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Discussion Starter · #1 ·
When starting out, the M5 runs really rough for about the first 2 minutes. After it warms up it runs fine, this seems to be getting worse and I am not sure what to tell the dealer. If anyone else is having a similiar problem let me know if you found a solution.

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'00 BMW M5
'00 Westfield Seight
'98 Hummer Wagon
'98 Lexus LS400
'96 Porsche 911 Twin Turbo
'87 Ferrari Testarossa
 

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I have had a similar problem with my 93 325i, 96 M3. This was an "issue" on the boards for those cars. The M5 has run rough for me as well, but I think better than the M3. With the M3, my routine was to start the car then load child and stuff and let the engine warm a minute.

Not saying you have no problem and I hope it is not getting perceptably worse. But it may (I hope) just be a BMW thing. I had some bad moments in my M3 while zipping off from a cold start. It could be quite annoying.

TD
 

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Yeah. It feels to me that there's hesitation at about 1900rpm when it's stone cold. I think this is common. I just try to keep the tach needle at about 1800 rpm (loafing but not lugging -- that would be very bad for a cold engine) until the orange lights on the tach "back off" to 5500. Once they get there, the hesitation goes away.
 

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I took my car to the dealer and complained about that unevenness at low rpm when cold (the car actually bucks when in 1st and 2nd gears). I thought that perhaps the coolant sensor was not working properly and not allowing fuel enrichment when cold. They kept the car overnight and found nothing abnormal. I doubt that they even noticed or, if they did, cared about this "small" a problem. I now have almost 5K miles and, even though it is really warm these days here, I think that the problem is actually getting worse. The software was re-entered from the CD at the dealership. This made no difference. Neither did the Dinan program, as far as this problem is concerned. It is really an annoyance on a car of this quality.
 

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This topic was discussed back last November when the first batch of us (stateside) were getting our cars.

We pretty much determined that this is a universal trait and one of those trade-offs in having a highly tuned 400HP motor.

For just a minute or two, the car will hesitate and run a little rough when completely cold. Afterwards, it's a sweet as can be.

Rick W
 

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No such symptoms here in Florida for obvious resons. How about you Ft. Lauderdale guys?

MJ
'00 Titanium/Black Exclusive FOR SALE
'01 Coming soon
 

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I live just north of Ft. Lauderdale and I'm sorry to say that I'm definitely experiencing the roughness for the first 1-2 minutes while the engine warms.

The dealer said that the car was operating according to specs, and that's the tradeoff for having a racing engine.

The problem that I have is that at 5,000 miles, it continues to get worse :(

Any ideas what I could do?
 

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well, the engine idles a bit higher when you first start up on a cold day... mine idles at about 1000rpm for about a little less than a minute before it goes back down to idling at about 500... the car is extremely jumpy and unpredictable during this time.... but I think that's just the way the car is... you should really warm your car up for a while before you start driving it off.... so I just usually sit in the car for about 2 minutes before I start moving....
 

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Thanks for the advice. I'll try letting the car warm up more before driving it, even though that is contrary to the owner's manual.

I wanted to stress however tha the car is *very* rough before it warms up. In 2nd gear going about 25 MPH it's most noticable... the car lurches forward in fits & starts, until the engine is hot.
 

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Had this issue on my M5. They updated the software and it went away. I am here in Denver and know what cold is (as opposed to you Florida guys where 60 is cooooold) :D

Try it
 

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Interesting this, as I had the same problems associated with my E36 M3. The dealer stripped everything off the top, and re-assembled it, convinced it was an air leak, it was ok for a little while, but has now returned, back to the dealer it went with changes to the Lambda probe etc, and eventually a new throttle switch. It’s not too bad now, but I still have to be careful from cold, as it’s a bit rough, the dealer said the same, that all’s well, and is as BMW intended, it’s a trade off between a highly tuned engine.
I’ve recently changed petrol (make and grade), but that has made no difference to this problem.
 

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I would echo those sentiments. My car has now done 1200 miles (sad story trying to get the service this weekend - main dealer didn't have the correct oils to undertake the work !) and on first start-up it's a bit lumpy for the first couple of miles (prefers to run at 3k than 2k) - smoothness seems to coincide with the fresh-air vents "coming-in".

Me thinks the engine needs to get a certain amount of heat through it before the tolerances and choke are OK.

At least it starts first time, even after the "build-an-ark-now!" weather yesterday
 

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build an arc!, had to wear arm bands to get to the car.
MY car seems to be a bit rough, initially around the 2k rpm mark, normally in 2nd gear, until the temp gauge is on normal (approx 2-4 mins) then all ok.
btw, I also suffered from the fitment of a bad batch of spark plugs, causing missfire etc, apparently this can contribute to the afore mentioned problem, and can be widespread.
 

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ppezaris, I noticed you have an Oxford Green M5 -- do you have any pics to post??

-Chris
 

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Unfortunately I don't have any pictures of my beast yet -- having too much fun driving it to stop & take pictures:)

I'll try to find the time to snap some this week.

I have to say though, with all the Imola-Red-loving that happens on this board, I'm surprised there isn't more chest-thumping about the beautiful Oxford Green / Caramel combination... my beast is *beautiful*.
 

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Green/caramel is an awsum combination. Would have been my choice but we already have 300 ZX TT with that combo.
 

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It is kind of funny, I haven't checked out this board in a while and I see a topic I started over a year ago back up on top! I had to switch user names because I lost my password and my email had changed so I couldn't keep RedM5. My car list has changed a little bit since then also, it was cool to see my old topic again though.

By the way I have never really found a solution and the dealers are pretty much useless around here.

By the way here is the new car list:

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'01 Acura MDX
'01 Lexus LX470
'01 Caterham R500
'00 Acura NSX-T
'00 BMW M5
'00 Westfield Seight
'98 Hummer Wagon
'96 Porsche 911 Twin Turbo
'87 Ferrari Testarossa


All right be honest with me, do I have too many cars?
 

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This is Seasonal

I picked mine up last November, and it ran rough when cold right through early April. No problems after that....until very recently. Now, when our Atlanta mornings have been cooler than 55 degrees, the M5 has started running rough again. I have a short 2.5 mile commute, and the car barely warms up as I turn in my office garage. My solutions have been 1) let the car idle for at least a couple of minutes on the really cold mornings (is this ok for the engine?), 2) open the heat vent slightly to my home garage, 3) drive very cautiously to avoid bucking. Any other hints? To me, these seem to be minor prices to pay for the performance you get as the engine warms, but if this can be fixed, then..............
 
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