Replacing the air intake hoses? HELP.

[chairmankaga]

2007 M35. Changing my spark plugs today I discovered both of the air intake hoses were torn. I called Infiniti parts and they want $200 for the entire intake assembly (box, both hoses, resonator), and don't sell the hoses individually. I don't think any of the other cars using the VQ35 have the same layout or couplers. Maybe the G35? I know the Nissan cars don't. I also can't find any aftermarket options.

I'll try to ShoeGoo the old ones to mitigate leaks until I can find a solution.

Any ideas?

I wonder if this might explain my terrible fuel economy. Unmetered air = lean mixture and excessive heat in the combustion chambers. Awesome.

[Ilya]

There is a few threads with this issue, look for the term 'coupler' in your search and you'll probably come across them. I've linked products I've used cause I had the same issue. I recommend a Z-Tube (Stillen) and intake hoses.

[chairmankaga]

I ended up getting the whole OEM assembly. I know a guy at the dealership and only paid $120 for it. I think actual retail full-price it's close to $300. But mine was REALLY shot. Torn almost completely around near the airbox and about 50% around at the TB. Noticed the throttle was immediately smoother once I got the new one in, so maybe this'll improve performance in general.

[Larz]

That's a great deal! I replaced mine with blue HPS hoses to match the blue oil filler cap but saved the OEM just in case I decide to change back. Somehow my OEMs still look and feel new. Maybe since we don't get the harsh weather, etc that you lot get up north.

[chairmankaga]

I'm just really curious to see if the old hose was negatively impacting performance and efficiency, and if so how much. The MAF sensor is in the air box, right? Or is it in the TB assembly? I guess that would be the main determining factor. Pre-leak, the car would be lean and the sensor wouldn't detect. Post-leak the ECU should be able to compensate and I'd only be getting dirty air, but not too much. But that would still cause the ECU to enrichen the mixture, so I should at LEAST see some improvement in fuel economy (presently 17.1 MPG in mixed, mostly highway, according to GasCubby).

[EdBwoy]

I'm curious too. Although I think it might be rich rather than lean... at first.

For example:
MAF sensor (in air intake tube) says it's receiving 14.7 ml of air per second, so at cruising the ECU asks the injectors to deliver 1 ml of fuel for the ideal stoichiometric ratio of fuel:air = 1:14.7
However, say you lose 1 ml of air through through gaps in the intake after the MAF sensor. In reality you are burning rich as more fuel to air equaling 1:13.7 instead of the ideal 1:14.7 ratio.
Which would make you think you're actually burning more fuel, right?

The second part is the feedback loop by means of the primary oxygen sensor AKA bank 1or 2 sensor 1 AKA air fuel ratio sensor.
These look at the combustion products for oxygen concentration and if lower than expected, will ask the ECU to reduce fuel to match. On the other hand, if too much oxygen is sensed, then the ECU pumps more fuel to correct the lean situation.

Either too lean or too rich beyond the ideal range for the car could result in lower fuel economy depending on what the car is being asked to deliver... but that's a story for another day.

[airmanhoward]

Are you guys talking about this part

https://ibb.co/kS5c8a

[Ilya]

Yes, those boots rip over time.

[airmanhoward]

Pulled one from a maxima at the junk yard

[chairmankaga]

Yeah, but it was the 45-degree hose from the resonator to the TB that was in the worst shape. Mine basically disintegrated when I pulled it apart to get to the plugs. I couldn't afford to wait for one to turn up in the junkyard or come from whoever on eBay, and the local dealer had the whole rig in stock.

[MikeLarrym35]

I found this i just installed it on mine.. it was a lil snug on the smaller end but it works great!!!
https://www.amazon.com/gp/product/B00Y9 ... UTF8&psc=1

[airmanhoward]

I found this i just installed it on mine.. it was a lil snug on the smaller end but it works great!!!
https://www.amazon.com/gp/product/B00Y9 ... UTF8&psc=1

Yes the max is a little snug but it works