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bad idling

12K views 14 replies 7 participants last post by  apr4176 
#1 ·
hello. im having an e46 318i 2000 model. it starts just perfectly.the problem is that ; the idling is bad, as it idles i can see the rev count moving up and down around 500 and 1000. i bought a new starter,a new coil, a new set of HT cable.i bought a new pick up sensor.
as i try to press the accelerator,the revs take too long to pick up....so please.
 
#2 ·
Hi Vusa

We had the same problem (in New Zealand) with our 2003 318i (4 cyl). Car started fine in the mornings but once warmed up would idle erratically at every stop sign or traffic light. We checked the vacuum lines and all electrics but to no avail. The problem went away when we replaced the fuel filter. Shouldn't cost more than about R150 - R200. I think what happens is that the electronics automatically feed the engine with more fuel at startup but when the engine has reached operating temperature the fuel pump struggles at low revs to get the fuel through the clogged up fuel filter. Hence poor idling (hunting up and down) and poor acceleration from standstill and poor fuel economy. Good luck.
 
#3 ·
hello chris,i was on a festive and guess what i did.i bought a new fuel filter but its stil the same.the idling is stil hunting(up and down). i bought a new air flow sensor stil nothing...please help. i see u mentioned te vaccum system,how do i check it? please help,i stil love my 318i ,i dont wanna scrap it yet..
 
#4 ·
Hi there, I've experienced almost exactly the same problems with my 318i (2002 Auto - 4 cyl - 80 000k's). I think the 318 never made it to the USA so you won't find many posts or help on your problem. I am not a mechanic so I bought the Haynes Manual for the BMW 3-Series (published in the UK). At page REF.13 it gives the following as possible causes for Engine Idles Erratically, Engine misfires at Idle Speed, Engine stalls and Engine lacks Power: The common denominators are:

Air filter element clogged
Air in fuel system
Vacuum leak at throttle body, inlet manifold or hoses
Timing chain incorrectly fitted or tensioned
Faulty fuel injectors
Disconnected, leaking or perished crankcase ventilation hoses
Fuel filter choked
Fuel pump faulty or delivery pressure low
Fuel tank vent blocked or fuel pipes restricted
Brakes binding

Most of these you can check yourself. In my case, I eliminated them one by one. I had vacuum leaks and replaced the hoses. No change. I replaced the fuel filter and replaced the seals in the vacuum pump and the problems all went away, including the oil leak at the back of the engine that caused the burning oil smell when the car had wormed up.

My theory - untested - is that the leaking (brake) vacuum pump caused the brakes to "bind" at idling when the car had warmed to operating temperature. The idling rev's then dropped to about 500 before the engine's electronic management system kicked in and raised it to about 700 or 800, before the whole process repeated itself. There is a link somewhere on this site on how to recondition your vacuum pump cheaply (less than R200 or so). A clogged fuel filter would cause the engine to behave the same way. As I said, my problems went away when I replaced both items.

I would suggest you check all the hoses for obvious leaks. If you don't find cracks or loose fittings, I would suggest asking a BMW service to check the vacuum. They have a small hand-held device and the test takes only a minute or two.

Is your fuel pump okay? Have you checked all the other items that may be the cause? There is a good deal of pleasure to be had working on your own car (without being too adventurous, I suggest). When all else fails it's got to be the timing chain.

Hope this helps.

Chris M
 
#5 ·
Hello Chris, thanx so much for the effort you are putting to help me. im not a mechanic too but i have a feeling that since im in the enginnering field i will eventuall get to the root cause...i really dont know where the vaccum pump is,i would love to check it too. i tested the fuel pump and its pumping pressure of just above 3.5 Bars..i bought a complete minor service kit ie: spark plugs,air filter,fuel filter,oil filter and oil.
i have checked if the fuel is getting to the injectors and for sure it does. how do i check the injectors themselves, how can i check the vaccum system/ vaccum throttle body.
im in botswana Chris,where can i get that manual you spoke about.? you can contact me directly at 00267( 74025476) or (00267) 6214385 or vusapaulos@gmail.com. if you dont mind you can send me your contacts and i will contact you myself...please,thanx for your patiance its highly appreciated.
 
#10 ·
Hello Chris, thanx so much for the effort you are putting to help me. im not a mechanic too but i have a feeling that since im in the enginnering field i will eventuall get to the root cause...i really dont know where the vaccum pump is,i would love to check it too. i tested the fuel pump and its pumping pressure of just above 3.5 Bars..i bought a complete minor service kit ie: spark plugs,air filter,fuel filter,oil filter and oil.
i have checked if the fuel is getting to the injectors and for sure it does. how do i check the injectors themselves, how can i check the vaccum system/ vaccum throttle body.
im in botswana Chris,where can i get that manual you spoke about.? you can contact me directly at 00267( 74025476) or (00267) 6214385 or vusapaulos@gmail.com. if you dont mind you can send me your contacts and i will contact you myself...please,thanx for your patiance its highly appreciated.
Whereabout in Botswana do you stay, myself am in Francistown. With mine its an annoying sound coming from around the belts area which gets more pronounced when i press the clutch. its a 318i aswell

http://forum.e46fanatics.com/showpost.php?p=15040669&postcount=17
 
#6 ·
Howzat Vusa!!
How things that side of the world? I been a few times to Gabs and love Bots.
Have you searched the internet for any clues? I have a 323 and not really familiar with the 318. But i would think in terms of a vacuum leak as well. I will see what i can dig up on the net. Chris has also outlined most of the probable causes as well.
 
#7 ·
Hi Vusa,

You can get the book from www.haynes.co.uk by ordering online or get it through your local bookshop. The book details are as follows: Haynes Service and Repair Manual, BMW 3-Series Sept 1998 to 2003 - Petrol. The ISBN number which is essential for ordering from your bookshop is ISBN 1 84425 067 9. The models covered by the book are the E46 BMW 3 Series with 4 and 6 cylinder petrol engines, which include the 316i, 318i, 323i, 325i, 328i and 330i. In the 4 cylinder models the 1.8 litre (1796cc), 1.9 litre (1895cc) and 2.0 litre (1995cc) engines are covered, including Valvetronic engines.

I have the 2.0 litre model.

With your engineering background most of the tasks and jobs in the book should be within your reach.

I wish you a happy, safe and prosperous 2013 and many kilometres of enjoyable driving in your BM.

And yes, Rod is right. You live in a beautiful country. I spent a year living in a tented camp near Maun when I was a boy and it was paradise. I remember all too well frogs as big as chickens - and tasting quite sweet! My heart belongs to that part of Africa. If they find a snake here in New Zealand it gets onto the national news. My wife laughed at me last week when I called her to come out to look at a Cape Turtle Dove - probably an unwelcome immigrant like me.

Chris M
 
#8 ·
So Chris, u from RSA originally or what? I was there in the late 90's for work and was smitten with the place. Gabarone was just this vibrant city. I tried for years too get a job over there but no luck.
Whereabouts in NZ are you from? NZ was actually my first port of call but i couldnt get a job there from RSA so i came to Aus instead.

Vusa keep pushing ahead with the beemer, they are great cars!!
 
#15 ·
Bad Idle.....



Check your idle control valve. Take of your air intake and all hoses down to the throttle. It should sit next to the throttle body. Disconnect the cable and remove it. Shake it back and forth, if you do not hear a clacking type sound, then it's more than likely clogged. Spray some mass air flow cleaner/seafoam in it and clean it out. Also clean the throttle body. Put a rag in it, do not want anything going inside. I highly recommend doing this before spending money on fuel filters and other stuff. The main thing though is always use QUALITY high octane gas. The cheap gas, even though it's high octane from these no name places is really bad on our bimmers.

Robert
 
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