I have a 2003 g35 sedan. My husband was driving it and the engine lost power, pedal to the floor and it would not go any faster. Temperature shot up to hot and the car died. Started it back and it's making a horrible banging noise under hood. Heard it could be oil pump failure!? Any help would be greatly appreciated. Not sure if we should buy new oil pump or new engine!? Thanks in advance for any advice.

 

Highly recommend a proper mechanic diagnosis, but at a minimum get the engine trouble codes read. You can buy a reader pretty cheap online.

It sounds like a head gasket failure :/. Loss of compression (power) comes from that.

 

we have already run the codes. Showing code for crankshaft position sensor. Done changed that. Already had heads redone. Car lost compression and then ran hot. Leads to oil pump failure according to research I've done.

 

A horrible banging is a sign of a thrown rod as well. That would also cause the car to lose power and could have been caused by a faulty oil pump. If the pump failed something else will fail due to starvation so at this point you need a mechanic to physically diagnose the issue. Not much more we can tell on the internet. Sorry to hear this happened, it's a very uncommon issue with the G's.

 

Yeah I've heard from several Infiniti mechanics that the motors in the g35 are normally amazing motors. Very disappointed. Well soon as I know the problem I'll post it here. Thanks for any advice.

 

Why don't you drain the oil and cut open the oil filter? If there are metal particles in the oil or filter then you know there was metal on metal contact. You should also hook an oil pressure gauge and see what it's reading. Although, it's called an oil pump it doesn't actually create the oil pressure that's from the clearances between the bearings and what not.

That banging could be rod knock though...