My 2003 350z Track Edition has around 93,000 miles. For the past two weeks, I've noticed that my car will lose power noticeably for a split second while driving, or even stall if at idle. I feel as if the drive train re-fires the engine and doesn't allow it to stall at speed. At first it was a very subtle loss of power, and now has progressed to a noticeable step change and abrupt split second deceleration. Initially there was no engine light, but today I got a Service Engine Soon Light, and a second later the VDC off and SLIP lights also illuminated. This abrupt momentary power loss will happen almost once a day now it seems.

I think it might just need a 90k tune up that I haven't gotten around to yet, but anyone have any ideas on what directly could cause this? Timing belt perhaps?

 

Could be a cam position sensor. These go out often and at your mileage its very likely. Just changed one of mine the other day, had similar issues as yourself.

Whatever it is I wouldnt drive the car until you get it fixed. Last thing you want is your car losing all power while on the freeway.

 

Thanks for the heads up, I'll diagnose the CEL tomorrow afternoon and try to get it repaired ASAP... unfortunately, she's my DD at the moment because my actual DD blew a headgasket and is sitting in a shop.

I've lost a wheel driving on the freeway before, losing power shouldn't be much worse

 

Without a diagnostic code we are guessing. And guesses are worth spit.

 

Yea check into that Cam sensor, but also, believe it or not I had similar symptoms when my brake fluid was low and pads needed to be changed. The car would randomly hard decelerate and catch me off guard. (I'd almost feel like my face would hit the steering wheel lol) Then the SLIP, Service Engine, and VDC lights would come on.

Changed the front pads, added brake fluid and it never happened again (1 year later).

 

Yeah, it was the Camshaft Position Sensor, P0345. Was going to fix it tonight, but my toolset has gotten seriously weak, and I don't have an allen socket to take the throttle body off to get to the sensor....

I'll fix it tomorrow. Driving shouldn't damage the engine if it's otherwise running normally right? It starts fine, and is derivable. I'm assuming it's using either a crankshaft sensor or the other cam sensor as an alternate?

 

Just out of curiosity, could your cam sensor go bad, and it NOT throw a code? I've had similar symptoms recently but have no Cam Position code.

 

Question; do your gauges continue to read properly during the split second the power cuts out. If you notice a "blip" in the gauges I would suspect a loose/corroded battery cable.

 

No, I visibly have noticed power fluctuations in the RPM gauge during temporary momentary power loss.

And YES, you can have no CEL with a faulty Camshaft Pos Sensor... I had symptoms before having the check engine light. Also, I haven't replaced mine yet, and the light turned off, but I'm sure it will fail entirely soon (since I read the code and confirmed it while it was still on).

 

I had my CPS's both replaced( but not harness's) along with knock sensors after she threw CEL's and coded for CPS. was symtomatic with starting prior for about 2-3weeks. But.....

its been about almost a month since the repair and its become symptomatic minus the starting issues once again. Acceleration boggs down between 2300 to 3000rpms before picking up at WOT, felt mostly in 1st thru 3rd.
car has 79Kmiles and full intake/exhaust bolt ons with Reflash.

Any suggestions where/what to start looking at???

 

I am also having this issue. About 142k, maybe about 60k on motor. On normal hwy cruising I get a brief cut in power like a split second. Doesn't drop rpm.

 

Same thing happened with my car (2003 Performance model). The car began running rough and sometimes even cutting out completely at low speeds. I replaced the Camshaft Position Sensor, and that fixed the problem.

But, the problem came back within a couple of weeks. I returned to the dealership and they came up with the identical diagnosis and replace the Camshaft Position Sensor a second time. Their explanation was that the initial sensor was faulty.

The car has worked fine since the second replacement.

--Spike

 

So my car had loss of power today and the service engine soon light came on. My question is should I take to dealer to diagnose/check the codes and fix it? Or is this something my mechanic can handle?

 

If one is capable of plugging a cord into a wall then ANYONE can pull a code. Fixing it depends on whether your mechanic will understand the Nissan interpretation of the code.