PDA

View Full Version : smokin


AHHHSUM
09-15-2004, 12:57 PM
Hi folks I have a 0/3 cobra vert, the car smokes on start up only, very noticable and embarassing the dealer tells me this is normal(in writing) performance is great but i would like to know if anyone else had or has this same problem any help would be greatly appreciated Thanks, Doug

Big T
09-15-2004, 03:29 PM
Mine did this for a month or two when I first got it. Wen't away the more I drove it. I was told it was normal.

Skill
09-15-2004, 05:40 PM
Never, not even a puff..................Skill

AHHHSUM
05-13-2005, 10:36 AM
is it possible that my 0/3 vert could be suckin a little oil through the pcv valve and is there a filter that can be installed to reduce this problem of smokin on start ups any info would be of a great help ..........Thanks .......Doug

SVTcobra04
05-18-2005, 01:29 AM
i sometimes notice a puff of smoke right after a wash it.only if i start it up after thought.

ausie
05-18-2005, 07:48 AM
ahhhsum, yes there are filters you gan buy just to reduce or eliminate oil passing through the PCV line. It is common to find oil in the intak plenum under the supercharger which is found when people replace the eaton with other more effeicient blowers. There is a cheap method by using an air/oil separator that is used with air compressors that removes the crankcase oil out of the air lines. I think it is made by Cambel Haussman or something like that. Take a look at the STEEDA website they have the exact same thing that you can find at wal-mart or lowes/home depot or even sears hardware. There are other sources for different types such as Greedy
http://www.morepowerracing.com/prodtype.asp?PT_ID=2000&strPageHistory=cat

as well as the one from accurate machine works which looks like a better designed part.
http://www.accmachtech.com/pcvcatchcans.htm

I had the air/oil separator from lowes. It worked okay, but since I started using the Lucas oil "pure synthetic" stabilizer the filter did not trap any more oil. I decided to remove it.

When adding an oil separator, you are also adding potitnail vacuum leaks to the PCV system which may hinder performance to some degree. Since most of the filters trap oil after the PCV (which acts as a check valve in case of back fire) they have to be cleaned evey so often. IT would be great to have a filter before the PCV so that the excess oil will return to the valve cover.

As for the smoke, keep in mind that our cars have an iron block and forged aluminum pistons. When the motor is cool, the pistons will reduce in size. At start up, let the motor warm up before driving. This will allow for the pistons to expand within the cylinder walls. When the piston expands it will also close up the gap on the rings as well and reduce any oil passing by the rings. A 10 minute warm up when cold should reduce oil consumption as well as reduce the amount of wear casued by piston slap when the motor is under load (driving). Piston slap is caused by the cold pistons wobbling in the cylinders and is a common issue with forged pistons and iron blocks. That even exists with aluminum blocks as well but the metals expand at the same rate, however the iron sleeves in the aluminum blocks will also provide a different thermal expansion issue. Aluminum expands at a faster rate than does steel or iron and it cools down much faster too. Where as iron/steel has a slow expansion rate and will hold heat much longer it will take a while before it returns to the nominal size. It is just a matter of the physics of the materials invlolved.

Hope any of this helps. To some degree, it is normal , but in excess it is not. Some smoke may be a result of a rich air/fuel mix at start up while the emissions system is running in open loop (no EGR feedback). The rich mix is controlled by the ECU to act like a choke. Also don't rule out the amount of moisture in the air which will condensate withing the pistons, exhaust pipes, etc after the motor has been sut down. Most of which is usually trapped in the exhaust (there is a reason why there are small holes on the bottom of the stock mufflers is to allow condensate a place to drip out).

blk04cobra1
05-18-2005, 09:49 AM
no smoke here...but i was also told the noisy tranny was normal too...i would trust the opinions of the board and give it a few hundred more miles before buying something you may not need :thumbsup:

dewone
05-18-2005, 10:12 AM
As stated before oil or condensation puff out at start up. My 97 also has this trait, as well as my 85 Z28 which has done this since I bought it at 20,000 miles it now has 170,000 I don't think you need to worry.

ausie
05-19-2005, 08:11 AM
It all depends on the color of the smoke. If it is blueish to black, it is probably due to the rich AF mixture which is okay if not too excessive. Oil burning will also give off a thick blueish white smoke. You could always start it up and then stand behind it while it warms up. The odor of the smoke should give it away. If it is burning rich you will smell fuel. If it is burning oil, there should be no mistake what that smells like. However if it has a sick sweet smell sort of like rotting a rotting bee hive or sour honey then it may be some coolant in the combustion chamber indicating a weak head gasket. More than likely it is condensation and or a rich AF mixture at start up which I think is normal. IF you think there is excessive oil passing the PCV valve, you can allways monitor the oil level on the dip stick. If you drop a quart within a thousand miles of driving then either you are consuming oil from the rings or the PCV line. I did run a filter for a short time. It did fill up with oil from time to time, that is until I added a small amount of oil additive to the oil (Lucas "Pure synthetic"). I am not trying to plug the product but I did notice a lack of oil in the filter after using it. It may or may not reduce the oil passing throught the PCV line but after 3000 miles and no large amount of oil in the filter I was convinced that the filter was not necessary. There is a down side to this story, since the lucas additive coagulates the oil to some degree it may effect the oil spray on the piston skirt which would not be a good thing. Perhaps coagulation is not the correct term. Maybe cohesion is the proper term.