1998 engine rattle and knock

my sister's 1998 breeze 2.4L 4cyl has developed awful engine knocking and rattling. it gets worse when the ac is turned on. supposedly it has a damaged oil pan. i think she said the service tech at wal-mart said it was bent or something like that. is this a common problem with these cars? and what might the problem be? it has had all the regular maintenance performed for the past 10,000 miles that shes owned it, about a year. it has approx 91,000 miles and she got it with about 80,000. any service done before that time cannot be verified by her since she got it from a used car lot. presumably it has had all regular maintenance performed from the time it was bought new. any help or assistance anyone can provide would be greatly appreciated. thanks.

The most serious issue is the bent oil pan. I am not sure if this will cause your noises, but I have a 1997 and 2000 Stratus with the same engine. The 97 has a cast aluminum oil pan, and the 00 has a steel oil pan. If your sisters is cast aluminim, it will not bend, it will break. It will be a light aluminum color, where as the steel pan will be dark, if not black. Underneath the pan, in the section that drops lower than the rest of the pan is the oil pickup tube for the oil pump. If the damage on the pan is there, the oil pump cannot get all the oil it needs to supply lubrication to the rest of the motor. Also underneath the pan is the balance shaft carrier assembly. If that is damaged, you may be getting noises from there. You should drop the oil pan and visually check these parts. If the pickup tube is damaged, replace it. If the carrier assy is damaged, it needs to be replaced. The balance shafts are turning at twice the crankshaft speed, and if there is a problem there, they can lock up.

If the noise is coming from the A/C Compressor, the possible cause is the shaft bearing or the clutch is wearing out. The clutch pulley on the compressor is always turning when the motor is running. When you turn on the A/C, an magnetic clutch engages and the pulley begins to turn the compressor. If this is the case, the noise will get worse, because the engine has to work a little harder to turn the compressor and pump the freon through the entire system.

in my earlier post i was mistaken about one thing...it has a 2.0L engine, not the 2.4....would that make any difference as to what the problem might be?

The only difference is the 2.0 does not have the balance shafts. Everything else I would still check.

I have a 97 with a 2.0 liter. Also had a knock and rattle when I used the a/c or climbed a grade, thought it was the heat shield on the exhaust manifold, but I was wrong the cat baffles were loose causing all the noise

well my cat baffles are loose as well and looking for a diagram that shows me how to install new converter i got from online its the direct bolt on oem

well my cat baffles are loose as well and looking for a diagram that shows me how to install new converter i got from online its the direct bolt on oem

If you have the direct fit cat, it is not very hard to swap this. All you should need is a set of ramps and a couple of extensions to reach the bolts up on the manifold. Dont forget to take off the o2 sensor first ,or at least unplug it so you dont tear off the wiring.