black smoke

[calh4289]

Three comments/looking for opinions: 99 996 c2 CPO

1. I recently got my oil changed. The following day a friend said that I was blowing black smoke out of my exhaust when I shifted gears. I have never seen this problem in the past and I am assuming that it was just because the oil was topped off.

2. There seems to be a loud rattle only when I start up the car. I think that it is coming from the muffler area.

3. When I start the car for the first time of the day i generally have to let the car warm up before I take off. Otherwise the car wants to die when I give it gas (almost like it is flooded).

Any comments/suggestions would be greatly appreciated. I will be bringing the car in sooner or later since its still under warranty.

Jarrod

[djantlive]

Leaky injectors? How is your idle? Compression done on engine may be needed. Are you losing oil between oil changes? Are you plugs over 30k? If so, change them.

[calh4289]

the car has 52,000 miles, it goes through about 1 qt per 1200 miles. Idle is fine, but sometimes it flutters around 1000rpm. I bought the car with 43K and it had just had the minor servicing.

thanks for the quick reply.

jarrod

[1999Porsche911]

1 quart per 1200 miles???? No wonder the previous owner sold it. Check the PCV system and make sure it is not blocked. Otherwise, if you are not leaking oil, that is alot of oil to be pumping through the combustion chamber. That's like adding 1 1/2 cups of oil to the gas tank everytime you fill up. So, if you are in fact burning that much oil, you will occasionally see it being blown out of the tailpipes when accelerated hard.

[calh4289]

1 quart per 1200 miles????  No wonder the previous owner sold it.  Check the PCV system and make sure it is not blocked.  Otherwise, if you are not leaking oil, that is alot of oil to be pumping through the combustion chamber.  That's like adding 1 1/2 cups of oil to the gas tank everytime you fill up.  So, if you are in fact burning that much oil, you will occasionally see it being blown out of the tailpipes when accelerated hard.

<{POST_SNAPBACK}>

I do see oil coming out of the tailpipes....when the car sits and idles to warm up it always has a little oil in the puddle.. would you please elaborate on what I should be looking for/at in the PCV system?

Jarrod

[1999Porsche911]

Jarrod:

Is the car (for the most part) driven easily? You may try driving it hard (redline) regularly and see if forcing the piston rings against the cylinder walls will help seal them better. (if that is contributing to the oil burning)

[calh4289]

Jarrod:

Is the car (for the most part) driven easily?  You may try driving it hard (redline) regularly and see if forcing the piston rings against the cylinder walls will help seal them better.  (if that is contributing to the oil burning)

<{POST_SNAPBACK}>

Around town the car is driven easy, but it is regularly driven for 30 minute periods on the interstate to work. I normally like to get on it while merging into traffic....otherwise regular rpms are in the 3000 range while cruising.

Jarrod

[1999Porsche911]

I would suggest taking the car up to redline often. It doesn't have to be in every gear, but when getting ion the highway, there is no reason you cannot redline it in 1st and 2nd gear. The pressure in the cylinders at these high RPM's is needed to help maintain clean cylinder walls. As the pressure increases, it forces the rings to expand (open) to their maximum ability and scrape the cylinder walls firmly. You may find that after doing this regularly, your oil consumption will decrease.

[calh4289]

I would suggest taking the car up to redline often.  It doesn't have to be in every gear, but when getting ion the highway, there is no reason you cannot redline it in 1st and 2nd gear.  The pressure in the cylinders at these high RPM's is needed to help maintain clean cylinder walls.  As the pressure increases, it forces the rings to expand (open) to their maximum ability and scrape the cylinder walls firmly.  You may find that after doing this regularly, your oil consumption will decrease.

<{POST_SNAPBACK}>

I will try that. I am going to call the dealership and have them check everything out as well.

Do you know if I can expect a courtesy car while my car is in the shop since its a CPO?

[calh4289]

so... does anyone have any ideas about this??? Is this normal?

3. When I start the car for the first time of the day i generally have to let the car warm up before I take off. Otherwise the car wants to die when I give it gas (almost like it is flooded).

[umn]

...

1. I recently got my oil changed. The following day a friend said that I was blowing black smoke out of my exhaust when I shifted gears. I have never seen this problem in the past and I am assuming that it was just because the oil was topped off.

...

3. When I start the car for the first time of the day i generally have to let the car warm up before I take off. Otherwise the car wants to die when I give it gas (almost like it is flooded).

...

Hi,

this would be consistent with a defective oil separator and can seriously damage your engine. Known problem with the older models. I'd have it checked out by a garage ASAP and certainly would not redline it.

I don't want to cry wolf, but it's certainly a possibility.

Cheers,

Uwe

Edited June 1, 2005 by umn

[Scouser]

...

1. I recently got my oil changed. The following day a friend said that I was blowing black smoke out of my exhaust when I shifted gears. I have never seen this problem in the past and I am assuming that it was just because the oil was topped off.

...

3. When I start the car for the first time of the day i generally have to let the car warm up before I take off. Otherwise the car wants to die when I give it gas (almost like it is flooded).

...

Hi,

this would be consistent with a defective oil separator and can seriously damage your engine. Known problem with the older models. I'd have it checked out by a garage ASAP and certainly would not redline it.

I don't want to cry wolf, but it's certainly a possibility.

Cheers,

Uwe

<{POST_SNAPBACK}>

My car and another friends 996 both had the oil separator switch replaced last week due to a frightening noise at start up that sounded like a bag of nails in the engine. All is OK now. But my car never needs to be topped up despite all its RMS trouble. In fact I just did 2800 plus miles to Spain and back and it was driven hard and it didn;t use a drop of oil.