im still fairly new to tbi and dont fully understand them yet so if i could get some help i would be greatfull,
anyway here is the problem, my car is making a knocking noise when it is up to running temp. but when it is started or still cold there is no knocking at all, also it has full power up until it starts to knock and then i have a huge loss of power.
ive run everything that i thought would be a possible problem through my head and im at a loss. any help you guys could give would be much appreciated.
thanks in advance
justin

also sorry if this could have been searched i really didnt know where to start and everything i searched for came up negative

 

sounds like a bad o2 sensor, resulting in severe fuel shortage.

I'ma go off on a limb here, if I'm totally wrong someone will correct me within the next 8 hours, so here goes...

the reason, I assume, that the car runs fine when you start it up is because for the first 8 minutes after you start the car, there are pre-determined fuel maps setup for the car, designed to help it help it get to running temps, once at running temps(the cat and o2 sensor are at the proper temperature to start working properly) your ecm will adjust the fuel/spark based off of feedback from various sensors around the engine, one of the most important being the o2 sensor, which tells the ecm how much fuel is in the exhaust gas. if there's too much fuel in the exhaust gas, the ecm will continue giving less and less fuel until the proper air to fuel ratio is achieved(14.7 on cars with cats), but if you're o2 sensor is bad or clogged, it will continuously tell the ecm that you're running rich to the point of oblivion, resulting in such a lean air/fuel mixture in your combustion chamber(as well as a serious amount of timing retardation) that you begin to create large amounts of knock, which I presume is the sound you're hearing, and would also account for the total lack of power.

whew.

anyway, change your o2 sensor and see if that fixes the problem.

oh, and do it soon, because that knocking is NOT a good thing for your engine.

 

thanks gonna do that tommorrow, i didnt even think about the o2 sensor
hopefully that will fix the problem
thanks again
justin

 

no prob, I just hope it fixes it.

 

k i replaced the sensor a little while ago and nothin still does the same thing any other ideas?
thanks in advance
justin

also do i need to reset the computer after replaceing the sensor?

 

Typically when o2 sensors fail, you run rich.

What type of knock is it? what does your oil pressure look like at temp? as the oil thins with heat, it could be that you are hearing a bearing that is going out.

If it is a pinnging sound, like then engine pinging, it could be excessive carbon build-up, or a timing issue, causing the pinging.

There are lots of possibilitys, without hearing the noise, it is hard to take a guess as to what it is.

 

oil pressure is fine about 60, and yeah its a pinging sounds almost like a loose lifter but comin from the bottom

 

what do you mean from the bottom? like, from the bottom of the motor? Have you noticed any brass filings in your oil?

 

i changed the oil right after the knocking started and i didnt see any kind of metal, and it sounds like it is comin from the lower passenger side of the motor