Infiniti G35 - 2 part question

Hi all - We have an 03 Infiniti G35 (automatic) bought new in late 2003 - it has 43000 miles on it now and is regularly serviced. This condition has been going on since my wife bought the car in 2003 (she says).

QUESTION #1: While driving once in a while, the car (at any speed) has a quick ‘hick-up’ which seems to be coming from the transmission. Its like the car skips - it lasts only a split second, and doesn’t repeat. There really isn’t any reason or condition that preciptates the skip - it is random. Does anyone have any comments or similar condition? Your comments would be helpful.

QUESTION #2: My wife (last week) told me that while she was stopped to get the parking stub while entering a parking garage - she stopped (to grab the stub), she doesn’t know how but (who know’s how) put the automatic transmission into PARK. When she tried to move - there was a grinding sound (like she was driving over something)- she moved only 3-4 feet and stopped. She said the car moved (like she was in DRIVE) - but she is positive the car was in PARK. I’m perplexed. Is this possible? And if so how much damage do you think could have happened?

The engine drives the transmission. The transmission is the link between the engine and the wheels. Why does she think the hiccup is caused by the transmission and not by the engine? Has anyone else experienced this hiccup? Ask a mechanic if there is a Technical Service Bulletin about this. You could ask at an automatic transmission shop, also.
The sound she heard could have been from the parking pawl dragging on its catch, and the gears (not the gear selector) may have been in drive… The transmission linkage may be worn and or out of adjustment. Another reason to visit a transmission shop.

I suppose my first response was to consider the transmission - never really considered the engine. Great advice! Unfortunately - it is so random that we experience the ‘hip-up’ that it may not be ‘felt’ by the transmission shop. I’ll let you know what we find out. But one other question - is this something you would consider to tend to right away? I only ask - since it has been doing it for quite a while.

I have thread on here with a similar problem (I think, not sure what a skip is). My 04 G35 has a hesitate when driving at any speed. No tranny noise of any kind however I live in MN and it usually happens when its snowing.

IE: If I am driving on the freeway at 65 mph (cruising) I will experience a quick hesitation as if I tapped the break but did not hold it down. The RPMs drop for a second then resume to its normal state based on the throttle position.

Havent been able to figure this one out yet however spring is approaching and monitoring it to see if the problems exist in the spring/summer as I did not have this issue last summer or the winter previous.

It’s snowing and you’re cruising at 65 MPH. Do you think the weather and ensuing road conditions might have something to do with it? BTW, do you have your cruise control on when this hesitation occurs?

no cruise control is not on. I think that weather may have something to do with it however it has happened when it is dry out (no snow or condensation on the road) and when the road is covered in snow. Its not a normal traction control feeling though, it is a definite jerk when it hesitates (almost like a fuel cut).
The only consistent thing that has been in effect is its been cold out when its happened.

I’m relieved to hear that the cruise control is off under those conditions. Your explanation left open the chance that you were using cruise control and going 65 MPH in the snow. If you are going that fast is it possible the hesitation might be hydroplaning? If it just started this winter it could be a coincidence, of course.

Hello, I have the same exact problem where my car randomly does a hiccup or a skip. My brother is a mechanic and he can’t figure it out either. I had recently gotten a transmission flush service and it’s still hiccuping. Did you ever figure out what it was?

No - nothing yet. It isn’t bad - but I’m wondering if it is a future issue. It paid for and I would like to get rid of the car sooner rather than later - if it was going to be costly.

The problem, as you describe it, seems to be intermittent misfire. A remote possibility is the torque converter lockup may doing a quick unlock, lock, unlock, lock. The lockup is set to occur at about 35 mph, road speed going up, or coming down (unlocking). The erroneous locking/unlocking, at 65 mph, could be checked by disabling the TCC lockup by pulling a fuse or disconnecting an electrical TCC connector. If the hiccups, then, didn’t happen…you have a suspect.
Some mechanics will appreciate this tool in finding a causes of intermittent engine action; but, none will have it: