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cracked manifold=poor performance?

Poor fuel ecconomy, poor idle and hesitation accelorating are some. Other things can cause the same problems, like a bad O2 sensor or a vacum leak.
Tom
 
Huh...thats funny,I've had all those symptoms since I bought the jeep 3 years ago.

I always thought it was a sensor so I've darn near checked/changed every sensor.Recently I've been paying attention to the manifold leak I have and wondering if it has been the source of my rough idle/stalling/bucking(5speed)problem.
 
jeepdeepfreak said:
Huh...thats funny,I've had all those symptoms since I bought the jeep 3 years ago.

I always thought it was a sensor so I've darn near checked/changed every sensor.Recently I've been paying attention to the manifold leak I have and wondering if it has been the source of my rough idle/stalling/bucking(5speed)problem.
Click to expand...

Is that a good possibility?
 
The manifold being cracked will REALLY lead to alot of problems(see above), since you basically have a place for fresh air in enter the exhaust stream ahead of the O2 sensor, the computer is tricked into thinking that there is a lean condition in the motor, and tries to correct it by adding fuel to fatten up the mixture, which leads to bad economy, and a possibly "smoked" converter from the over-rich condtion. The O2 sensor will also tend to have a shorter life because of the excess fuel "coking" or sooting up the element inside it. Let's also not forget that this cracked manifold can be a POTENTIAL place for a fire to start, since oil, grease, and fuel lines are close to this area.
 
ren said:
The manifold being cracked will REALLY lead to alot of problems(see above), since you basically have a place for fresh air in enter the exhaust stream ahead of the O2 sensor, the computer is tricked into thinking that there is a lean condition in the motor, and tries to correct it by adding fuel to fatten up the mixture, which leads to bad economy, and a possibly "smoked" converter from the over-rich condtion. The O2 sensor will also tend to have a shorter life because of the excess fuel "coking" or sooting up the element inside it. Let's also not forget that this cracked manifold can be a POTENTIAL place for a fire to start, since oil, grease, and fuel lines are close to this area.
Click to expand...
Oh My God!


did this kill Kenny?

I drove my '90 for 40,000 miles with number 6 cracked all the way around and a two inch crack in number 5. Welded up the cracks and put another 40,000 on it with no appreciable change in gas mileage or drivablility. The only obvious difference was the improved sound.

YMMV
 
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