Fuel Rail Freezing? '98 A4 2.8
 

It's -20 and I've got fuel leaking out of 4 injectors and the flexible hose connector that goes to the rail. I tightened that some which seemed to work, but can't explain why there seems to be so much pressure.
Frozen fuel rail? Only started happening when -20 and goes away when it warms up. . .

Re: Fuel Rail Freezing? '98 A4 2.8
 

Hhhmmm, I originally typed up a reply that it was likely to be worn injector o-rings, but seeing that it's all four injectors and the supply lines that are leaking is just too much of a coincidence (although still possible). Is the engine running properly? Higher pressure right at the injectors seems very unlikely since that means that they would be injecting more fuel, causing your engine to run richly. Maybe the temperatures causing contraction in the materials, in combination with the often-increased ethanol content in Winter fuel (ethanol can damage rubber seals) is causing some leaks. I think you're going to need someone with good diagnostic skills to put hands on in this case.

Re: Fuel Rail Freezing? '98 A4 2.8
 

Thanks for the reply cheeba.

Car runs great, no check lights or anything. Seeing as I rebuilt the heads and installed a complete timing kit, even new rad, I figured I could have installed the fuel rail wrong. But it's all good, except when it hits -20. Gas is 91 octane.

This morning was not nearly as cold (-7), but before I fired up the car I heated up the rail with a ceramic heater, just as an experiment. Everything is very exposed as I left out any covers etc that don't need to be there, giving full access to the engine.

No leaks anywhere. . .

(This car doesn't have a block heater)

Fuel line antifreeze perhaps?

Re: Fuel Rail Freezing? '98 A4 2.8
 

I just realized that if the fuel rail was freezing then the fuel injectors wouldn't bubble out gas, so maybe they are freezing?

Re: Fuel Rail Freezing? '98 A4 2.8
 

No issues since it was -20, I'm blaming the 7-11 gas!