My Audi TDI won't start in the cold (like 0 degrees "American" cold)

[Scottintexas]

hopefully this is just a one time issue with the extreme weather, my truck has a block heater for extremes.

2014 Audi Q5 TDI, 150k been running great,

-2 and now it won't start,
push the start button
glow plug light comes on a few seconds
engine cranked for 2 seconds it fired for 3 seconds then died
push the button again, engine cranks for 2 seconds but does not fire,
did this 5 more times and figured the battery was going out, it's a few years old, replaced it with a 850cca expensive battery,

it cranks for up to 10 seconds but never fires,
I put a hairdryer on top of the engine near what I believe is the "pre-filter", it's just after what appears to be the fuel line coming up from underneath on the front, driver's side of the engine, (I've changed the fuel filter underneath the car before)
after 30 minutes with a towel over it for insulation,
it cranks, fires and runs for 3 seconds (enough to say "oh! it's fixed" and then dies,
30 more minutes with hairdryer does the same thing, 5 times now over 2 days,

I feel like it's gelled fuel, is there a better or more places to put the hairdryer to thin it out ? I'm close enough to warmer weather I can just wait it out but just trying to get to know it a little better as I wasn't expecting this, in the future I'll run some additive when I know it's going below freezing,

@veedubtek

 

[Miitch]

Diesel fuel gels around 10 to 15F, so thats most likely the issue. Prolonged exposure to these temperatures (days at a time with no start) would cause an issue.

I have a 2015 VW Golf TDI. I drive it every day 120km round trip to work and i dont have an issue. We have the same temperature right now, 2°F and lower. However, my 2015 golf does have a small block heater? I use it when the temp drops below -5°F. I hook it up to a timer so it comes on 1 hour before i leave for work. Seems odd that your one year older Audi doesnt have one? are you certain?

Edited to mention last winter when i took a week vacation to go skiing and wasn't driving my car to work, after leaving it sit in the 0°F weather for 3 days, the diesel had gelled.

 

[swatski]

Probably not the motor but the fuel!
Light a small fire under it?

Or just drive one of @Betik's cars, he does not leave his house for another year, afraid of the virus.

-

 

[ChrisM]

My thoughts exactly, gelled fuel. My Ford has both block heater, and fuel bowl heater. TX probably not receiving winter mix diesel?

What's the Deal with Winter Diesel Fuel? - NW Fuel

 

[Scottintexas]

Google Image Result for https://media.tenor.com/n8cKPxSViZ0AAAAM/car-drift-winter.gif

The last time betik lent me his truck in the snow!

 

[zipper]

Can you light the glow plug without cranking the engine? If you can, do it a half dozen times, before you start it. We do have the Winter mix here. I find that the off road diesel, kerosene does not gel and I run some of that mixed in when really cold, especially in the tractor. If the parrafin did solidify, put a heating pad around the filter. My truck starts at 3°F by leaving my glow plugs on for 10s or so before starting. Last time i knew I had 4 bad glow plugs and it still started this morning. My plug in heater only works below 0.

 

[AT4TX]

We do get winter mix, but it’s usually only found at truck stops and co-op/rural stations. Blending #2 and #1 at a 70/30 ratio works. Treating the tank with a CFI above 32F works too. I plugged my block heater in before the storm hit and so far so good.

 

[Scottintexas]

Balmy 27 this afternoon, started right up!

 

[Betik]

Don’t know what y’all are taking about trucks. My truck is sitting at 60 degrees garage next the boat. I have been driving the Prius these last couple of days. And needles to say I have been putting some Suburbans to shave.
Though here where I live the first year thing is to see people on Range Rovers with the airbags fully lifted and doing like 15 mph. It must have terrorizing to see a Prius zip by at 40 LOL

 

[FSH 210 Sport]

You probably don’t have winter blend diesel there in TX... Diesel fuel can start to gel at 30* if the fuel quality is not that great. Even with winter blend diesel I still run Amsoil cold flow improver along with the Amsoil cetane booster and injector clean / lubricator. By adding the cold flow it reduces the gel point to -30*. If you have a water fuel separator you should be draining that regularly as well.

Glad it started it up for you today!

 

[PeterB]

@Scottintexas glad you’re up and running. My diesel fuel has been ok - good winter mix here in IL - but my def froze and the pump crapped out - so driving my wife’s Arcadia today.
I bought my Canyon in Austin Tx - drove to Illinois - and then the windshield fluid froze. Guessing in TX nobody really prepared for extreme cold the way people in colder climates do. Point being - even if you have a winter blend diesel in your area the mix is likely not intended for extreme cold, If it gets cold again you may need to blend some #1 diesel in your tank - more kerosene =lower gel temp but robs power so it’s a balancing act

 

[Scottintexas]

thank you for all the replies, at 24 F the car started this morning again without issue,

I'm sure it is a fuel/gel issue and if I expect to be in temps under 20F again I'll be adding some AMS cold flow to the tank before hand,

this caught me off guard as my IDI doesn't usually get used in extreme cold but I do expect the Audi to go on some ski trips and encounter 0F weather occasionally, I guess at least Audi has the DEF heater figured out as a quick internet search doesn't bring many hits on that issue

 

[FSH 210 Sport]

You probably would not have had any issue if there had been winter blend in your tank from the filling station...the Amsoil cold flow is cheap insurance. Most all modern diesels do not have trouble with the DEF system, as they have electric heaters in the tank, I’m pretty sure that DEF’s freezing point is 12*F.

Again, glad your Audi is up and running!!!