QuestionThank you so much for your expert advice. It is very helpful. First of all, i actually made a mistake in the original question: "while the mph meter shoots to the high side" should be the mpg meter.
The current situation of the car now has worsened a little bit more - it can't be started at all. Though the starter (ignition) does fire (cranking sounds so battery is fine) but the car can't start. Just as you said, we are focusing on Air Flow Meter (AFM) and Idle Control Valve (ICV) now. But since the car just fails to start now, we are also suspecting the fuel pump being dead. Is it reasonable to think so?
Thanks again for your great help!!!
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The text above is a follow-up to ...
-----Question-----
It begins to happen lately that when the car is stopped (say at traffic lights). The symptom is a collection of:
1. Engine gets slightly shaking and can stall sometimes
2. Sometimes the rev meter (normal at about 600 rev when car is stopped) comes down a little while the mph meter shoots to the high side, likely the system is erratically pumping extra oil.
3. Lately it starts to take longer than before for the engine to start when the key is turned.
The engine never stall when car is running on the road. The problem only comes up when car is nearly stopping or at P or N position (or D with foot brake down). Air filter, engine oil, oil filter, ignition plugs are all brand new.
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Frank,
600rpm is pretty low for a 325i to idle at. These cars arent' carburetted, so you cant really adjust idle on them manually (you can, but it's not the right way to fix this). Something electronic is malfunctioning. It could be the Air Flow Meter (AFM), Idle Control Valve (ICV) or a few other items.
Your best bet is to clean the ICV. If you open the hood and stand on the driver's side of the engine. Follow the intake system from the air filter up to the engine. On the large black intake boot that connects to the engine there is a little cylinder that connects to this intake boot. The ICV is about the size of a salt shaker (best I could do!) with a connector in the end. It's very simple to remove as well. Once you have it off, spray some starting fluid liberally inside this ICV. You will notice alot of gunk running out. This will definately make the engine run better.
Good luck,
Josh
AnswerFrank,
I realize you are no mechanic, but I wanted to correct you on something. You mentioned the starter not working, and then put "ignition" in parenthesis. The ignition system is separate from the starter all together. The starter is an electric motor that spins the engine. Like in the old movies you saw a guy put a lever in the front of a car and push it quickly... that's what a starter does. The ignition system is the spark plugs and all the components of the system to "ignite" the fuel.
Yes you are correct to suspect the fuel pump. There are 2 major things an engine needs to run; Fuel and Spark! Check your plugs for spark. If you have none, then thats at least part of your problem. Then check for fuel.. if you have none then again, this is your problem. Once you know what part you are missing, the hard part comes... figuring out why its not working.
Good luck,
Josh
