525iT FREEZES...condensation in the tank? HELP!

[aviatorb747]

HUGE headache this winter...Sometimes my car won't start on sub zero morning, then it need to be towed inside a warm garage and stats perfect after 2 - 3 hours. It happened at least 6 times this winter, I changed fuel filters, fuel pump, added lots of fuel tank antifreeze. Did anybody have same problem? Mechanics don't want to tackle this, tel me to add more isopropanol. Car runs perfect and that only happens SOMETIMES after it sits outside for a few hours in zub zero. Is there a wider problem of condensation in those metal fuel tanks?
I never had a problem like that with my 1990 300ZX, using same fuel....
I'll appreciate any advice.

[John B.]

Our 95 525i Touring starts fine right down to 0*F. What makes you think it's fuel related? What tests have you done?

[aviatorb747]

If it fails to start it WILL NOT start until it is put in a warm shop. I use engine block heater so it is not a cold engine issue. It never happened last winter, it started all the way down to -35 F. I am not sure it is fuel but I suspect it is moisture in the fuel lines.
?

[colo525i]

Do you live somewhere humid? you might want to check the charcoal canister to see if it is clogged/frozen. check the tank for any deformations or "woosh" when opening the tank cap.

[aviatorb747]

No, it is dry here. I moved from toronto to northern manitoba....What is really bad is that it happens once in a while, it started in september...I can't make it go away. Car runs perfect and starts fine for 2 weeks and then it will freeze up...I think I need to put more fuel line antifreeze and go for a long drive, burn it off.

[Ross]

No problem starting mine at sub- zero temps. Perhaps the block heater is fooling the temp sensor and cold start enrichment isn't being provided.??
If you are convinced it's due to fuel line freeze up do as advised with the fuel driers and burn off the whole tank.
You have checked the basic tune-up, right?

[632 Regal]

if your oil is thickening up such as dino oil i would blame it on that. I had a van that gave me probs just like yours until I switched (damn cold changing it too) try M1 0w-40, solved all issues with my stuff.

[Barney Paull-Edwards]

there may be a quick answer,go to oem parts page and buy a diesel E34 fuel filter,they have a heating element that helped mine start in Norway at -22.bin the rear in line filter too, so easier to get at as well.

[Barney Paull-Edwards]

Further to my last, I meant the under bonnet filter,should be easy enough to blow lines clear,drain tank to clear moisture and ****(common problem in Europe).

[DaveVoorhis]

HUGE headache this winter...Sometimes my car won't start on sub zero morning, then it need to be towed inside a warm garage and stats perfect after 2 - 3 hours. It happened at least 6 times this winter, I changed fuel filters, fuel pump, added lots of fuel tank antifreeze. Did anybody have same problem?

When I lived in Manitoba, I had the same problem every winter in almost every vehicle I owned. The solution was lots of fuel line antifreeze, make sure everything in the engine is working properly (check for vacuum leaks and ignition system weakness -- these can get worse in the cold), run oil with a low W viscosity, and make sure your block heater works. In one case (an early 80s full-size Ford Bronco with a 351 V8), I needed dual block heaters.