Pc007

Hi guys, car will make the normal noise when I turn the key, but the cranking sound continues and won't start...any idea?

Thanks

dprantl

When did it last start? What happened to the car between then and now, and how long has it been? Do you have an OBD2 code reader so you can read out any standard OBD codes?

Dan

"02996ttx50

fuel pump failure or battery w/out enough juice, but if turns over properly? i'd go with sudden and massive FP faiure.

do you know if its ever been replaced? the fp line inside ruptures constant issue..but usually you have some indication and warning signs. BUT it can "go" with a simple turn of the key so my money is one a failed fuel pump. keep us posted. it helps everyone to post the cause once found. GL w it!

wross996tt

check the clutch switch.

Macster

It is not clear from your post the exact behavior.

If the engine is truly cranking -- that you are not hearing what can be the rapid ticking/clicking noise of a starter solenoid being activated -- and not starting as others have offered the fuel pump has to be suspected.

They can die at any time and they do not have to give any early warning.

Not much you can do at home. Check the fuses. Swap out related relays or replace the related relays. When my Boxster fuel pump quit my local Porsche tech loaned me his bypass relay. You can buy these at the Porsche parts counter. I do not remember the cost but it was not high. But a bypass relay is probably overkill for the average car owner.

Another cause of a cranking but no start engine is the crankshaft position sensor (CPS) is not working. With this not working the DME doesn't know when to trigger fuel injection and spark. Since this is not an emissions problem the CEL will remain dark. A Porsche specific error code might be read from the car's DME but it would require at least a Durametric.

There is yet another possible cause. Low battery. Back in the day, the coils needed at least 9V -- it could be different now -- to generate the spark when the power is removed and the electrical field collapses. While the battery may have the juice to crank the engine a while the engine will never start.

However, I suspect you will find the fuel pump bad although as others have offered in the Turbo a fuel line may have failed and while the pump is working just fine one of the siphon jets is not working and the fuel pump is unable to use the fuel in one of the fuel tank basins. The fuel level will read about half full in this case.

The fuel pump fails more often than the crankshaft position sensor but if the fuel pump is eliminated as the source of the no start behavior the CPS then becomes suspect #1.

Pc007

Thanks guys!! The car last trip was last Saturday...worked fine...even a small issue I've had before with it, ( sometimes the turbo boost won't go over 0,4, when it should go up to 1,2...car has a repro, and gt2 intercooler, about 480/500 hp). Car has a battery tricker to keep it full.... It shouldn't be battery related...

Pc007

One more thing how do we check the clutch switch? Thanks!

Pc007

Just went to check it and battery level when I turn the key is a little above 12...like 12,7....are these normal values??

Pc007

Also one thing, whenever I started the car it would allways make a howling sound for 15 seconds on start and after...at this point it does none of that noise...

Carlo_Carrera

12.7V is normal and health.

FRUNKenstein

Concur with what the guys above said. Any chance you are having issues with the remote lock and unlock? Did you lock it with the remote and then unlock manually? Could possibly be something to do with the immobilizer.
My bet is on fuel pump or fuel pump relay failure. My '99 C4 coupe had a fuel pump failure with no advance warning. Drove it out to dinner with the wife on a Friday night and got a parking spot right in front of the busy restaurant. Came back out an hour later and it would crank fine but no fire. I tried swapping the fuel pump relay (same relay for a NA 996 as the 996TT by the way). Flatbedded it to my indy and he quickly diagnosed it as fuel pump failure.
Here's the thread: https://rennlist.com/forums/996-foru...5-minutes.html

Macster

If the clutch switch is at fault while the dash should light up when you turn the key the starter should not engage. The clutch interlock switch has to be working before the electricity is enabled to the starter solenoid.

If the starter is at least trying to engage if the starter is spinning the engine but the engine is not firing, that is not a clutch interlock switch.

"02996ttx50

while certainly true. the cps gives plenty of warnings in the form of cps related codes. the fp system isn't that helpful, and why i suggested earlier that is suspect number one. but hey, it's the internet. could be anything like the low battery. these things barely run with a low battery. not to be ( yet ) ruled out.

Kevinmacd

Turn the key to the run position, not the crank position, all lights should illuminate, at that time you should hear the fuel pump run, if not check the electrical circuit to the pump.
I Suspect the howling sound is the air pump running, which usually comes on when the engine starts.

Pc007

Yep...no howling sound anymore...but still the engine won't start...