[Ryan Paymaster]

I've posted this before and looked all around the internet for about a year now and still haven't found anything.

What I'm looking at is my 1996 Cobra with full bolt-ons including: K&N FIPK II, O/R H-Pipe, SpinTech Exhaust, Long Tube Headers, SCT Tune w/ Rear O2 turned off. I really can't think of anything else that is engine related - aluminum driveshaft and gears / suspension won't make a difference obviously.

The car was bought with 55,000 miles on it, I'm around 63,000 now. The only previous mods were the exhaust and headers. My problem here is this: The car runs great and has plenty of power. It does consume oil, maybe upwards of a quart tops every 3,000 miles or so. When I give it gas past 6,000 RPM or so and stay on it she smokes pretty well. I've given the car a full 'tune-up' and have done everything that is obvious such as filters and such.

Here are some info that I'll list just to throw them out here:

Basic Information
I do have LT headers and no cats - I don't think this should affect it.

~6,000RPM > it smokes, it's sometimes a bit dark, white, maybe a tiny tint of blue. If I rev it up at idle it will shoot white for a second and then calm down to just slight puffs for a bit. Seems to happen at WOT but I'd say it's generally the extremely high RPM range. It just lays a pile of smoke down and it's very visible from my side view mirrors.

I have had oil on the spark plug threads but last year when replacing the spark plugs the tips actually looked 'right' as they should.

Consumes oil, but never smokes during normal driving or on start-up/idle.

The previous owner(s) never changed the coolant. My coolant doesn't seem to be going anywhere. Ford had to flush it out twice to get it clean. It's now about 6 months and I haven't had to add anything and it's still green as ever - it used to be filthy brown.



I'm going to give myself a crash cource in compression / leak-down tests. I don't want to spend the money paying someone to do something I could learn. I really just want to find some ideas on what is behind this. The car is in surprisingly amazing shape for it's age and relatively low milage for a 1996. Runs strong as it ever has too.

What could this be? I would almost say it was valve seals if it smoked on start up. This smoke seems to be only when I'm really on it. I'm really doubting it is a piston ring issue only because I don't want it to be that. Maybe I'm missing something simple like replacing an intake gasket that may be wrecked or something similar. I've tried a few oil additives short of "No Smoke" and the like. I don't want to pour honey in the motor - I am trying Lucas Oil Stabilizer now but it's no miracle, it's done nothing just like every other additive I've ever tried (short of Seafoam, I believe in that stuff.)

Worse comes to worse and it's valve seals I'll be learning those this winter. Piston rings - I'll be learning how to rebuild a 4v.

Thanks guys, sorry for posting this but it's been a year and the 4v forum may know a little more about this than I.

[Doc8224]

First let me start by saying you are not alone with this problem. Alot of mid to late 90's cobras suffer the same high rpm smoke, some worse than yours, some not so bad. It could be any of the things you listed and until you start making your way down the troubleshooting list it will be hard to pin point just one cause. As for the oil on the treads of the spark plugs, a thing often overlooked is the valve cover gasket. The seal around the spark plug opening in the valve cover can start to leak anb give you oil on the upper side of the plug. Valve seals are certainly capable of causing your problem. You have the right idea though, do the leak down and compression checks and see if thats your problem. But you can have good compression on the test and still get blow by at high rpm's. What weight oil do you use? Have tried going thicker and see if that helps any at all? That could answer some questions for you as well. Don't mess with the additives, just try a heavier weight for 1 oil change cycle and see. Then I would pop off the valve covers and inspect and replace the valve cover gaskets if neede. These are a couple of cheap easy trouble shooting things to try, that will eliminate some of the easy things it could be.

[Ryan Paymaster]

5W30, sometimes 10W30, but the first weight means very little for this issue.

I'm going to give the valve cover gaskets and O-Rings on the spark plugs a try. I might do the intake gaskets too.

I guess I'll run a leak down first - that should give me a good idea. I know quite a few late 90's Cobras have this issue, I'm hoping someone out there had a similar problem.

Thanks for the help again Doc, it's useful. Going to go ahead and try valve cover gaskets and the "easy cheap" stuff.

[BizCutt]

Its a pretty common issue....had the same deal...heres what i did... had to remove upper intake to clean oil from intake...what happens is the vaccum actually sucks oil from the valve cover vented into the intake....if you really want them vented into the intake i put a filter, such as one that is found on an air compressor, bought one from sears for like 30bucks...then you have to run the pcv line to the filter and than back to the intake....you have to drain that filter quite frequently though...or you can just buy some heater hose and run the hose from each valve cover vent and dump it into the front wheel wells...just make sure you run it a little higher than the intake height to help avoid to oil flow leakage... and just plug the ends on the intake where they were connected...

[Ryan Paymaster]

I installed dual oil catch cans on each side and the driver's side actually collects a good amount of oil.

I don't drive the car a whole lot, it is a daily driver. I don't really get to floor it that often.

So I have my filters on but the key here might be taking the upper intake off and cleaning everything out inside of there?

Thanks so much for the reply - exactly the information I was looking for. I could never find anyone with the same issue.

[BizCutt]

The catch cans I had filled up real fast...I was told I could put a baffle in the valve cover to keep the oil from being pulled out but I just ran heater hose to the wheel wells and called it a day...worked great..defly take the upper intake off to clean any oil that has built up in there for sure....let us know what fixed it

[Ryan Paymaster]

I completely cleaned out the upper intake and thoroughly cleaned the lower intake as well. (Oil was sitting down in the bottom of the lower intake - I've cleaned everything up.)

This is what it looked like before I cleaned it even further , it's now pretty spotless in there.




The problem is still there, maybe a little lighter. I know my driver's side catch can collects oil like mad at high RPM.

When I floor the car I get a massive Ford PowerStroke black cloud of exhaust - obviously I'm running rich, cats or not cats, this is rich.

The white smoke shows up above 6,000RPM. When driving it it shows and then here is what is odd:

If I sit in my garage and I give it a fast rev to 6,700 it shoots the white smoke (pure white, I don't see blue in it) and then it comes back down to idle it still puffs white smoke for at least half a minute. I put my head over it and then even smelled it indirectly and it doesn't smell like oil. From what I know and understand oil is a pretty nasty smell when it's burning.

What's stumping me here is it more or less smells like not a whole lot but exhaust and it blows it at the real high RPM and then it puffs it out for a bit afterwards.

I know to correct the cloud of black that'll take a tune. Maybe it's possible I need a tune all around? Who knows.

[BizCutt]

Dat was oily for sure...She prolly pulls better up top now too...The driver side is worse than the passenger..There is no baffle in the valve cover to delflect the oil..it just gets sucked right out at higher rpm...its possible that all the oil that was in the intake also passed throught the entire engine, heads, exhaust,etc...not sure what kind of exhaust you have...is it catted or not??? white puff puff could just be condisensation...try to run the lines into the wheel wells and just eliminate the catch cans all together...

[htaak]

valve stem seals

[Ryan Paymaster]

The car has SpinTech exhaust with an O/R H-Pipe, no cats. I also have long tube headers.

As long as it's not piston rings I'm satisfied, I think I can tackle valves this winter.

Maybe with the intake cleaned up I just need to give it some time to maybe burn anything left off. There was definitely a ton in that intake, nearly a pool in the bottom.

[Doc8224]

Are you still running the hose from the valve cover or do you have a filter on it? I would do the filter if you haven't already.

[Ryan Paymaster]

Originally Posted by Doc8224 Are you still running the hose from the valve cover or do you have a filter on it? I would do the filter if you haven't already.

I've got a filter on each side. The smoke seems to be far less intense. I have been running filters for about 5 months now.

Today I didn't see any smoke, but I didn't try for it either.

If it was oil doesn't oil burning smell rancid? The smoke that comes out smells almost odorless or just flat out like carbon/exhaust.

[Doc8224]

Originally Posted by Ryan Paymaster I've got a filter on each side. The smoke seems to be far less intense. I have been running filters for about 5 months now. Today I didn't see any smoke, but I didn't try for it either. If it was oil doesn't oil burning smell rancid? The smoke that comes out smells almost odorless or just flat out like carbon/exhaust.

Depends on the amount of oil being burned. You have no cats so you have the little oil that is burning mixed with hydrocarbons and carbon monoxide so it will be faint unless there is a substantial amount.