Rough idle/start in cold weather?
 

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

possibilities
 

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

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.

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.

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.

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

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.

Follow up Message
 

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. :thumbup:

SM

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

FOLLOW UP
 

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.

All of your symptoms describe a bad oil seperator...Especially about the bad gas mileage. This is what a member lojack said to me about mine

"the blowby and oil that is making its way into the combustion chambers (which is getting past the seperator) causes your engine to run lean and hot, and the computer picks that up and inceases the fuel, which is cold and rich.

After a while your milage will be horrible as the computer dumps more fuel into the chamber to keep from leaning out. I would advise not running it too hard and making sure to keep high octane in the tank until you get this solved."

My car did the exact same thing with the rough start and idle in cold weather...I also blew my valve cover gasket because of this..I'd ask your dealer about your oil seperator...

Added to the list
 

Thanks PrimeTime. I will add oil separator to the list!

Hopefully I'll get more before tomorrow morning!

Another update
 

Apparently, my friends, anything on my list, oil separator, O2 sensors, etc. were all ruled out due to diagnostics and due to the fact that some items were not applicable to my particular engine, manufacture date, etc. The Service Tech guy came out and sat with me to discuss everything.

He said he could try one more thing and that would be to adjust the idle to 'the other setting'. Something like from a .2 to a .8 or something like that? Not sure about my accuracy. Said it would change the throttle response a little, but may help everything.

Now, the car is doing well on cold starts. I am happy. HOWEVER. I was driving in heavy traffic this morning, very slow, speedometer barely registering. The car starts "bucking" along like a horse. Yesterday, the service tech told me there is something called "Slow Creep Buck" or something like that, that they can't pinpoint and don't have a fix for yet.

Either it idles like a Harley when cold, or it bucks like a horse going down the road. These are my options for my nice new, fairly expensive car.

At this point, I'm at a loss here, guys.:banghead:

Jeez..sorry to hear that..I think i noticed a little slow creep buck myself in bumper to bumper highway traffic this morning....

Sid, a couple of questions for you:

1) Do you have the stock exhaust or did you mod it?

2) What brand of gas are you using? And what octane rating?

I had this same issue with my 2004 4.4i. I got it back yesterday from dealer and they updated both the ECU and the TCU (I think) transmission software. Yesterday driving home was very smooth. This morning (16 degrees) the car didn't hesitate and buck when I drove to work. I'm a bit worried tho as they found the oil 1 quart low and that makes me nervous...I had complained about valvetronic ticking when it was cold. With the addition of oil it didn't do that this morning. I don't have the paper work handy but I'll look and see what TSB they mentioned.

No modifications. The exhaust is stock.

I tend to fill up at Chevron stations (that's the card I use) or Exxon and I use thier 93 Octane.

Thoughts, StanF18?

4MoJoe, that would be great if you could get me any information from your paperwork! I would be very appreciative. I think we have updated the TCU software. Not sure about the ECU. What is the ECU? :) Interesting that you had the same problem...

My 2005 4.4 had the same issue, it was so bad that it triggered the check engine light.

They replaced the variable timing motor and its better but still notice some roughness when its really cold.

OK, you're using good gas. I've heard that Chevron is pretty good. Shell is another good one.

I would try a couple of simple things before you start going crazy and spending lots of $$$ on parts. Your problem may be as simple as water condensation in the gas tank and fuel lines, or contaminant build-up, or both.

After you fully finish off your current tank of gas, pour in one treatment of a high-quality fuel injector cleaner right before you fill up again. I use the small Lucas Oil brand bottles.

http://www.lucasoil.com/products/dis...tid=2&loc=show

Use one 5.25 oz bottle per fill-up. The neck of the bottle won't fit into the E53 gas tank, so get a funnel with a narrow stem. Empty the bottle out completely and then fill up as usual. There may be other good brands as well, but this is what one of the guys at Auto Zone recommended and I was not disappointed. Stay away from STP, I've heard their products are not nearly as good. Do this for your next 2 fill-ups and see if the situation improves.

If you're still having a problem, use a high-quality water remover for your 3rd fill-up. I've used Iso-Heet. Same thing, 1 small bottle per tank. I think the isopropyl alcohol products are better than the methanol (regular Heet). This will bind up any excess water in your fuel system and remove it.

I was having a rough idle and engine knocking problem back in November after I possibly got some less than optimal gas. Also, I had just gotten Dinan exhausts, so the sound was amplified even more. But after a couple of tanks of Lucas Oil treatment and one tank of the Iso-Heet, the stuttering is much improved. Once it's fixed, do not to use the Lucas on every fill-up. Every other fill-up is good.

BTW, I read in one of the threads that Chevron's Techron additive is also not bad. You may want to ask around about it.
Also, you may want to replace your fuel filter to prevent the build-up of additional contaminants. My part+labor on that came to $250 at my local dealership. But try the treatments first.

Based on all the guys that responded so far, it looks like the X5 does have a tendency to idle a little rougher in freezing temps. So you might not get it to 100% smoothness for those cold winter starts. But it should not sound like a Harley or a buck like a horse once you've cleaned out your fule system and injectors. That's what worked for me.

Finally, if you're anticipating a super-Arctic super-cold morning, try not to leave your vehicle with an empty tank overnight. Keep it as full as possible to prevent water/ice buildup inside the tank. Of course this is not always possible, but I did read that empty tanks don't do as well in frigid temps. If it's filled with gas, there's no room for the water to creep in.

Good luck!

I found my paper work and this is what they listed: "Customer states upon cold start and when driving the car it bucks and runs very poor check and advise. Checked and found no faults stored in computer. Found TSB relating to customers concerns (tsb dated 12-05-07). Programmed DME and Transmission Control Module."


I'm sure your dealer can look up the TSB on yours and do the DME and TCM programming.

Good luck!

Thanks 4MoJoe! I will definitely ask them. I am scheduled to go back in on Monday.

Thank you again!

Wow, thank you, StanF18! You know, I'd wondered if maybe I got some bad gas or if I needed to consider some kind of treatment in the tank. This is a great plan and I will definitely try it. I am taking it in again next week one last time, but will try this protocol on my own anyway.

When you say "Chevron's Techron additive is also not bad. You may want to ask around about it..." do you mean as an alternative to the lucasoil or as Iso-Heet? Or as an 'every fill up' additive?

Thanks again for all the follow up! Very nice of you! I'll let you know what comes of all this...

Sid

I think Chevron adds a small amount of Techron to their gasoline as is, so you're already getting a little Techron every time you fill up with them. But they also sell a more concentrated bottle than you can add to your tank, for some extra detergent action to get rid of gunk. I meant as an alternative to the Lucas Oil. I would use one or the other, not both. The Iso-Heet is a separate type of product, purely for water removal. By the way, I mis-spoke. It doesn't really "bind" to the water, it just mixes with it (dissolves it) and this new ispopropanol-water mixture will burn up more efficiently in the chamber.

To the OP:

The problem appears to be intermittent, ie you don't have it regularly but more so when cold starting. That is not consistent with a fuel problem, which would tend to remain, particularly if the problem is repeatable and always occurs when the engine is cold.

Chevron gasolines all contain Techron. If you use it regularly it is unlikely that you have dirty injectors, the various grades all contain sufficient Techron to keep the fuel injectors clean. If you have water in the tank, fine, but I wouldn't use a product to remove it more than one time. If you got a bad tank of gas you would likely have burned it up by now. I am a big fan of Techron, and know it from when I used to work at a Chevron fuel distributor. I am suggesting that you proceed cautiously on its use, though.

Your manual contains instructions not to use any fuel additives. After the vehicle is out of warranty, feel free to go ahead. However, using them yourself when the dealer is in the process of diagnosing a rough idle may simply confuse the issue. Your vehicle is under warranty. The dealer has noted the problem. Simply return the vehicle to them and let them do their job. If they can't fix it, find another dealer. It may take more than one trip, and that is unfortunate, but it doesn't mean that they can't methodically work through the list of potential problems until they find it. Suggest you let them do their thing. If the dealer is unable to resolve it after additional visits, you can ask them to bring the regional BMW tech rep in, and meet him at the dealer service department.

Good luck.

We had this exact problem twice with our 01.

First time around: Our regular dealer couldn't figure it out either. Tried a different one, and they got it on the first try. Thermostat and an ignition coil replaced at 35k miles. I believe the coil was replaced in the process of diagnosis (something for your techs to look at for sure), but the culprit was the tstat.

Second time around: Plugged crank vent line/oil-separator clogged.

Please do not assume that the following is the culprit for SidMiller's issues, as the previous threads contain valid root causes, but I do want to add that the VANOS unit could be a culprit, as similar symptoms are experienced in other BMW engines with known bad VANOS units. The nature of VANOS failures do not necessarily generate Fault Codes, which is why this unit is such an illusive failure.

The E36, E39 and E46 have a high level of failure in the VANOS units due to the seals that are used in the units, which do not hold up well to synthetic oil and high temperatures. Why would BMW use correct seals in the X5 engines?

Before someone jumps on me for possible "bad" information or hi-jacking this thread, I am looking at the VANOS as the possible reason for my 2005 X5, 4.4i which is experiencing the following (similar to SidMiller's issues):

1. Bad MPG (<16 MPG highway - easy throttle)
2. Rough Idle (notable at cold start, but present at other times)
3. Poor acceleration under 3000 RPM (always)
4. Valve chatter (sometimes - sounds like clicking)
5. Engine noise from VANOS area (both sides of engine - sounds like a muffled chainsaw)

This all started around 14000 miles, after the dealer changed oil and left it 3 quarts low, which required me to return to the dealer after engine started #4 stated above. They took the car around to the service bay and they returned it shortly stating that nothing was wrong, but the oil "magically" was full.

Unfortunately, the seals that fix the E46 vanos units offered by http://www.beisansystems.com
probably won't fit the V8 VANOS units (N62 bi-VANOS). I want to get similar seals and rebuild the VANOS units on my vehicle and I will provide my findings to this forum.

(ref: BMW X5 Service Manual, p 100-7, Bentley Publishers)

Thank you all
 

My humblest thanks again to StanF18, and now to JCL, vinuneuro, and bimmer! Very nice of you all! This is all great information and all I can say is "the more the better". If I can continue to walk in the door at the dealer and have possible fixes, I am all for it. Everything you guys suggest, I keep and take with me each time. Of course, each suggestion is met with, "...you have a different engine... that would have shown up on the diagnostic... we checked that..." etc. etc. Do we feel that it is 'us against them'? I don't mean to, but it's getting there.

I should clarify: my service advisor and service tech have been very nice and I don't get a bad vibe from them... yet... so I am trying to remain open minded and do what I can to get my car running better.

Also, that idle adjustment they made last week (from a .2 to a .8 - or something like that)? TERRIBLE! The throttle cannot seem to find it's place and I end up bucking down the road or away from stop lights. SO... back to the previous settings.

My plan is to take all these suggestions and any others, and when I go in on Monday, have a new list ready.

Keep em coming, friends, if anyone thinks of anything else. As always, I'll keep posting outcomes and changes in an effort to help anyone else to avoid these same problems.

Sid

Final Outcome
 

Hey friends. My apologies for not posting sooner. Out of town, busy, you know... typical stuff...

Here is my final update:

Last trip to the dealer they returned the idle settings back to a .3 or something like that. They said they made one other small adjustment but didn't give me much detail. They also are sending an entire report of the problem to the New Jersey office and asking that a regional rep look over everything and then plan to check the car when he is in town. Not sure how accurately I am relaying this information, but in short, they have escalated the problem and are looking to the 'higher powers that be' to help us with the issue.

In the meantime, now that the idle has been changed back, there is no more 'bucking' down the road when creaping in traffic, so I am VERY pleased about that. We have only had a few cold mornings here where I could test out the rough start and crazy idle. On those days, I didn't experience the problem at all, which is weird because we are back to all the original settings that we had before when the cold start was such a problem.

Could it be that I really did get some bad gas for a few tanks? I have switched stations for the last couple of fill ups just for the sake of trying something different.

Seriously, all this headache, all of the help from you guys, and it might have been as simple as the gas station/fuel quality? Nah. Tell me it isn't so.

:rolleyes:

Hi guys

Although I hope your problem is resolved please don't let this one die. I have an 01 X5 with the same problem but living in NJ I have a few more cold mornings (9 degrees yesterday). Mine began about a month ago when became really cold. All of the above problems. Please give something I can take to my machanic.

Thanks

BMWguy:

Did you make a list of all of the suggestions everyone gave me? I literally wrote down everything and took the list with me. I basically 'forced' the tech to sit down and give me answers for each potential fix. There are a lot of good suggestions from these guys. They are all very helpful. A couple of guys mentioned their 01's, so maybe that will help you go in a specific direction.

Good luck and keep us posted.

If the problem only occurrs when it's really cold, the problem is certainly the oil-separator.

Sidmiller, Vinuneuro. Thank you I was able to put together a list. I also was able to start the X5 this afternoon (although snowing in NJ) the temps are about 28. It bucked and "stumble" for about 5 minutes then stalled. I restarted it and it ran and idle like nothing was wrong. Again on Monday day morning at 9 degrees it wasn't even attemping to stay running. What else can you tell me about the oil seperator?

I agree this is a great site and have seen me through some tough times, but again my X5 has let me down and I'm driving the E30 in some very bad snowy conditions.

Thanks

Search. It's been covered many many times.

A few degrees below freezing wouldn't qualify as really cold, though, and an oil separator problem doesn't usually show as a stalling/bucking problem first.

I suggest that BMWguy have his mechanic hook up a BMW diagnostic computer and see what the vehicle tells him is wrong, whether fuel, vacuum line, or ignition related. That is certain to be more accurate than our telepathic diagnosis attempts.

That's how it happend for our E53 when we had it and fpr others as well. How many other problems arise only in cold temps? If it's ignition related or there's a vacuum leak, the issue would manifest regardless of temperature. I can't think of any situations that would cause a fuel problems only in cold weather either.

Maybe using the word certainly was a bit too strong, but ruling out other potential causes, and the pattern of cold weather problems with these engines, odds are that his problem is the oil separator.

Yes, it could be related to an oil separator problem. What I picked up on was that when it stalled, it immediately restarted and ran fine. That doesn't sound like a frozen line or valve, it sounds like an electrical problem (or, by extension, a fuel problem relating to an electrical sensor or control).

I stick by my comment that remote control failure analysis is chancy at best ;)

An update. Some how we have to factor in the cold temps. When it is above 35 it starts and runs fine. 2 weeks ago when it wouldn't start at my office I had it flat bedded to my guy and that Monday morning it started and he drove it into the shop. He put the computer on it and it read a number of mis-fired codes. He found a sticking in-take of some kind and a Vanos codes which he dismissed.

I found an article about the vanos on the net and sent it to him. He foward to his BMWTech.com or something like that and the response was that a number of E53 owners had that replaced every winter and although the cold start was better it didn't solve the problem in very cold weather.

Thanks again

Hi, mine had a similar problem but also stalled a couple of times at traffic lights(auto mind you).there is a small intake pipe at the back of the engine (centre, right at the back just at arms reach if your a gibbon)these soften up and collapse then block! bmw advise to replace them every couple of years at about £15 for the part but only on the petrol models.Also check that the plastic expansion tank attached to the underside of the large intake pipe at the front leading into the airbox is not cracked!!!!
GOODLUCK.

Ok guys not much to report but I don't want this to die. I think it is a common problem that we need to get to the bottom of. I was going to take it to my guy this weekend but I didn't want another $500 bill. I ordered the X5 book from Bently. I also was able to start it today with a slight 'stumble" it reached idle and ran fine. I think I'm going to repair stuff I can do. Fuel filter, tubing etc.

I'm open for any updates.

Thanks

Suggest you return to your guy and get him to read the codes, and give you a list of them. That is certain to be cheaper than randomly replacing items that may or may not be the cause. No problem checking around under the hood and looking for loose vacuum lines, etc, but replacing items isn't the same as repairing. Just my $0.02

Thank you, I have a local guy that I work with, together we have been able to locate the little things. The other guy does the big jobs but I think he is stumped. I've decided to wait for the X5 book and do some reading.

Sidmiller please keep me posted. Again this is a great site. It started today witha a slight "stumble" and then ran fine. ??????????

Thanks

SIB
 

Guys I'm sure you've seen this SIB. What are your thoughts?

Thanks

SI B11 08 03
Engine

February 2005
Technical Service

This Service Information bulletin supersedes S.I. B11 08 03 dated December 2003.

[NEW] designates changes to this revision

SUBJECT
Oil Separator - Cold Climate Conditions

MODEL
E39 5 Series, E46 3 Series, and E53 X5 with the M54 Engine

[NEW] SITUATION

Certain areas of the US experience extremely cold climate conditions during the winter months A small number of vehicles in the above series listed have experienced problems ranging from leaking or broken valve covers to complete engine failure.

[NEW] Cause

Moisture accumulating in the engine oil separator, hose to oil dipstick guide tube or the orifice in the dipstick guide tube can freeze. When this occurs, depending on the position of the internal valve, this may either cause high crankcase pressures (stuck closed) resulting in valve cover leakage/breakage or cause an oil hydro-lock condition (stuck open) which could result in engine damage.

[NEW] CORRECTION

In case of a customer complaint, replace the crankcaseventvalve, crankcasevent hose and remove and clean the oil dipstick guide tube orifice.

[NEW] PROCEDURE

Repair/replace all affected components. Access to the oil separator is best achieved by removal of the intake manifold. Refer to Repair Instruction 11 61 050 for details.

1. Replace the oil separator and hoses (1) with the new insulated style (2).

2. The oil separator repair kit fits all the affected models. One additional hose needs to be ordered:

^ (1) E39/E46 PN 11 15 7 532 629

^ (2) 53 PN 11 15 7 532 628

3. Obtain a thin piece of metal measuring approximately:

^ = 2.50 mm

^ = 0.8mm

^ Length = 30 cm

Using a wiper blade metal reinforcement will be sufficient.


4. Remove the oil dipstick guide tube and clean the upper crankcasevent tube orifice using the metal device (1).

Note: The guide tube orifice can be restricted by a build-up of oil, water and ice. Using a brake cleaner solvent will aid in the process.


5. The lower end of the dipstick tube has a double-wall. The outer orifice needs to be cleaned using the metal device (1) as noted above and brake cleaner solvent.

Any update Team? It warmed up enough in New Jersy on Sunday to start the X5 but I now have the SES light and it will not idle. Planning on yet another tow to the shop on Saturday.

Thanks

Well guys here is an update. The following items have been replaced:
Dipstick tube (oil return clog)
Oil Separator/Vacuum Control Vale (internal Diafram torn)
Valvecover breather tube hose (insulated)
Manifold adjust Valve/Disa Valve (just was broken)

Although the temps in New Jersey are about 30, it's been starting and running fine. No temps in the teen's for a real test. Just got it back this weekend. I'll check back at the end of the week.

You have to really keep after them. If you continue to have no joy, I suggest calling BMW Customer Service at 800-831-1117.

I have an 04 545i like delje08 above that has been in the shop for 11 of the 30 weeks since I purchased it (and is still in the shop now - dropped it off Feb 11). I was the one who in essence diagnosed it by finding the N62 intermediate lever SIB posted here.

hi..i just picked up an 04 3.0i on monday and the following day it started to shake like crazy in the morning. It was like 30F here in NJ. The Service engine soon light came on. I took it to denville bmw and they said it was a misfire and took care of it. Light was off and i drove away. following day it started off smooth. Now, no light coming on but started to shake again. I stepped lightly on the gas and suddenly it quiet down. I will call bmw and let them know of this and probably stop by during lunch time since i work next to them. i really hope this is nothing serious..at least they told me before it was not. I guess i'm not the only one after all. I'll also look into all the suggestions that were mentioned in this thread and go from there. Thanks

great thread and very helpful. Subscribed and bump for any updates....

mine just did the same thing E53 2005 4.41
my uncle Who owns a german motors repair shop said its a misfire...off to bmw on monday...will let you know the outcome

This just happened to me, very rough idle and my service engine soon indicator started blinking. WTF??

who is your SA at Denville?

I too experienced the problem earlier today... I will take it bay diagnostic tomorrow. According to the posts, it seems it could either be an oil separator or thermostat?

yeah i'm guessing its the oil separator, it seems like the most common problem

I hope this is CPOd

okay so my SA today said that it cant be the oil separator for my car., but it was due to gas being in the lines and when the car started in the cold air, there was more gas getting pushed through the lines that the engine could not accept.

idk if this makes any sense....

^ lol wut?

so he said it's normal. no fix?

thats what he said. :dunno: its happened to me bad once, if it starts happening more then i'll start complaining.

Rough idle/start only in the morning
 

hi all,

my X5 2001 4.4i is rough on idle during start and only in the morning prior to engine breakdown because of blown piston ring and ignition coil, engine is now overhauled, changed the gaskets, valve cover & spark plugs but after a month it seems that the problem did not go away and now it becomes worse. diagnosed it with GT1 and got two cylinder misfires #1 & #2 as per pic attached. my cluster doesn't show the 'check engine light' although the GT1 says it's on. is this a sign to change the ignition coils? mileage is bad on this car as it has 312xxxkm on it and more problems keep coming, like i just solved the issue with the 'trans failsafe prog' and now here it goes again. temp here in saudi is 13 C in the morning but it's getting rougher day after day.

your inputs will be highly appreciated.

thanks

My Solution
 

FWIW, I had pretty much the exact problem described in the original post: 2005 4.4i about 40K miles, kept in garage, and this past winter (midwest) there were a handful of occassions where immediately on start-up the SUV began to stutter and shake violently until it either died, or I put the car in reverse and started driving. On a few occasions, the Service Engine Soon light came on and I took it to the dealer ... the only error code was something about a fault due to "ambient vehicle environment." At about the same time, I also noticed that the engine was generally idling more roughly than usual and at lower RPMs. Long story short - the dealer replaced the intake manifold ($50 under certified warranty) and the problem vanished. Hope this helps someone else.