# Cold Morning engine rattle-->



## Bill97Z (Dec 20, 2002)

when i start my car in the morning at idle it kind of rattles and sounds like a diesel. If i rev the engine, the noise goes away untill the rpms get back to idle. As soon as I drive a way and it warms up a few minutes the noise is gone....what could it be?


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## The HACK (Dec 19, 2001)

The engine is running TOO rich.

For some reason, there's some residual fuel left in the cylinder or the fuel injectors, and when it first started in the morning the ECU adjusts for the cold temperature and cold start by adjusting the fuel mixture to RICH, but since there's some residual fuel in the cylinder or injector it's causing the engine to sort of choke on an excess of fuel.

At least that's what I think is happening. There might be a small leak in the injectors. If it's doing this on a regular basis, take it to your trusted dealership and have tell them the symptoms, and have them fix whatever is causing it.

Happened to me once when I accidentally pressed the gas pedal before starting the car, the car COUGHED and sputtered for a few seconds, but the sputter went away as soon as I put the car in gear and drove off.


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## Bill97Z (Dec 20, 2002)

Thx for the info. It doesnt really sputter, just a rattle sound like a belt is loose or something, and then it goes away...hmmm.....I will prob bring it in to the dealership soon anyhow and give them one more chance to fix my idle problem before i call up BMW NA.

I have a 2001 manual, and when I come to a stop and push the clutch in, the rpms drop very fast and overshoot the rpm at normal idle, causeing hte car to sputter and almost stall until it gains its rpm's back....annoying and no one can fix it....


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## Guest84 (Dec 21, 2001)

I have the same thing, almost sounds like a waterpump beginning to fail (if you know what that sounds like). Described exactly at Bill did. BMW 330Ci 2001. 23,000 miles.


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## Bill97Z (Dec 20, 2002)

have u brought it to the dealer on this yet?


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## Guest84 (Dec 21, 2001)

Bill97Z said:


> *have u brought it to the dealer on this yet? *


No, gonna wait til the 30k check up (I have 23k on it now), then I will bring it to their attention. Other than an annoying HK sub-woof rattle which just recently began, I can't justify taking it in until required. :dunno: If I do, I'll post a report, and if you would like-wise if you should bring yours in before I. Thanks!


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## Artslinger (Sep 2, 2002)

I mentioned that same exact problem on my last visit to the dealer, rattle noise on cold start-up and sound goes away after 30 seconds. My dealers fix... the infamous "we can not duplicate the problem". The funny thing is my service adviser said his car was doing the same thing and was curious about a cause for this noise.

I also notice that your from a cold climate, this problem does not show up until temps fall down near freezing.


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## Bill97Z (Dec 20, 2002)

oh they will be able to reproduce the problem...even if it means me showing them on a cold morning after the car sat there overnight, and them providing me with a loaner in the mean time!!!


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## Guest84 (Dec 21, 2001)

Artslinger said:


> *I mentioned that same exact problem on my last visit to the dealer, rattle noise on cold start-up and sound goes away after 30 seconds. My dealers fix... the infamous "we can not duplicate the problem". The funny thing is my service adviser said his car was doing the same thing and was curious about a cause for this noise.
> 
> I also notice that your from a cold climate, this problem does not show up until temps fall down near freezing. *


My cold weather "rattle" begins at roughly 45 deg. or colder.


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## neck (Mar 18, 2002)

*same here*

i have the same thing on 325ci... if u have the heat on. it'll be even louder..


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## ChadS (Jan 4, 2002)

Two words: *Secondary Airpump*

I have the same thing on my car and had my dealer look at it. They kept the car overnight and heard it, but could it pin it down to anything. They had a rep from BMWNA coming a few days later so they had me drop the car off the night before and he confirmed that it is just the airpump. The two loaner cars ('02 325i & '01 330i) I had both did the same thing. There is nothing wrong with the car, it just does this in colder weather for about a minute when warming up.


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## Artslinger (Sep 2, 2002)

ChadS said:


> *Two words: Secondary Airpump
> 
> I have the same thing on my car and had my dealer look at it. They kept the car overnight and heard it, but could it pin it down to anything. They had a rep from BMWNA coming a few days later so they had me drop the car off the night before and he confirmed that it is just the airpump. The two loaner cars ('02 325i & '01 330i) I had both did the same thing. There is nothing wrong with the car, it just does this in colder weather for about a minute when warming up. *


Thanks-

I kind of thought it may be something like that... why the heck can't the dealer just tell me the pump makes noise when cold... I can accept that better than "can't duplicate the problem" line of bull.


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## ChadS (Jan 4, 2002)

Artslinger said:


> *Thanks-
> 
> I kind of thought it may be something like that... why the heck can't the dealer just tell me the pump makes noise when cold... I can accept that better than "can't duplicate the problem" line of bull. *


In this case though I really don't think many of the dealers know what the noise is. I know mine didn't until the BMWNA rep came for their routine visit and knew it instantly. I wish they would say though that "we can hear the noise, but we are not sure of the problem and will research with our factory reps". This would be a prefectly acceptable answer for me rather then saying "can't duplicate the problem" which leads me to believe they are just dumb because in this case I can duplicate it every morning. :dunno:

I think this is what Conley on the E65 Roadfly board is going through. His dealer is telling him that we "can't duplicate the problem" (probably because they don't know how to fix it) so he decided to film on tape everything that goes wrong. That puts them in the situation where they can long use "can't duplicate the problem". Pretty smart if you ask me. :thumbup:


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## Bill97Z (Dec 20, 2002)

Thanks for the info, I will let u know what my dealer says just for kicks and grins....


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## Desertnate (Mar 11, 2002)

Ripsnort said:


> *My cold weather "rattle" begins at roughly 45 deg. or colder. *


I have noticed the exact same observations only for me, I don't see it until below freezing. I have also noticed that I only get it when the weather has been very damp/humid as well. On regular cold frost mornings it starts fine, but ocassionionaly after it has snowed/rained and then frozen I get the rough start.

For me it usually goes away after 30 sec or so, and has occured less than 10 times in the 4 years of ownership


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## Gavin Gray (Dec 27, 2001)

*I read somewhere*

that it is the "air pump" for emission reasons. Mine is gravelly and loud at first start up on the morning when it is cold. In warmer weather, I can barely hear it - sounds more like an electric motor.

Contemplating complaining at the dealer, but I feel they will say "they all do that".

Gavin

2002 330i SP, PP, 5-speed


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## bluskye (Jul 24, 2002)

You guys are paranoid. I have that same problem. turn off your radio in the morning and dont move the car, you will notice the rattle sound from the engine goes away with a CLICK coming from the around the glove compartment. Im assuming it's some sort of pump that is turned on during starts, but can be heard in cold starts.


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## low (Jan 2, 2002)

i get this rattle too in the morning...thing is, i live in san diego and my car is garaged..not sure if my garage temperature reaches down anywhere near of those in the east coast..:eeps:


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## Johann (Apr 17, 2002)

My dad and I test drove a brand new 2002 325i this past weekend. From outside the car, it sounded like a diesel right after startup.

I've heard similar cold-starting, diesel-like noises in Golf/Jetta 2.0's.

Jonathan


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## TGD (Aug 7, 2002)

*Secondary Airpump*



ChadS said:


> There is nothing wrong with the car, it just does this in colder weather for about a minute when warming up. [/B]


They warned me about it when I bought the car. But in my warm climate it never lasts for more than 2-3 seconds.


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