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Thread: Car threw huge cloud of smoke on highway

  1. #1
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    Car threw huge cloud of smoke on highway

    Scary event on saturday.

    Getting the car in for service tomorrow. Here are the symptoms/issues:

    a. I was driving on the highway and I noticed a huge cloud of white/gray smoke coming from the rear area. It seemed to go away when I let off the gas but upon acceleration I got the same big amount of smoke.

    b. No issues regarding SES, engine temp, no noises, handling issues, nothing. The engine seemed as strong but (a) was still occuring.

    c. Immediately turned off the road and stopped the engine. Noticed that some oil was dripping from the front passenger air dam area, below the right headlight. About 1/8 - 1/4 cup of oil dripped off and then stopped while the engine cooled and/or the oil pressure in the engine & lines dropped .

    d. I checked the oil and it was pretty much full.

    e. Drove home at low RPM and mostly in 6th and not trying to accelerate. The car did not blow out any more smoke that I could see. The car dripped just a few drops in my garage.

    I am taking it in tomorrow. My belief is that I have a split oil line and the oil dripped onto the headers or catalytic converter during accel and thus threw a lot of smoke. The leak must be small now and works itself out when the oil gets hot and under pressure from somewhere.

    The other (less likely I hope) explanation is that the engine is leaking internally into the cylinders or other internal places and the smoke is coming from the exhaust. That's really not good so I hope it's the leak explanation above. That's why I was happy to see a leak - it would be so easy to fix if it's a line....

    Any thoughts/comments? Did the above happen to anybody?

  2. #2
    Sport Button On - DSC Off Dogsbreath's Avatar
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    Smoke

    Hey

    Are you positive it is oil ? It sounds like it could be antifreeze hitting the manifold. I had this happen to me in my TR3. There was a pinhole in the coolant line and it only leaked when the engine was under load.

    Dave

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    Positive - it's oil.

  4. #4
    Sport Button On - DSC Off Dogsbreath's Avatar
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    Oil

    I hope it's a hose.

    Dave

  5. #5
    Administrator thegunguy's Avatar
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    Well, it was 007's car first...

    ...you must have hit the smoke screen button inadvertently.

    I hope all turns out well.
    thegunguy

  6. #6
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    Air/Oil Separator

    It might just be the Air Oil Separator on the intake. It can be expensive to fix but it just causes smoke and oil with no real damage...

  7. #7
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    I had something similar happen (I was 400 miles from home at the time) it turned out to be a vanos issue. Same symptoms - tons of smoke, and oil pouring out from the front valance region. I did, however, lose a lot of oil.

    The amusing part of this was my first experience of the fabled BMW support. They first of all claimed I'd hit something (this was over the phone), then on inspection they claimed that I was using the wrong oil and this was the cause of the problem (I had put the only oil I could purchase to move the car the 1/2 mile from were I had broken down to the place I was staying). They told me that they'd cleaned it up and replaced the oil and that I was to be billed - I asked them to call me back after they had started it up. They did - rather sheepishly. To cap it all I was then charged for them to valet the car.

    My customer experience with BMW has been less than stellar (and this has been in various locations) - I reported this on several occasions when they phoned for customer feedback. In contrast I have been recently dealing with Ford and found, to my surprise, it's been a real pleasure.

  8. #8
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    The end of an era....

    The era of using Stevens Creek BMW for my service that is. I got a call yesterday after leaving the car in the AM that "well, we were short and could not even see the car today". OK - the manager said he would cover another day for the rental free of charge. I didn't care so....today I get a call and they have the following to tell me:

    a. The smoke was caused by a leaking front shock - the hydraulic oil was evicently leaking and caused the smoke when it hit the hot manifold/exhaust - bushings should be replaced
    b. They saw a leak/stain around in the thermostat - should be replaced
    c. Belts seem worn and should be replaced
    d. Slight leak from a camcover gasket - should be replaced

    The total was compared to an estimate I quickly worked through with Dinan and the verdict was very clearly in Dinan's favor. I got the car back and it will go in on tuesday with Dinan. i think I will now always go there now that my warranty has expired.

    Thanks for the input and funny notes. Although I never heard of a leak in a hydraulic suspension part, that's what they said. Explains the utter lack of any issues with the engine.

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    A question to Biffom

    Your cause is quite close to what I experienced - who knows? it may be that and they missed it during their look over.

    One question: did the SES light come on when this happened to you?

  10. #10
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    Yes it did - I'd completely forgotten about that! It came on and I called BMW (given that it was 400 miles from home). They did the usual "is the fuel cap properly seated" etc... I asked if it was safe to drive it back to Los Angeles - they responded with an affirmative. It was less that 20 miles after I made the call that I broke down.

    As a consequence I'm really particular to locate the source of the problem when the SES light comes on now. I'd been fairly cavalier with it prior to that - a result of too many false alarms.

  11. #11
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    Thanks Biffom - since the SES light did not come on on my car, I guess I'll go with the current diagnostic.

    i know what you mean by the SES causes - I had a bout of these and heard the usual "well, did you forget to lock your gas cap?" ad nauseum. Got the car's M5 engine straightened out and had no issue ever since. I ribbed Steve about this about which is it: Dinan did such a great job with my engine that I no longer have any SES events....or they disconnected it. Just kidding...

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    Problem found....my fault but misdiagnosed by BMW

    It looks like the car will now be fixed right by Dinan. After looking at the issue of the smoke, the people there found that the smoke was actually caused by my putting too much oil into the engine, thereby causing some to be sucked into the intake with the resulting smoke being generated. The intake had to be cleaned along with replacement of the K&N air filters. The oil/filter will also be changed.

    The "leaking" front shock bushings are still in need of replacement but were definitely not the issue. The other suggested repairs except for the manifold gasket which is very slight will also be done.

    BMW-SC therefore did not catch this and the smoke would have come back. The oily air filter and intake would also have probably started an SES event. I guess I'll move on but the fact that they charged me for the diagnosis and did not find the root issue irks me.

    I also need to figure out how I put 1+ quarts to much into that engine. I try to be careful and follow the 15 sec/1 minute rule. Kind of mad at myself. Any other suggestions to read it right?

  13. #13
    Administrator thegunguy's Avatar
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    Please explain 15 sec/1 minute rule

    Quote Originally Posted by siliconvalleyman
    I also need to figure out how I put 1+ quarts to much into that engine. I try to be careful and follow the 15 sec/1 minute rule. Kind of mad at myself. Any other suggestions to read it right?
    I'm glad that Dinan was able to sort out your issue.
    thegunguy

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    Sport Button On - DSC Off Dogsbreath's Avatar
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    Oil Level

    The only thing that comes to mind - are you checking the level when the engine is at operating temp ? I checked the oil level both cold and hot and the difference is about one liter

    Dave

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    15sec/1 min rule

    I don't have the car here, but I remember reading on a tag on the dipstick that the engine should be run for 15 seconds, then one minute after shutdown, the level should be read. My understanding is that the engine should be cold. That's the way I have been reading my oil regularly. Is this wrong?

  16. #16
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    Oil temp

    The engine should be warm when checked. Let Idle, then rest for 1 min or so. This gives the oil a chance to settle back down into the crank case. But I still have a hard time reading the level on the dipstick.

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    Oil Temp

    If that's right - I have been doing it wrong all along. I usually wait for the engine to warm up on my other cars, but I thought I read somewhere in the manual or the dipstick tag to check cold. I will check this when I get the car back & post. Come to think of it, it makes a lot more sense to check warm since that's the state of the engine when it is running. Thanks for the help.

  18. #18
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    Question

    My 2001 z8 is in the dealership right this moment just because of the same problem, so far I have paid $2074.00 and still this problem is not fixed, the car is still in the dealership and doing more tests on the vehicle.
    Last edited by macfly; May 17th 2008 at 01:20.

  19. #19
    Z8 Novice Jeffrey's Avatar
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    Smokin' Z8

    I have the same problem. I decided to get 10W60 this oil change; Tech calls and says car started smoking when they started it. Replaced oil separators but that didn't help. Now they want to replace the driver side Vanos Unit. Please let me know when your problem is solved and I'll do likewise.

  20. #20
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    Oil consumption in the S62 engine used in our Z8s is quite variable. Some owners can go thousands of miles with little to no discernible oil loss while others need to add oil after every spirited drive. These differences are related to engine build date (with earlier motors more prone to burning oil), engine break-in procedure followed when car was new, how hard the engine is run, tolerance differences from one engine to another, mileage on the engine, and type of oil used (no matter what it says in the engine compartment, you should only use Castrol Formula RS 10W-60 synthetic oil). Frequent checking is recommended.

    It is important to remember, however, that an accurate reading of oil level in the S62 motor can only be achieved when the engine is at operating temperature (indicator needle on temp gauge vertical). Measurements taken when the engine is cold will show a deceptively low level of oil (app. 1 quart) which is incorrect. If this reading is used to bring the oil level up to max on the dip stick, the engine's sump will be overfilled and the excess oil can end up in the engine's intake system causing significant smoke from the exhaust and potential damage to the air flow sensors and/or the air filters. In an extreme case, hydraulic lock-up of the engine is possible if enough oil gets into the combustion chambers and this could require a complete engine rebuild. Another significant concern with an overfilled crankcase is frothing of the oil since at its elevated level, it will be in contact with the spinning crankshaft journals leading to aeration of the oil which can starve the engine's bearings of the lubrication they require. Overfilling is not a good thing! It is also important to make sure the car is on a level surface when checking oil level.

    If your Z8's engine does not tend to burn oil, then I suggest checking it every time you fill up the gas tank. That way the engine should be at operating temperature and most gas stations provide a relatively level surface. The correct procedure for checking oil level under these circumstances is to let the engine idle for at least 15 seconds before turning it off. Then wait at least one minute for the oil to drain down into the sump. Now check the oil level with the dipstick (removed, wiped clean, reinserted until it bottoms out, immediately withdrawn). Any reading between the min and max indicators is OK, but if you have Castrol 10W-60 oil with you, topping up the oil level at this time is recommended so that you don't risk running below the min mark before your next gas tank fill-up. (Bavarian Autosport sells a special carrying case #83290144484 that holds one quart of oil and comes with disposable gloves, funnels and wipes, has BMW embroidered on the outside, and looks right at home in the Z8's trunk.) In a pinch, a small amount of a high grade synthetic motor oil can be added but it is not recommended on a regular basis. Never raise the oil level above the max mark. If you do, you should not run the engine at extremely high rpms until you can drain off some of the oil, either by briefly removing the drain plug in the oil pan or using a top-side oil suction device inserted through the dipstick tube (my choice).

    For those whose Z8s burn oil more rapidly or are somewhat anal about maintaining the level at the max mark (that's me), I recommend checking the oil level every time you return home from a drive. That way, the engine is at operating temperature and assuming you have a level surface in your garage, you can just let the engine idle for 15 seconds, then shut it down and wait at least a minute, then check the oil level and top up if necessary from your stash of Castrol 10-60. The nice thing about this regimen is that the next time you want to take your baby out for a spin, you don't have to check the oil because you already know it is correct.

    For reference: smoke caused by oil burned in the engine will appear grey to blue in color while smoke caused by moisture or a coolant leak will appear whitish in color.

    For even more details, see "checking engine oil level" in the engine section of this forum.

  21. #21
    I'm trying to understand why the oil level appears deceptively lower when the engine is cold. If the oil level is correct when the engine is at operating temperature after idling for a short time, what happens thereafter? One might think that as the engine cools down, there might be some further settling of the oil, but apparently one quart of oil is sequestered somewhere away from the oil pan during this cooling process.

  22. #22
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    I, too, am perplexed by this conundrum. I don't know of any other wet sump engine whose oil level decreases when it has cooled down. Logically, you would expect oil that has been providing lubrication and cooling benefits throughout the engine to drain back into the oil pan (the lowest point) when the engine cools down. In the case of the S62, the opposite seems to be the case. I suspect the explanation must lie in the complicated multi-pickup and scavenging pump system incorporated into the motor but I am having a difficult time imagining the mechanism involved. It would be interesting to know what procedure BMW recommends for checking the oil level in their other engines.

  23. #23
    If anyone could explain this it would be S62 maestro Steve Dinan.
    Andrew Macpherson

    Expert Z8 Inspections, with full support for both Z8 sale and purchases.

  24. #24
    I had this same issue this weekend - smoke on acceleration followed by a small leak under the right air intake. What did you find was the solution to your issue? Thanks!

  25. #25
    If there a pressure leak in the valve cover gasket, it could be seeping oil out onto the exhaust manifold, but these motors classically don't blow oil out the back unless there is something wrong, so I'd suggest getting to your trusted tech asap.
    Andrew Macpherson

    Expert Z8 Inspections, with full support for both Z8 sale and purchases.

  26. #26
    Quote Originally Posted by swhit1225 View Post
    I had this same issue this weekend - smoke on acceleration followed by a small leak under the right air intake. What did you find was the solution to your issue? Thanks!
    Hi, there, I had this issue when I bought my Z8. Matt at Peter Pan took it in and diagnosed a failed Cyclone Separator. Valve cover gasket and thrust bushings replaced as well. Oil filter too.
    Good luck,
    Greg
    Greg AH61930 - 2003 - Silver/Black

  27. #27
    That's great info Greg, thanks so much, I hadn't heard about these things before, but we're getting to the age where plastic parts start to fail, so this is great to know!

    I just poked around the web, and tried to learn a bit about these parts. They're basically crankcase/engine oil breather cleaners, and they feed into the air box, here's a diagram showing the parts in our S62.
     
    Andrew Macpherson

    Expert Z8 Inspections, with full support for both Z8 sale and purchases.

  28. #28
    Thanks Greg. Will mention that when I get it in to the shop next week.
    Steve



    Quote Originally Posted by Gregesq View Post
    Hi, there, I had this issue when I bought my Z8. Matt at Peter Pan took it in and diagnosed a failed Cyclone Separator. Valve cover gasket and thrust bushings replaced as well. Oil filter too.
    Good luck,
    Greg

  29. #29
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    Great information- thank you.