oil blow by?

88_GT_5_oh · Apr 26, 2006

trying to figure out whats going on with my car, when i go WOT in 2nd a puff of smoke eventually will puff out the back of my car, and then i can kinda smell oil a little bit. now i pulled all the plugs and took a look after some hard wot pulls and they seem perfectly fine, no oil at all and are a nice brownish color. the bottom end has only 5000 km's on it (3500ish miles) so i don't think its the rings. i took off the line that goes from the TB to the oil fill cap and it was soaked in oil on the inside. i replaced the cap with a breather. its a little better but there is still a little bit of smoke when i go wot. i want to get this sorted out before i put my turbo on. basic setup is 306/TW heads/street heat intake/trickflow cam

any ideas? i can get a compression checker but i want to explore my other options but i don't think that is what it is cause the power is definetly all there and will roast the tires from a 40 km/h roll in second

SEE POST #9

vristang · Apr 26, 2006

This seems pretty common with modified 5.0s

Take a look down the oil fill neck, if you can see the rocker arms then you will want to install an oil baffle on the inside of the valve cover.

Putting a breather on the valve cover of a pcv equipped car is a no-no. This will effectively create a vac leak via the pcv. Atleast with the VC/TB hose the air entering the intake via the pcv is metered by the MAF.

It is likely that you will need to make some revisions to the pcv system when you add boost. Many people have had issues with keeping boost pressure from entering the crankcase through the pcv.
You are still right to want to sort out the current problem though. In my opinion.

jason

Some more reading on the topic...

From the FAQ page on my site http://www.freewebs.com/vristang/faqs.htm

The pcv is an emissions device that allows the pressure and corrosive gasses in the crankcase to vent, without venting these harmful gasses to the environment. The directional valve is in place to prevent a backfire from spreading to the crankcase. In the event of a backfire into the intake manifold, the pcv is supposed to seal shut, preventing the flame front from travelling into the crankcase. Without the directional valve in place and fully functional, a backfire would also cause a crankcase explosion.
All motors will experience some degree of blowby. Even a freshly rebuilt motor can experience between 5-10% of blowby, as checked with a Leakdown test. Blowby of combustion gasses introduces fuel and other combustion by products into the crankcase. Raw fuel, moisture, and various acidic materials will all contaminate the engine oil. Moisture can also enter the crankcase due to condensation overnight. The good news is that most of these contaminants are highly volatile, meaning they will vaporize at realatively low temps; around 200F. Once these contaminants and moisture have volatized though they must be purged from the crankcase. This is where a crankcase ventilation system comes in.
In the old days the crankcase was vented to the atmosphere via a hose that ran under the car or into the exhaust. The downside to this is that these volatile materials were being introduced to the atmosphere, increasing environmental damage. Now a Positive Crankcase Ventilation system is in use. In a positive venting system the crankcase contaminants are purged into the intake manifold so that they can be burned in the normal combustion process. This is very effective at reducing the amount of unburned HCs that are released to the atmosphere.
The downside is that when performance modifications are made to the motor, the stock pcv system can have trouble flowing the right amount of air from the crankcase. Excesive volumes of contaminated air flowing out of the crankcase, can pull excessive amounts of oil into the intake manifold.
Troubleshooting Your Oil Control Issues.[/LEFT]
The first step is to find out where the oil is coming from.
Pull the Throttle Body/Valve Cover hose from the TB. If it is wet with oil then this is an entry point. The normal causes of this are excess blowby (which needs to be ruled out with a compression test), or the VC baffle has been removed for rocker clearance. Just looking down the oil filler neck should reveal if the baffle is in place. If you see rockers, then it is time to get creative and fab a baffle. If there is no baffle but the TB/VC hose is bone dry then you may be able to get away without using a baffle.

Next pull the pcv hose. Again if it is wet with oil, this is an entry route. The best solution I have seen for this is a separator from Steeda, Home Depot, or Lowes. For about $25 (The Steeda unit will be more expensive) for the separator and fittings you will be able to remove most of the oil before it gets to the intake.
Also, you need to verify that the pcv screen is in place. This often forgotten part is located underneath the pcv in the back of the intake, and helps remove oil mist from the crankcase gasses.

From what I have seen, the oil accumulation in the intake will be greatest when the car is left to idle for some time (stuck in traffic or idling in the driveway), then with some rpm the oil is picked up and thrown into the combustion chamber. If you live in a humid part of the country, or see a fair amount of condensation on the ground in the morning, then you will most likely notice some moisture in the separator. This is fairly normal, as overnight condensation will form on the inside of the engine block. Once the oil gets up to temperature, this moisture boils off, and collects in the separator.

This is a pic I took of my engine at its worst. The car had been at idle for several minutes before I shut it off.
http://forums.stangnet.com/attachmen...8&d=1123979745

Hope this helps some,

Reference:
http://www.steeda.ca/catalogue_product_type_918.asp
Home Depot
This is the Fram pcv screen pn #BA8113
This is the NAPA pcv screen pn #6978

88_GT_5_oh · Apr 27, 2006

so the breather in the oil filler neck is bad? i see tons of cars with it removed. i don't have a baffle cause i took it out so i could clear my rockers, i guess i could figure a way to rig up a baffle or buy some new valve covers but i don't understand why its a bad idea to have the breather there instead. i am gonna try the oil separator though, cuase that hose is soaked too. just to clearify the hose you put the seperarator on is the one going from the back of the lower intake to the upper intake, about 1/2' thick hose?

you got any tips to help me be prepared for the boost with the pcv system?

89Notch · Apr 27, 2006

I just bought that same steeda oil remover, I haven't installed it yet though I want to see how much oil mine is blowing by as well

88_GT_5_oh · Apr 27, 2006

i just went to home depot and canadian tire (local auto store) and all the inline air tool filters are too much (like 45+) but i know of this other place in town that sells this kinda of stuff for alot cheaper

here is what i think i am gonna do
don't know how i am gonna put baffles in the vlave cover sooooo i am gonna use this its only $12 so i may as well give it a shot i will try this one inbetween the valve cover and TB on that line, the demensions are preety small so i can kinda hide it too (item I or J i'm gonna look at them tommorow and decide)

and this is the one i am gonna get for the larger line at the firewall

looks ok? obviously gonna paint it black

KENS89LX · Apr 29, 2006

another thing you should check is the pvc is good and there is also a screen in the hole where the pvc goes if you never have cleaned it that is a good chance that is your problem.

timewarped1972 · Apr 29, 2006

this is a knock off of a more expensive one, but looks like it might work well in these situations and isn't too pricey. theres others things listed under "oil catch can"

http://cgi.ebay.com/ebaymotors/GRED...ewItemQQcategoryZ33556QQitemZ8060445021QQrdZ1

Bad92GT · Apr 29, 2006

i have the same problem.. mine comes through the PCV valve when i get on it.. (typhoon intake doesnt have a screen)... just do a oil seperator

88_GT_5_oh · May 1, 2006

so where are you guys putting these filters, i am gonan do it after work tommorow

it goes on the line that goes from the pvc at the BACK of the lower intake to the upper intake? and where exactly are you mounting these things? i tried pictureing it but i can't see where to put it. pics would help

emagdnim · May 1, 2006

88_GT_5_oh this is a common problem with new engines if the rings dont seat perfectly right away causing blowbye. Give it another 5000 miles and the problem should go away on its own I had the exact same problem. People will argue and say if rings dont seat fast things just get worse but ive seen in several intenses personally where things wear in over a couple more thousand miles and cause a better seal.

dragnazz5.0 · May 1, 2006

ive got a separator on my car and never had to empty it until i figured out i had a bad injector. well the motor has about 15k miles on it and never had a problem until now. i burn oil and get lots of blowby because those rings got washed out. oh well, not trying to steal the thread. just get an oil separator, im trying to figure out what to do about the filler neck also.

88_GT_5_oh · May 1, 2006

it was fine for a couple thousand kms. it jsut kinda strted happening, which is kinda weird

oil blow by?

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