# Light blue smoke from the tailpipe??



## dtkw (Sep 1, 2003)

As the title, what does it mean? Too lean? Too rich? Wife says smell like cooling...any idea what is going on? Any reply will be appreciated. Car is 97 740iL.


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## crewdog843 (Mar 15, 2006)

Light blue smoke from the tailpipe is a sign of burning oil. If indeed it is oil, it will hang in the air and not dissipate for some time. If it appears at startup, and then stops, it is a sign of a leaking valve seal. If it continues while driving, it is a sign of a broken ring. 

Whitish smoke at startup on a warm day is a sign of possible head gasket damage or a cracked head. Water/coolant is being burnt along with fuel. It might smell sweet, and it might be accompanied by drops of water from the tail pipe.

Dark colored smoke means either you are driving a diesel, or your air/fuel mix is too heavy on the fuel side. Will also smell sweet. Your car could run rough.

Before it is too late, check your oil and make sure no water is mixing with it. Keep an eye on the oil....water in the oil will look like a dirty chocolate milkshake. Do not drive the car, seek professional help. 

Is the car running rough?

jake


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## dtkw (Sep 1, 2003)

Yeah, I am going to have it tow to the dealer to check it. The indy mechanic in town is crooked.


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## crewdog843 (Mar 15, 2006)

If their diagnosis seems too high in terms of price, it might just be. You may want to get a second opinion. Do you have an aftermarket warranty?

jake


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## dtkw (Sep 1, 2003)

No, the car is ten years old and couldn't find any place to get outside repair insurance for it.


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## nuttybgc (Mar 14, 2008)

crewdog843 said:


> Whitish smoke at startup on a warm day is a sign of possible head gasket damage or a cracked head. Water/coolant is being burnt along with fuel. It might smell sweet, and it might be accompanied by drops of water from the tail pipe.
> 
> Dark colored smoke means either you are driving a diesel, or your air/fuel mix is too heavy on the fuel side. Will also smell sweet. Your car could run rough.
> 
> ...


Okay I'm really nervous about the symptoms of my 98 E38. I really need some suggestions. My car on every start up will give out a big white/grey smoke but there really isn't an odor and will go away after about 10-20 seconds when the car is on the move. Then I noticed the car starting to shake now. As described above I checked the engine oil and it does kind of look like there is water mixed with oil. I'm afraid of turning on the engine now for it may be something big that will mess up my engine. What can be causing this? Am I too late or can I still get this fix without any major damage done to my engine? Thanks for any advice in advance!


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## nuttybgc (Mar 14, 2008)

Any suggestions??? I really need some input on my situation please... "Sigh". I'm afraid I can't drive the car for an inspection now. I'm a new BMW owner and my car is really driving me nuts!!! I like the design of the car but the quality is really getting on my nerves. Something always seem to come up after another.


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## TerryY (Jul 20, 2003)

Are you running synthetic oil? What viscosity?

It sounds like the oil separator and the non return valve need to be checked. Smoke Cloud on start up is a sign of puddled oil being sucked up at the start. Could also be valve guides but they also cause puffs while starting off from traffic lights and such.

Shaking at idle is a sign of a vacuum leak.


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## nuttybgc (Mar 14, 2008)

TerryY said:


> Are you running synthetic oil? What viscosity?
> 
> It sounds like the oil separator and the non return valve need to be checked. Smoke Cloud on start up is a sign of puddled oil being sucked up at the start. Could also be valve guides but they also cause puffs while starting off from traffic lights and such.
> 
> Shaking at idle is a sign of a vacuum leak.


I'm running on the recommended BMW synthetic oil. What do you mean by viscosity, please excuse my lack of knowledge. Anyways thanks for taking your time to read this, I really appreciate your help. So does that mean my engine is still okay because I was afraid my engine went out on me and might have to get a new engine. Do you know where I can find the write ups for DIY.


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## TerryY (Jul 20, 2003)

My M60 740 puddled oil in the intake manifold when it was shut off. A restart sucked it up and made a cloud of faint blue smoke.

Using a heavier oil than recommended -Mobile 1 15/50 in my case made it smoke less.

http://www.e38.org/ has more info than I could give.


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## nuttybgc (Mar 14, 2008)

Do my symptoms mean it's not a cracked head or head gasket problem?


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## TerryY (Jul 20, 2003)

Condensation will leave a little bit of water in the oil--especially after short trips. Coolant in the oil loosks lik either a milk shake or mayonnaise depending on who is describing it.

Are you losing any coolant?

The oil level slowly going down is the smoke you see. If the motor isn't making strange noises the oil separator or the non return valve in the back of the intake manifold could be your problem. Check the separator and its 3 hoses first. Should be attached to the engine just to the left of the water pump.


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## nuttybgc (Mar 14, 2008)

This is how much I know when this happened to me and I haven't turn the car on since then. I'm not losing any coolant. It's not making any noises. But has a shake that I noticed in the car on my way back home and there was a smell that I noticed while I was inside the car when this all happened while I was driving the car. When you say the "oil separator" is that the "osv". Is it also known as the "rear intake manifold cover"?


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## nuttybgc (Mar 14, 2008)

I just checked and there's oil all in the space where the spark plugs are. What can be causing oil to get in there?


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## TerryY (Jul 20, 2003)

Leaky valve cover gaskets will let oil pool around the spark plugs. It will miss pretty bad if it gets deep enough. The coils are sealed but the spark plug connectors need to be cleaned.


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## nuttybgc (Mar 14, 2008)

TerryY said:


> Leaky valve cover gaskets will let oil pool around the spark plugs. It will miss pretty bad if it gets deep enough. The coils are sealed but the spark plug connectors need to be cleaned.


Does the leaky valve cover gaskets make the car have a rough shake/idle??? Also when I took out the dipstick it was making a sucking noise and was sucking in my finger. It's almost as if the car was going to die, so I'm guessing I have an "osv" problem along with the "valve cover gaskets" leak. If the "osv" is failing then can it be because of that that there is 4 or 5 drips of oil everyday on the garage floor? About the "valley pan" how does one know if something is wrong with the "valley pan"???


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## crewdog843 (Mar 15, 2006)

On the '01, the OSV is located at the rear of the engine at the top...you can see it if you take the acoustic cover off. On the '98, I am not sure where exactly itis, as earlier models have a different OSV. Deterioration of the diaphragm inside the OSV will cause the smoke, the sucking sound at the dipstick (some describe it as a 'howling noise'), the excessive vacuum inside the engine (lean condition). If you take your car to a competent independent BMW shop, or even to a dealer, they will diagnose the problem by one of several methods. The fix generally involves taking the intake manifold off the engine and replacing the OSV (they don't just go and break the part off like several on other forums have suggested and replacing it with a new OSV). When they have the intake manifold off, they can spot signs off valley pan gasket deterioration (you might even be able to spot it yourself by using a strong flashlight and shining it down through the intake manifold....look for dried coolant along the edges of the cover....green or greenish blue, or even blue).

You should not have any moisture in the oil. If the engine oil does not look like just oil (either yellow if clean, brown (moderate mileage between oil changes) or black (too long between oil changes)...you have spotted the beginning of a BIG problem. My suggestion, post a picture of what your oil looks like now and let us see what you see....verbal descriptions don't do it justice). Your oil should not look like dirty mayonnaise or a dirty milkshake. If it does, you may have a cracked head which needs to be addressed quickly.

jake


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## nuttybgc (Mar 14, 2008)

Here are some pictures of the motor oil from my car that I just took right now. Tell me what you do you think it looks like because I'm not sure myself.


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## crewdog843 (Mar 15, 2006)

Your oil looks just moderately dirty....I don't see any water which would separate from the oil and leave a bit of a halo on the napkin. Question: Did you run the engine and let it warm up before using the dipstick, or did you just take the dipstick out and allow the oil to drip off? Here's an even better test: Take a picture of the inside of the oil filler cap, with the engine cooled down....if there is water in the oil, the underside of the filler cap will have a milky appearance.

If there is still lingering doubt in your mind: Drain and replace your oil and filter...do it yourself if you know how (it's quite easy). Use a good quality 5W-30 synthetic...your dealer is quite competitive as far as pricing goes....use BMW's oil filter, as it comes with a new reservoir washer and also a new crush washer for the oil pan. Your car should take about 7.5 quarts. Castrol is a high quality oil to use.

jake


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## nuttybgc (Mar 14, 2008)

No, the car hasn't been started up today at all. I just took the dipstick out and let the oil drip. There doesn't seem to be any milky appearance in the oil filler cap either. I guess it's just me tripping out on the oil. But it certainly appears to have green/blue leak around the intake manifold. Where exactly is the "oil separator" located at? Is it located to the left of the water pump? I think I may have to replace the "valley pan", the "rear intake manifold cover", the "oil separator" and the "valve cover gaskets". Because I checked those areas and there seem to be leaks around those areas although everytime I check my engine oil is full and my coolant is full. This has been going on for about 5-6 months now. There's an oil leak somewhere but it's very little and make only 4-5 drips everyday. The passenger side front middle part of the engine is covered with oil though and now the area where the oil pan is underneath the car is covered with oil. Where can this leak be coming from if my engine oil is always full. I'm starting to think it's the transmission oil because the oil looks reddish and not yellow or brown or black. But when I check the transmission I can't find any leak.


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