Rough idle/start in cold weather?

[sidmiller]

I have a 2005 X5 4.4 (Sport, Cold Weather Pkg., etc.) that I purchased about 6 months ago. Now that the cold weather is setting in a bit, I am noticing a very rough start and rough idle when first starting the engine each day. Before the cold weather, I noticed that sometimes the car seemed to hesitate or act like it was misfiring when the engine was cold, but now it seems much worse. Dealership says, "BMW's run rich when they are cold and everyone complains about it." This just doesn't seem right to me. As an example, when the engine is cold, I can keep in the car in Park, gently press the gas pedal to increase the RPM's very slightly, and the car will shake and chug like it wants to stall. But if I continue to press the gas pedal further , it seems okay. EVERY time I take it to the dealership, I cannot replicate the problem, so there is no help there.

Also, gas mileage is much lower than expected in this car. 13-14 mpg in town and barely 18 highway. I have a rack on top for the bikes, so a slight drop in mileage is to be expected, but this much?

Thoughts, ideas? Is this a typical BMW trait when they are cold?

Thanks, friends! It's makin' me crazy!

SM

[tonydan1]

Hi,

I had the same issue. it was a small leak in the intake manifold. brought it to bmw and they solved the issue. if not, replace oil with 0w30 castrol, add iridium spark plugs and add a very good fuel injector cleaner. a new air filter wouldn't hurt either.

these are solutions at a smal ccost and under 200$, if you do it yourself.

let me know

[JCL]

Not a typical trait IMO. Leave it at the dealer overnight so that they have it when it is cold. If they can't find anything, try another dealer.

Suggest you don't start the DIY fixes suggested above until you have exhausted all dealer channels, especially considering you have two more years of warranty left.

Good luck.

[klnteg]

Check the colour of your spark plugs. That will give you an indication how the motor is running. How many kms on the X? might be an air leak somewhere as mentioned above. take a can of WD-40 or a similar alcohol based solvant and spray at the intake monifold and hoses around it, while the car is running. If it fluxuates in idle you have a leak at that spot.

[hvisser4]

I agree that it should not be normal, but my 2005 4.8is does the same.

If the temperature has been below 5 Deg Celsius overnight, on startup at idle it chugs like it wants to stall and shakes the whole car from side to side. Sometimes the Engine Management light comes on for a few seconds as well (flashes on and of for about 5sec then solid for about 10sec). If on startup I bring the revs up a bit to 2000RPM or so, for about 15-30 seconds it does not do this.

Had it to the dealer at least 3 times but they can't replicate it either, that said, they've never had it overnight and every time they looked at it almost right away so the engine would still have been warm. One of the times they said a misfire registered in the computer, but it was nothing to worry about. I am not convinced though.

[delje08]

I had the same issue with my 04 545i. We have the same engine. I attached a SIB concerning this issue.

[Hallatauer]

16F this morning and started smooth and ran smoothly. Only thing I notice is when the engine is cold, a minor loss of power which returns once the engine gets to operating temperature.

Sounds like your dealer is too lazy to look for a problem on their dollar.

[sidmiller]

Hey, all you guys are great! Thanks so much for all the input and ideas. Here is an update:

It was 20 degrees overnight here, so I secretly left the car at the dealer yesterday evening and showed up unannounced this morning requesting they sit with me when I start the car after sitting all night. It worked like a charm. Two technicians stood outside the car, I started it, waited, gently pressed the gas pedal and "The Jalopy Syndrome" kicked in. Sounded like an old Model T or something. Their response was, "Ohhh! Okay!"

I mentioned to them some of the issues you guys were having and what remedies you found. They nodded and said, "Could be that, we'll have to check. Might be software. Might be intake manifold." Etc. Etc. But it was like a light went on in their heads.

Appointment on the 8th of January to check this and a few other things. I have a full list of SIB's, remedies, suggestions, etc., as well as some of your responses saying your cars didn't have this problem in colder temperatures - all in a bulleted Word Document titled RESEARCH. Hopefully they'll see I'm not going to go away!

Again thanks to you all! I WILL update after the appointment.

SM

[Boston X5 4.4]

Good follow-up
Hope it all works out for you.

[sidmiller]

Hey Friends, here is an update on the outcome:

The dealer kept my X5 for a couple of days. When I got the call that it was ready, they told me everything they had worked on. Everything ELSE that was on my list. So I asked about the rough idle, and their response was, "Oh, let me check and see what we found out." Turns out, they upgraded the software. Okay... nice enough offer... but seems to be the easiest solution. So I said I'd drive it for a few days and see if it was any better at cold starts. At first, everything seemed great. Smoother shifting, better gas mileage, smoother starts, etc. I was actually pleased and almost dropped you guys a note to tell you. HOWEVER...

Yesterday morning, 30F degrees out. Started the car, and "The Jalopy Syndrome" was back and as strong as ever. Shaking back and forth, sounding like a Harley Davidson motorcycle but not as loud.

I am taking it back in tomorrow morning. Apparently, the SIB, the suggestions from you guys, the print out I gave them didn't seem to help. They went with the easy way out. I would like to ask if you guys have any more thoughts, shoot them to me. I'll bombard these guys with suggestions and tell them to keep the car until they have fixed it!

Thanks again, friends.