Occasional white smoke with rough cold idle
 

My 4.4 2003 X5, 151k miles has occasionally puffed billows of white exhaust, then cleared up. This happened to my wife twice and caused some emergency calls to me to come and get her.

When I got there, the car started, the smoke cleared and it ran fine. She was scared by all the white smoke and thought it would blow up.

Also, I have noticed in colder temps, just starting, the idle is very erratic until the engine warms up. In fact, it hardly runs, surges at idle and needs a lot of throttle correction until it warms up. Anything below around 60 deg is a problem so something is wrong with the enrichment circuit. I would think that points to the ECM.

On the smoke problem, it threw error codes for multiple cylinder misfires, and a load of other downstream catalytic converter problems, then clears up. I thought maybe head gasket or coolant leak would cause white smoke, but the problem clears up and all seems normal. I thought leaky fuel injector, but I figure that is likely one cylinder misfire, not multi cylinder misfires. I was ready to replace the injectors. I have also seen smoke now on startup when it sits overnight, but it clears quickly.

I started to think in might be an ECM problem since cold idle and sporadic smoke could be a fuel injection problem affecting multiple cylinders.

Out of curiosity I made the mistake of trying to clear all the adaptions in the ECM with my scan tool (because the tool would let me do that) and that just about did me in. It stalled, I got engine malfunction errors on the dash, and it hardly ran at all, lost the throttle response all together, lots of smoke, surging idle. I thought next stop was call a tow truck. Finally, after trying that again and shutting down and restarting, at least it is running again and I have throttle response. But the cold idle is still horrible, now maybe worse, until it warms up. And its not really that great when operating temperature, but a least idling around 750 rpm with a slight drift up and down.

Any ideas? I am leaning towards and ECM problem, and thinking of sending it out to have it tested and repaired. Buying a used 17 year old ECM on Ebay doesnt sound very attractive. There is a place that advertises for $200 they can fix an ECM.

But before going that path, thought to check on the forum for any ideas on what else to check. Always good ideas on this forum so asking to share some wisdom about this beast before I go much further on the ECM.

I had a 1989 Camaro 305 small block, with the Tuned Port Injection, FI.

The ECM had an issue where it essentially turned on all the injectors. A very odd failure. I got about 1/4 the mileage, and the engine would 'hunt' at idle and lope. An incredible amount of amount of gas going through.

At no point did I have any white smoke.

White smoke typically from lots of oil consumption, or in some cases, coolant consumption, that is more white steam.

I think the V8s are notorious for valve stem seals so I'm guessing by "white" smoke you mean not black. Clearing adaptations is a good thing but NOT with the engine running. AFAIK, very unlikely that the problem is the DME/ECM so I wouldn't start with that.

80stech is likely on to it, the V8s are notorious for failing VSS, one test would be to start it and let it idle for an extended period of time, something like 10 minutes, like you were waiting in the driveway for tour kid to put on and tie their shoes (mine are slow as molasses [emoji12]) and then give the gas pedal a good poke. Not the end all be all test by any means, but if you get a huge plume of white smoke, it will tell your a lot.

You’ll have guys argue that failing CCV valves can cause this as well, they’re pretty easy to access and a simple check. Pop the CCV caps off and check the orange “gasket” for rips, if they are ripped, replace those first, but I doubt it solves yours problem permanently. (Unfortunately)


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^ agreed with the above. Likely valve cover gaskets, valve stem seals, maybe other vacuum leak.

What codes is it throwing? Not "P" codes, but BMW specific dtc's?

I’m having similar issues, very rough idle on cold startup.
I first noticed the issue after flying cross country to pickup a X5 I bought, being stopped at long red light for the first time, and as I accelerated blue / white smoke out the exhaust. The smoke would only be noticeable when starting from a stop, as the oil would leak then burn on acceleration.
Reading up on this issue I found bad seals would cause that rough idle, especially on cold startup.

From good feedback here on the forum, for my issue it sounded much like worn valve stem seals, which for a DIY mechanic I’d have the engine opened up for a month, and I’m not prepared for such a job . . . not having that kind of free time, plus specialty tools (kits run $800+) which I’d need to find much cheaper on a small budget.

I did check & replace the (easy to access) PCV’s Crankcase Vent Valves . . . passenger side rubber had hairline cracks, but very little carbon buildup. Replaced that side with Bosch (oe) found on eBay @ $25.
The drivers side still looked ok, but I had found a Febi on eBay @ $16, and the curiosity of me always wants to see how an aftermarket holds up -vs- an OE brand.

Since I just bought this X5, I decided to take it to the BMW Stealership for State Inspection . . . plus see what kind of other troubles I purchased.

They advised the blue smoke is likely the Valve Stem Seals, but I could still pass Emissions, which it did. They thankfully advised I could still drive it no problem, but just maintain the oil level. Then the quotes crushed me, $7k to lower the engine from below, clean out the carbon and replace the gaskets and valve stems! $5k to open the engine from above and just replace those valve stem seals.

I explained I was concerned about dumping that much into such an old vehicle which I knew little about it’s history, care by previous owners, etc.
They then suggested a Pressure Test (they would need a whole day to perform) to see if it’s just those seals, or if other issue areas are present.
I didn’t schedule that yet, hesitant as I’m concerned that test might speed up the failure of other seals, or blow out the valve stem seals even more, leading to an insane oil burn rate.

I’d suggest doing the PCV’s, if the smoke still persists, decide for yourself based on how long you’ld like to keep the X5 if the valve stem seal replacement is worth it, because if that’s what it is, it’s not terrible to continue to drive it, just so long as you check the oil level weekly, and carry a funnel and some cheap fully synthetic oil with you at all times, just incase.

I typically swear by Mobile1 0w-40 (one of the last true synthetics) for my bmw’s, but when topping off a engine that’s leaking / burning oil I’m using this Walmart brand as it’s insanely affordable $31 for 12 quarts . . .

https://www.walmart.com/ip/Super-Tec...arts/937402631



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Thanks guys. I will check out seals first. I have been using Mobil 1 0-40W for the past 100,000 miles and the inside of the engine is clean as a whistle. I also had changed valve cover gaskets when I did the valley pan last year. But if VSS are the problem, I MSU just drive it for a while before the next ride...maybe electric ��

I recently had a similar issue with the M54 engine that was a bad CCV.

Not sure if this applies to the V8, but on the M54 while it is running if you try to pull off the oil fill cap and experience a vacuum that will usually indicate a failed CCV.

The vacuum isn't slight either, I had to really work to get the cap off.

Again, take this with a grain of salt though as I'm not sure it applies to the V8.

If it turns out to be the valve stem seals have you looked into what a rebuilt or low mileage motor would cost vs fixing the seals?

The BMW CCV systems, are a real issue, from my experience.

Defeats the whole concept of 'emissions' control, when you always end up sucking oil into the intake like a straw, then burning it.

Or they could have just bit the bullet, and made a vacuum pump to evacuate the crankcase, separate the oil, and feed the harvested air into the intake.

I had an M62tu CCV fail on me on a road trip. #1 cylinder ate the lions share. Had to clean the iridium plugs every 500km.

Didn't trust any local mechanics. Long weekend, middle of the night, car just died on the Hwy. No start....but had my tools.

Also my spare rad, catch can, and water pump with hoses. Just in case.

Yeah, If I have to add 1 quart of cheap oil a month, I’ll deal with that until I decide next spring on either selling it or overhauling the engine myself.
Leaning towards selling, as I’ll continue looking for a 4.8is with 2-tone interior.

Speaking of Electric, just placed my reservation on a VW ID.4 electric RWD suv.
Test drive a Model 3 RWD last month, loved the acceleration but struggled to power slide it, so hope VW didn’t add any of that traction control garbage, or at least gives the option to disengage it, like bmw had.

Update: The white smoke now is significant. I cant drive the car without leaving a cloud behind me so its parked for now. I checked the Crankcase Ventilation Valve (vacuum test from the oil cap) and it must be the CCV after all and not the valve seals. I was curious getting misfires on every cylinder which would make something common to all cylinders more likely than a few Valve Stem Seals starting to deteriorate.

Full vacuum felt with my gloved hand, and this is only supposed to read 4-6" water with a manometer per the manual. I didn't need a manometer to feel the vacuum at the filler cap. It was pretty strong pull. So.. ordering a CCV and gasket.

Next question, I am hoping I can replace the CCV on the back of the intake manifold without removing the intake manifold? I had the intake off last year when I replaced the galley pan (another common N62 issue leaking coolant) and put some nice Felpro intake manifold gaskets on when I re-assembled. I am hoping to just replace the CCV without removing the manifold again if I can avoid it and the extra labor.

Open to comments. Waiting for parts.

No CCV that I know of on the back of the intake (??), one located front of bank 1 and the other front of bank 2 - one on valve cover and the other directly in the CCV pipe, passenger side LHD.


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On the 2003 X5 4.4 it’s on the intake manifold. I ordered one. Seems there are several CCV designs.

Totally missed that, mine is the N62 [emoji106]

Probably still makes sense to check for that light coating of oil in the intake if you’re still seeing smoke.


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You're in Colorado and it's November. Good luck because it will get worse in cold humid air. Choose a nice warm day and take it for a drive where the engine oil gets as hot as possible for a sustained period, like 2 hours, and melts the gummed up oil.

The CCV rarely "breaks", it (and its hoses) get clogged with this oil sludge. Try to put a bottle of olive oil in the fridge and see what happens to the oil. Then put the bottle back on the counter and see the stuff disappear.

If the sludge in your CCV is not 100% sealing off the unit, it will heat up and dissolve on this 2 hour run. And you have just fixed the problem.

White smoke is usually the CCV system blowing oil into the intake manifold. Sometimes it’s the valve stem seals, but that’s expensive so should be looked at last.

Here’s a write up on fixing my problem.

https://xoutpost.com/bmw-sav-forums/...lem-fixed.html

I have been dealing with these issues for about 1 year now. Started with cold rough idle and sometimes white smoke on startup. I also had the alternator bracket leak that you will have if not already. I have replaced cams and eccentric shafts immediate levers to spark plugs to DME and coils. Used parts not new, new would cost 2 3 times what the car is worth.

The valve stem seals go bad in these motors, all of them, meaning v8s.
The job to replace them takes a while and I could prob do it in a weekend in my garage. I have had the heads apart in mine probably 5 times now and I am pretty proficient in it, not to my choice though.

It's cheaper to buy a replacement motor however if you try to get one for our age car it will have the same issues. I looked into getting the newer 4.8 which is doable but there could be some issues with harness and if the motor is out of a car you need to swap the oil pump and oil pan etc.

I removed the cats on mine and tricked to post O2 sensors with a defouler. It runs better but still has same issues.

I am at the point of cutting my losses and selling the car as I don't like throwing money away. I have learned a lot though.

Members feel free to chime in but sometimes the turth hurts. I see these V8s in BMW cars all the time and guess what, they are all smoking white smoke out of the tail pipes. It's a shame that an old chevy would last longer than what is supposed to be an upscale, highly technical engineered machine. Then again the did loose the war for this very reason.

Tonyfeb14, have you smoke tested the engine?

Yep, all N62's will have valve stem seal failure. Alternator gasket will fail (all oil seals fail eventually no matter the cylinder count). Almost all M62's will have timing chain guide failure. The issues with the V8's are well documented, as are the ones with the i6's.

Seen many (definitely not as many as the i6's) of the V8's go over 200k miles. Like any BMW it's all about who owned it before you and how they treated it. I feel for you on your experience, I would have bought another 4.4i and swapped what I wanted before pulling the heads. I certainly applaud your dedication to it, but it seems to have left a sour taste. Comparing an old Chevy to a 20 year old BMW is like comparing a bi-plane to an F15.

LOL yeah I am definitely not the most happy BMW owner and that comparison was me being sarcastic LOL. I have a 1990 300zx TT sitting in my garage and the original seals on it are fine. I also have a 2003 350z with no failures like the BMW. I have never had cars that wear out the valve train components. Don't misunderstand, the X5 is probably the nicest car I have owned and the attention to detail was great. I just think its over engineered. The rubber failing is troublesome and i wonder why their rubber hardens like a rock yet other companies, at least in my experience dont have that issue.

I didn't remove the heads I just replaced the cams and tappets and all the gears etc with a lower mileage unit. The compression and leak down test were fine. I just want the smooth running engine back and the check engine light to go off. Just my OCD I guess.

Tonight I pulled the bumper the replace the ballast on one of the headlights. Not bad but probably not for a person with no knowledge of mechanics.
It's frustrating to not know exactly what part needs to be replaced.

I hear you. But my mom has an Infiniti fx35 with plenty of oil leaks. Oil pan, valve covers were done recently so those don't leak anymore, but they did, rear main is leaking. Rubber wears out. :dunno: Her cats are shot too throwing cel, but still drives fine.

No disagreement on BMW's tendency to over engineer. Makes jobs that would be easy on most cars difficult, or at least more time consuming (like your ballast replacement). Working on my mom's fx is like playing with Legos, though it also required bumper removal for headlights, compared to working on my cars. But I (and my wife) love the way BMWs drive more than other makes. So I deal with being in the garage for a weekend every month or so.

It certainly is frustrating at times, especially in a case like yours where the actual diagnosis of the problem is elusive. Fingers crossed that you figure it out soon.

So, just to close out this thread. The smoking turned out to be the crankcase ventilation (CCV). Thanks to this thread I did chase it down to a torn diaphragm in the CCV. Replacing it all this week and I expect the cold idle issue, the smoke, the CEL codes to all clear clear up. The valve stem seals are unlikely the issue as I found out I have an M62 TU and not an N62 which seems to have valve stem issues. The CCV explains why I was getting misfires on multiple cylinders and not just one or two like a bad seal might cause. When I pulled the intake manifold, all the intake ports were soaked with oil, so this mess of oil was the whole problem.