X5 bucking like a bronco

[roym01]

...... on second thought. The increase in gas mileage could have been due to the gas I used. I tried filling up with ethanol free 93 instead of my normal 93 with ethanol as I read lots of opinions stating that gas containing ethanol will get you less mileage during cold winter weather.

I'll try swithing back and forth a few times to see if there is something to this.

[PUREVIL]

I have experieced this condition twice. Both times it was below zero degrees outside and I parked my 4.8is in a heated garage. With the car perfectly warm from being indoors it will run poorly and misfire at startup.
I mentioned the condition at the dealership after the SES light came on during the rough idle and was informed it was a MAF sensor fault but the sensor was good.
I was advised to let the engine run for a bit after entering the heated garage so the sensors have time to register the temp change before shutting it down. Apparently this helps somehow.

So far, no more trouble.

[Frozen]

My 2004 4.4i does the same thing in the winter. I park outside and if i let it run for a few minutes it clears up andidles smoothly. Occasionally the CEL will flash but if i cut the ignition and restart it goes away. This has been going on for years now - car has 122000 km's.

[keduMINI]

Originally Posted by roym01

My trusty mechanic, who many consider to be the best indie BMW mechanic in the area, finally had time to see my truck. Told him the symptoms and first thing he asked was 'Does it do it when it is cold?', to which i replied yes, and 'Do you drive it hard?', to which I replied no. First thing he said was 'sounds like water in the intake. If the scan shows multiple cylinder misfires i am pretty sure that's it'.

The solution .............. Blowing out the intake and MAF. Forty five minutes of labour and I was off.

Hate to resurrect an old thread, but a "solution" is provided without much detail.

While this remedy appeared to provide a favorable outcome to the customer, there is not enough information for the DIYer nor service tech to reproduce. Thus, I wonder if the original poster could interview their "indie BMW mechanic" for procedural details and then relay them here? Then this will become a helpful and, better yet, understandable remedy.

[roym01]

Originally Posted by keduMINI

Hate to resurrect an old thread, but a "solution" is provided without much detail.

While this remedy appeared to provide a favorable outcome to the customer, there is not enough information for the DIYer nor service tech to reproduce. Thus, I wonder if the original poster could interview their "indie BMW mechanic" for procedural details and then relay them here? Then this will become a helpful and, better yet, understandable remedy.

I will try to get a more descriptive 'fix' from my mechanic.

[Junkycosmos]

Was there a followup here? I too am wondering if the OP has had long term success or not.

I too run into this but only in specify conditions and only for 15-20 seconds.

My conditions
1. Car parked overnight in heated garage 45f. (It's an old garage so the temp has cycled from 35-45)

2. Outside air temp is between 0-25 F (silly cold)

3. Start the car with the garage door open. Starts great and idles smooth.

4. Put the car in gear and try to back up slowly with foot on brake (no gas pedal use) and I get random misfires.

If I take the car out of gear it smooths out. If I give it gas (to 1500) while in N for 5-10 seconds then try idling in reverse it stays smooth.

Only happens 1 out of 6 days so there is clearly another factor:

Maybe air temp has to be a close range and the sensors are confused by being warm in garage but outside combustion air is way colder?

Maybe related to how hard I drove before parking him night before ?

I am curious on the intermediate levers too however my idle smooths out so quickly.

Junkycosmos
2005 e53 4.8is

[roym01]

Originally Posted by roym01

killcrap, very interesting response and I do appreciate any and all feedback. I am not here to argue or debate, but I think other people with this issue should hear what I have to say.

My mechanic has a reputation of being the best independant BMW mechanic in the GTA (Toronto and surrounding vicinity). A very densely populated region. I found him when I was looking for a used X5 as most of the advice I received included 'find a good indy mechanic' and 'have an honest mechanic due a pre-purchase inspection'. I took to Google and searched for 'best BMW mechanic in GTA' and his name and shop popped up all over the place. He is BMW factory trained, races BMW's and drives a 540. I could only find ONE negative opinion amongst many, many hits. I paid him a visit, chatted a little and came away impressed by him and his shop. Try googling RMP Motors.

He performed the 'fix' while I was standing about 30 feet away. I admit, I did not watch him closely (no reason to) but I did hear him using an air compressor. In about 45 minutes I was out.

I am being completely honest when I say that my X has not run better in the year and a half that I've owned it and has not given me the 'shake' since. I will keep all here posted how my X behaves over the winter.

It's been over a year since my mechanic did his thing. Problem solved. Is it because of the constant -20C temperatures this winter? Maybe, but I would recommend to all with this condition that they gamble $90 before dishing out thousands.