand that the original firmware in the x5 sends too much current to the fuel pump and it keeps connector hot, melting plastic around it. I had new firmware loaded a year after I got the x5 (car was five years old at that time), but the damage was already done.

I did the repair about two months ago, all is good now.

[Skyline]

Originally Posted by gregg3gs

- pulling fuel pump up and after disconnecting the connector noticing one of the pins had melted plastic around it. I filled the hole with JB Weld and connected the electrical connector to hold the assembly together until jb weld dried. Obviouse repair would be to replace the fuel pump. (this was the apparent problem)

All in all I understand that the original firmware in the x5 sends too much current to the fuel pump and it keeps connector hot, melting plastic around it. I had new firmware loaded a year after I got the x5 (car was five years old at that time), but the damage was already done.

I did the repair about two months ago, all is good now.

What caused that connector to heat up is not too much current, it's either a slightly loose connection, or a little bit of corrosion. The current bridges the poor connection, in return, making little tinny sparks, and causing heat. Certainly not the best thing around the fuel pump. If the problem reoccurs, I would clean the contacts and pins very carefully on that connector, and use some good contact cleaner on it. I might want to use some dielectric grease on the connectors as well.

[gregg3gs]

Originally Posted by Skyline

What caused that connector to heat up is not too much current, it's either a slightly loose connection, or a little bit of corrosion. The current bridges the poor connection, in return, making little tinny sparks, and causing heat. Certainly not the best thing around the fuel pump. If the problem reoccurs, I would clean the contacts and pins very carefully on that connector, and use some good contact cleaner on it. I might want to use some dielectric grease on the connectors as well.

sounds about right....

[X5Cat]

All good stuff. I will be checking my electrical connections. A poor connection equals resistance. Current lost to resistance is dissipated primarily as heat. Too much heat in one place equals trouble.

[wetzie]

It would be great to follow this through to a fix. I am having the same code P0442 and is keeping the CEL on. The 2009 X5 3.0 is out of warranty and is sitting at 56K miles. It runs very well with no smells or hesitation. I purchased the BMWhat ap and reset the CEL and the X5 would run with no errors for several days. It starts with the check gas cap error and then later puts up the CEL a couple of days later.
I purchased a new gas cap and the problem came back quickly.
I then purchased a DMTL pump and did the replacement procedure posted from Gregg3gs.
Visually inspected the hoses and checked the connections at the wheel well side.
Looking for the next step or taking it to the dealer. MD has the worthless emissions inspection and will need to get this resolved so I can pass inspection and stop paying penalties.

[ard]

Originally Posted by wetzie

I
Looking for the next step or taking it to the dealer. MD has the worthless emissions inspection and will need to get this resolved so I can pass inspection and stop paying penalties.

I dunno...DOES keep people from driving around ignoring emissions issues!

I assume you have the evap hose diagram and have checked every single component??? not just hoses, but valves, fittings, even the tank?

[gregg3gs]

Originally Posted by wetzie

It would be great to follow this through to a fix. I am having the same code P0442 and is keeping the CEL on. The 2009 X5 3.0 is out of warranty and is sitting at 56K miles. It runs very well with no smells or hesitation. I purchased the BMWhat ap and reset the CEL and the X5 would run with no errors for several days. It starts with the check gas cap error and then later puts up the CEL a couple of days later.
I purchased a new gas cap and the problem came back quickly.
I then purchased a DMTL pump and did the replacement procedure posted from Gregg3gs.
Visually inspected the hoses and checked the connections at the wheel well side.
Looking for the next step or taking it to the dealer. MD has the worthless emissions inspection and will need to get this resolved so I can pass inspection and stop paying penalties.

wetzie - notice I updated the diy. I found my electrical connector melted, therefore the vapors were leaking out of the tank and generating the error.

[upallnight]

Originally Posted by Skyline

What caused that connector to heat up is not too much current, it's either a slightly loose connection, or a little bit of corrosion. The current bridges the poor connection, in return, making little tinny sparks, and causing heat. Certainly not the best thing around the fuel pump. If the problem reoccurs, I would clean the contacts and pins very carefully on that connector, and use some good contact cleaner on it. I might want to use some dielectric grease on the connectors as well.

Bad idea, the pump is submerge in the gas tank so gasoline act as a solvent to the dielectric grease.

[X5Cat]

Originally Posted by upallnight

Bad idea, the pump is submerge in the gas tank so gasoline act as a solvent to the dielectric grease.

Actually, the pin connection is on top of the plastic fuel pump housing, outside of the fuel tank. It is normally sealed off from gasoline, until you have a problem like this which results in a hole in the fuel chamber. Dielectric, I'm hoping, will reduce the chance of that hole reoccurring, thereby keeping the fuel and its vapors away from the connection.

[ard]

Originally Posted by X5Cat

Actually, the pin connection is on top of the plastic fuel pump housing, outside of the fuel tank. It is normally sealed off from gasoline, until you have a problem like this which results in a hole in the fuel chamber. Dielectric, I'm hoping, will reduce the chance of that hole reoccurring, thereby keeping the fuel and its vapors away from the connection.

Agree. Those pins are in air.


Contacts in a fuel tank are always a bad idea. TWA800.