Z4 Will not start, but starts after being towed!

[mz4]

I have a 2004 Z4, 2.5i. Over the past weekend it would not start at all. The engine would try to turn over but wouldn't. So I called to have the car towed to a mechanic.

The wrecker driver pulled the car onto the flatbed, and decided to fun to fire it up, and guess what........it started! Now I let it sit over night and here is what happened today:

1. As soon as it started it sputtered and died
2. Started back up immeidately
3. Drove it 17 miles into work
4. After parking I turned it off and tried to restart it, and it started and died again!

Any suggestions on what could be wrong?

[Syaka]

I have a 2004 Z4, 2.5i. Over the past weekend it would not start at all. The engine would try to turn over but wouldn't. So I called to have the car towed to a mechanic.

The wrecker driver pulled the car onto the flatbed, and decided to fun to fire it up, and guess what........it started! Now I let it sit over night and here is what happened today:

1. As soon as it started it sputtered and died
2. Started back up immeidately
3. Drove it 17 miles into work
4. After parking I turned it off and tried to restart it, and it started and died again!

Any suggestions on what could be wrong?

Let me ask the obvious question first, have you checked the battery / terminal cables?

[The HACK]

Fuel delivery. Either the pump is going or the fuel pressure regulator is on its way to a premature demise.

At least that would be my wild @ss guess.

[mz4]

checked the battery. its fine, even tried to jump it when it was dead.

I think The HACK may be right. Do you know if there is a diagnositic that can be run to see if it is the Fuel Pressure Regulator or Pump?

[The HACK]

checked the battery. its fine, even tried to jump it when it was dead.

I think The HACK may be right. Do you know if there is a diagnositic that can be run to see if it is the Fuel Pressure Regulator or Pump?

Sure, it's called a GT1. It's a fancy computer that plugs into your OBD-II port and cost about $20,000.

If you're out of warranty, make sure the mechanic you're taking the car to has a GT1, otherwise you'll spend the next 2 weeks and money on labor/parts trying to chase down the problem. If you're taking the car to the dealership, they'll have a GT1 handy.

[mike87]

Sure, it's called a GT1. It's a fancy computer that plugs into your OBD-II port and cost about $20,000.

If you're out of warranty, make sure the mechanic you're taking the car to has a GT1, otherwise you'll spend the next 2 weeks and money on labor/parts trying to chase down the problem. If you're taking the car to the dealership, they'll have a GT1 handy.

holy hell $20,000?

[The HACK]

holy hell $20,000?

That's what my mechanic friend who bought one told me. Although it was expensive he said his shop couldn't function without one, especially with all the newer BMWs requiring it for accurate diagnosis.

Part of the cost for doing business as an independent BMW mechanic I guess.

[car62]

Intermittent electrical problem or fuel problem. Common culprits are fuel pumps, ignition coils, engine computers, air flow meters, and relays. If there are any BMW techs on here they may be able to name something that is especially typical of that model. Probably you will have to have it diagnosed by the dealer, unless you get lucky and find the problem immediately.

[boot]

I have a 2004 Z4, 2.5i. Over the past weekend it would not start at all. The engine would try to turn over but wouldn't. So I called to have the car towed to a mechanic.

The wrecker driver pulled the car onto the flatbed, and decided to fun to fire it up, and guess what........it started! Now I let it sit over night and here is what happened today:

1. As soon as it started it sputtered and died
2. Started back up immeidately
3. Drove it 17 miles into work
4. After parking I turned it off and tried to restart it, and it started and died again!

Any suggestions on what could be wrong?

I just had this same thing happen to me a few weeks ago, not with a z4 but a Mercury Sable, I also thought fuel pump or regulator but, fuel pressure was good, while trying to find the problem over a few days the battery went dead changed the battery and have not had a problem since maybe the battery was weak and screwed up the computer computer was reset when battery was changed and good as new

This was the 1st problem that the Mercury has ever had in 53k miles, Never once back for warranty work.

[The HACK]

I'm not entirely sure about the di-Sable's electrical systems, but on modern BMWs it takes all of the battery's crank power to turn the engine...A weak battery would just go clickety-click.

Wouldn't hurt to check it.

[guney]

Sure, it's called a GT1. It's a fancy computer that plugs into your OBD-II port and cost about $20,000.

Of course, it couldn't hurt to start by trying your luck with a $60 OBD II code reader to see if you'll find a diagnostic code that may explain something (unless you've done that already).