Does a cracked manifold effect gas mileage?

C

canadianwheeler

NAXJA Forum User

Location

canada

• Oct 5, 2005

• #1

My 92 xj gets very crappy gas mileage (13 mpg) just like all most everyone one else. I have changed everything on it that people suggested and it has not made a difference. I noticed the other day that my manifold has a crack in it. Could that crack effect my o2 sensor enough to effect my gas mileage? If so how much??

BTW its a 92 xj 4.5 inch lift on 31's

 

Yucca-Man

NAXJA Member # 683

Location

Castle Rock, CO

• Oct 5, 2005

• #2

Yes, it can have an effect on your mileage because you're not getting a true picture of the exhaust. The added heat dumped into the engine bay is definitely not a good thing either...

 

5

512TR

NAXJA Forum User

Location

Norway

• Oct 5, 2005

• #3

The O2 sensor will probably sense more oxygen in the exhaust and send signals to the PCM to give the engine more fuel, as a result the A/F mixture will be too rich in closed loop operation (warm idle and cruising), and the mpg will go down.

 

C

canadianwheeler

NAXJA Forum User

Location

canada

• Oct 5, 2005

• #4

I cant afford a new manifold and i dont have acess to a weldeder is there any temporary fix? I know u guys are gonna laugh but what about JB weld?

 

Yucca-Man

NAXJA Member # 683

Location

Castle Rock, CO

• Oct 5, 2005

• #5

JB Weld will melt off - discussion about it less than a week ago. The manifold temps are too high for most putties and bandage fixes.

 

karstic

NAXJA Forum User

Location

Milwaukee

• Oct 5, 2005

• #6

canadianwheeler said:

I cant afford a new manifold and i dont have acess to a weldeder is there any temporary fix? I know u guys are gonna laugh but what about JB weld?

Click to expand...

Take it to a local muffler shop. If it's in an easy to access area, they can weld it up.