We were test during a g37x and was testing the acceleration, when we floored it going 35, it shifted up and when it did so, it jerked back and forth sticking the rpms between 2500-3000, it wouldn't accelerate anymore and the engine, if you've ever heard it, sound like a two step. This g37x, 7AT, was stock, had 168k miles. When we took it out again it didn't do it, after several 100 times trying to recreate it, it didnt do it What could be causing this? There was no other problems with anything, owner was Asking 5250 for the car.

 

There should be full power and smooth acceleration at WOT. If the engine is surging, bucking, or exhibiting anything other than that and "hangs up" at a specific RPM then something is amiss.

I'm no rocket scientist but to me that is a red flag. Walk away. Just Mt 10¢.

 

The guy we’re buying from said that has never happened and after turning off the car and putting more gas into it, it went away. I might be a faulty fuel pump or just a bad sensor but no codes were thrown

 

You don't mention year but either way the fact that it happened at all is cause for concern. The hiccup may never happen again or it may drop dead 10 miles after you leave the seller.

Question is: are you willing to gamble? Are you prepared to go down the proverbial rabbit hole if the "hiccup" arises again?

Fuel pump failures are rare. Sensors, maybe. Oil pressure possibly. The 7AT is known for issues. Unknown history so who really.knows.

Only you can follow your gut. I'd walk away. There are plenty of other G's for sale.out there. Again, just my 10¢.

 

The owner is getting the car looked at by a mechanic before I buy it, if the mechanic says theres something wrong with it, id either make a lower offer or leave the car. BTW the car is an 09’ sedan