Avensis Engine Running Rich On Fuel?

[airconuk]

Well i replaced my 2004 1.8 avensis engine that had needed new big end bearings due to lack of oil aparantly.The new engine i had put in had done 15k miles before i bought it from a scrap yard. I have driven around 1k miles on it now, and the engine seems to be running at about 25 mpg rather than the usual 30-32mpg it was doing on my old engine. another problem is that i have found it is a cosiderably deeper and loder sound that my old engine. there isnt any knocking or tapping of any sort, its just a deep roar when it is revved. I came to a conclusion that it may be running rich on fuel, and the o2 sensor on the new engine may have a prob, so i put the old o2 sensor on, but still no luck, anyone got any ideas??

thankd

by the way it is engine 1zz-fe

[jamesholden]

Well i replaced my 2004 1.8 avensis engine that had needed new big end bearings due to lack of oil aparantly.

The 1.8 VVTi's have a habbit of burning oil, you should have taken it to Toyota and they would have replaced the engine for free upto about 7 years old if it was using oil in quantity.

Can't really help with your current problems though i'm afraid.

[Q.S.]

Well i replaced my 2004 1.8 avensis engine that had needed new big end bearings due to lack of oil aparantly.The new engine i had put in had done 15k miles before i bought it from a scrap yard. I have driven around 1k miles on it now, and the engine seems to be running at about 25 mpg rather than the usual 30-32mpg it was doing on my old engine. another problem is that i have found it is a cosiderably deeper and loder sound that my old engine. there isnt any knocking or tapping of any sort, its just a deep roar when it is revved. I came to a conclusion that it may be running rich on fuel, and the o2 sensor on the new engine may have a prob, so i put the old o2 sensor on, but still no luck, anyone got any ideas??

thankd

by the way it is engine 1zz-fe

Try checking out your inlet pipes/hoses/airbox/air filter. Sounds like your describing induction roar.

[airconuk]

i spent saturday under my car as i was trying to solve a squeak thnat was comnig from under my car when idleing. inthe process i fould that i had forgotten to put the gasket or seal in between the exahaust and exhaust manifold. After trying the engine afterwards, it solved the squeak and the roaring so it must have been an exhaust leak. However i have no way of telling if it has fixed the low mpg as i have not yet driven the car much