Loud rattling noise

[jaypurce]

My 99' Grand Am SE has been having some issues. Firstly, my car countinues to misfire. It misfires intermittently in cylinder 4 (P0304). The problem does not lie in any of the following: fuel injector, spark plug boots or spark plugs. I don't know what it is. But just today, my car has been making a very loud rattling noise while driving. The sound gets louder as the rpms go up, and continues to get louder until it gets into a higher gear. My car is also using/ going through a lot of oil. I put 2 quarts in about 1.5 days ago and the low oil light came on again today. The car will also stall sometimes while idling. Also, while accelerating, it feels as if the car has zero power. Mileage: 191XXX, New air filter, new fuel injector, new o rings for all injectors, and polished fuel rail/ throttle body. My car has an oil vapor system (No pcv valve). Gets around 20mpg. Thanks for reading! Hopefully somebody can help.

 

[melsg5]

the rattling noise could be a failing timing chain or tensioner, do not continue driving it until you have it checked. If the chain or tensioner completely fail you may cause additional engine damage to the valves.
On the P0304 did you go through all the causes including a compression test?
http://www.obd-codes.com/p0304
If you are sure you dont have an oil leak, than you are burning oil, again a compression test is required

 

[jaypurce]

Thanks for your reply. It is being towed to a mechanic. I'll post an update when I know more, or if the problem is fixed. As for the misfire, I ordered a compression tester online a few days ago, so it should be here any day.

 

[dragonmp5]

Because of the mileage chances are you will have low compression, don't forget to check the coil pack for possibly being the cause of misfire.

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[jaypurce]

The next step will definitely be doing a "swap the coils test" to see if the misfire jumps to a different cylinder (Telling me that the coil is bad) but if it is functional than I will replace the coil pack housing. This is, of course, if the motor isn't shot. My mechanic will be looking at it tomorrow.

 

[Twinpilot001]

Likely a piston cracked?? or - crank/ rods going bad - due to LOW OIL!!!!!!!!!!!These 4 cyl. engines Cannot !! Take any Low oil condition!! Oil pumps gp bad -fail then its engine time!! Thats why they have a "Low oil Sender"!! Yet thatts no reason to not check the oil lever at least weekly!!