Help--Engine dies without warning at various speeds

[jamesw]

Hi,

I have a 2001 Boxster S, with a 5-speed manual transmission. It has 53k miles. I know basic car mechanics, but the electronics on this car are beyond my knowledge.

Overall my Boxster has been a terrific car. However, I am now experiencing an odd intermittant problem that I do not know how to solve. The car runs perfectly most of the time. However, for the past several months, on rare ocassions and without warning, while driving the engine has suddenly cut out and died. This has happened at 5 mph, 75 mph and various speeds in between. On several occassions when this occurred at high speeds on busy freeways, I felt lucky that I did not have an accident.

When this problem occurs, the symptoms are always exactly the same. While driving, the engine suddenly dies, and all of the lights on the dash come on at once. There is no sign of trouble until after this occurs. Once the engine dies, it will not restart for at least 5 minutes. If I try to immediately restart it, the engine will easily crank over, but will not catch. It sounds like it is out of gas. If I wait a few minutes and try cranking it again, the motor will cough and sound like it is almost catching, but not getting quite enough gas. After 5 minutes, I can usually restart the engine if I crank it over without giving it any gas. Once the car restarts, it runs perfectly until the problem occurs again. At no time has the check engine light ever come on by itself. Also, this is not a problem associated with bad gas. The problem has occurred at different times with different gas, and with the tank at different levels.

I need to find the cause of the problem ASAP, because I cannot drive this car never knowing when or where it will die on me.

I have taken the car to my mechanic for the problem twice. I have been using the same mechanic for years, and he is very knowledgeable and experienced with Porsches and other European cars. He checked the car and found nothing wrong with it. He replaced the fuel pump relay at my request and tightened up several loose wires behind the fuse box. He checked the MAF sensor, but did not believe that to be the source of the problem. Other than that, he could find absolutely nothing wrong with the car. Has anyone else had a similar problem, and, if so, what turned out to be the cause of it?

[Loren]

You need to have the fault codes read and report them back here.

If there are no fault codes then you will need a PST2 or PIWIS tester to do further diagnosis. If your mechanic does not have one of the these tools you need to find one that does.

[ericinboca]

Hi,

I have a 2001 Boxster S, with a 5-speed manual transmission. It has 53k miles. I know basic car mechanics, but the electronics on this car are beyond my knowledge.

Overall my Boxster has been a terrific car. However, I am now experiencing an odd intermittant problem that I do not know how to solve. The car runs perfectly most of the time. However, for the past several months, on rare ocassions and without warning, while driving the engine has suddenly cut out and died. This has happened at 5 mph, 75 mph and various speeds in between. On several occassions when this occurred at high speeds on busy freeways, I felt lucky that I did not have an accident.

When this problem occurs, the symptoms are always exactly the same. While driving, the engine suddenly dies, and all of the lights on the dash come on at once. There is no sign of trouble until after this occurs. Once the engine dies, it will not restart for at least 5 minutes. If I try to immediately restart it, the engine will easily crank over, but will not catch. It sounds like it is out of gas. If I wait a few minutes and try cranking it again, the motor will cough and sound like it is almost catching, but not getting quite enough gas. After 5 minutes, I can usually restart the engine if I crank it over without giving it any gas. Once the car restarts, it runs perfectly until the problem occurs again. At no time has the check engine light ever come on by itself. Also, this is not a problem associated with bad gas. The problem has occurred at different times with different gas, and with the tank at different levels.

I need to find the cause of the problem ASAP, because I cannot drive this car never knowing when or where it will die on me.

I have taken the car to my mechanic for the problem twice. I have been using the same mechanic for years, and he is very knowledgeable and experienced with Porsches and other European cars. He checked the car and found nothing wrong with it. He replaced the fuel pump relay at my request and tightened up several loose wires behind the fuse box. He checked the MAF sensor, but did not believe that to be the source of the problem. Other than that, he could find absolutely nothing wrong with the car. Has anyone else had a similar problem, and, if so, what turned out to be the cause of it?

Might be a dying fuel pump. When hot, they can begin to fail. Once cooled off, they run again until too hot.