New battery in 03 VW Passat, engine turns but will not start.

I suggest that you go to an auto parts store and have them run a diagnostic it's usually free. If not you can purchase a small diagnostics tester for around $50. A thumbs up would be greatly appreciated if this answer is helpful to you. Have a GREAT DAY and GOD BLESS YOU.

could b ur autonatter

cold weather kills batteries this time of year...heres why..most batteries are a chemical factory..the acid and water separate as the battery discharges..also the chemical process is lessened when the air temps go below freezing by around 50% or more depending on the age of the battery..in extreme cold areas, external heat sources are required to keep engines warm enough to run..in alaska for example,the batteries are taken out entirely and put inside to keep warm..sometimes a fire pit is used to warm the engine from below (red hot coals no flame)..also in very cold weather, the engine oil will get very thick..in some cases the oil will actually glue the engine semi solid..locking it up..if its a cheaper oil that whathappens..I like 20 miles north of st louis in illinois and when it gets below 30 degrees outside i place a under cabinet 350 watt heater(used for keeping food warm to serve) upside down under my engine overnite..this keeps the block warm and the oil thinned out..and works very well for me..my car will start whe no one elses will in my neighborhood..hope tyhis helps you..

check battery cables make sure they are clean and tight and make sure the alternator charging battery. first check battery volts. should be 12.6 volts. with engine running alternator out put at battery should be 13.5 - 14.5 volts. if not either alternator failed.check alternator power feed wires and voltage regulator wires for damage or make sure electrical wires has tight connection.check alternator battery.first turn off radio before before disconnecting negative battery cable.

Sounds like temp sensor that controls fan is faulty.This would cause fan to stay on all the time or not turn on at all.

cold can do some damaging things to our bodys-like skin etc--it does the same to aging engines-inspect what parts u can and titen any needed

possibly ajusting itsself. any severe weather/pressure changes in your area? and if so does your cars cpu compensate for this (thinks its at a different elevation etc then resets its idle proper after a certian time? I have heard of this but not sure if VW uses it) perhaps ask the service tech.

VAG suffer greatly with a signal failure to ECU that brings the choke on when cold. Your fault is text book of this.

Follow the top radiator hose to where it meet the engine, at that point you will see a sensor, it has 4 wires and is held in by a horseshoe clip. This is the water coolant sensor, replace it and you'll be happy again :o)

The car is having overheating problem,its not battery(change top gasket)

99 vw passat 1.9tdi was driving sound but just died just turns but wont fire up