View Full Version : Blowing oil smoke out

10-01-2007, 04:51 PM
Ok guys, I may have been taken, but here goes. I now have blue smoke coming outof the exhaust when I idle after driving the thing. My oil levels were low and I had to put more in. I should have done a compression test on all cylenders when I bought it. I think My rings are going or are gone. I still have power but I am losing the oil. can anyone give any insight to this and wht it typically cost to have them replaced if I need it.

10-01-2007, 05:11 PM
Ok, sorry to step on my sweet hubby's toes; but I don't think there is "blue smoke".

There is smoke on start up, to me more white/grey than "blue"..eheh...and not real thick...actually rather thin.

On idle no smoke; only on acceleration and smells. I thought the smell could be coming from the fact he has no cat...but he was low on oil (not registering on dip stick) the other day so we need to find where it is going.

Any assistance would be helpful....THANKS GUYS! :)


10-01-2007, 05:22 PM
Well if the valve seals are bad then oil could be leaking past them and giving you the smoke. I wouldn't judge the oil level by the dipstick, they tend to be off a little. What I would do is drain the whole thing and fill it up with the proper amount specified in the manual and then mark the dipstick where it is at. Mine is aftermarket and reads on the low side but I know I have all 6 quarts in. Hope this helps, Chris

10-01-2007, 05:34 PM
I am going to get the oil changed tomorrow; as hubby has no time (work/school). I thought we had it done but he said he didn't...oh well.

The oil light had come on and when he checked the levels it wasn't registering on dipstick. ;)

He is worried about the 'oil' smell; I claim it is more of a 'gasoline' smell. Not sure I will ever win that argument....teehee...not that I need too. It really smells as though it is running 'fuel rich'. You smell as though you have just pumped gas if you stand behind the car as it is revved.

Just trying to see if there could be other issues instead of him automatically going to "engine" issues. I have to say it wasn't smoking a week ago when we first purchased it; so not sure what has changed between now and then to cause this issue.

Thanks again

10-01-2007, 06:01 PM
If the car has synthetic oil in it, then the "fuel smell" you described is probably the synthetic oil burning. Burning synthetic smells different than conventional; I found that out the hard way ealier this year when I put a hole in a piston, lol.

Change the oil and verify you have the right amount in it. On the 99/01 engines with stock oil pans, I run 6.5 quarts at least (I prefer more). Ford says 6, but that is too low in my opinion and from everything I have seen. The DOHC engines hold a lot of oil up in the heads.

You need to get it over to a shop that can determine the cause of the burning oil.

10-02-2007, 08:11 AM
Just thought I would chime in on this one. If you plan on marking the dip stick where the oil line should be, best to start it up first to circuilate the oil and fill up the oil filter first and let it sit for a few hours before marking the dip stick.

Sources for oil passing into combustion chamber:

Worn valve guides
Worn rings and or scratches on cylinder wall. This would also cause fuel to get in the oil as well as lack of power. Would also increase crankcase pressure considerably. This could be a result of too rich a fuel mixture which leads to premature engine wear.

PVC system is also a culprit for oil consumtion. PVC valve and breather line will pass oil into the intake. Inspect throttle body and intake tract for traces of oil.

Sometimes the blueish smoke could be a result of rich mixture when letting go of the throttle after a WOT run.

Things to look for: Instpect the spark plugs. This would indicate what the engine is doing. If burning oil the plugs would be black and probably gummed up. If the white smoke at start up is a concern and if you have a head gasket leak the plugs would probably look super clean or rusty. Light grey, tan is normal.

I had a 2001 Cobra that would use about a quart of oil in a short time. The cause was the lack of baffles in the valve cover for starters. Most of the oil consumption was throught the PVC system. I tried using breathers on the valve covers and eliminated the PVC system but that resulted in oil every where in the engine bay so I put the PVC system back in place and used an air compressor air/oil separator on the PVC line. That help a great deal but did not resolve the issue. Needless to say I sold the car shortly after installing the air/oil separator due to the hard to refuse deal I got on the 04 cobra.

Hopefully you do not have a severe issue with the car. :thumbsup:

10-02-2007, 08:16 AM
If it turns out to be the rings, that would be the time to upgrade since it would require an overhaul anyway. Cylinders would have to be honed, and rings sized to fit. If you still have the hyperetic pistons, change them out with forged and replace the connecting rods at the same time with forged as well. IT may be possible to resleeve the block but probably expensive.

If it is just the valve guides, I believe the heads need to come off so the cost would be close to a grand anyway (mostly labor). I could be wrong on that since it is just a guess.

10-02-2007, 08:20 AM
Almost forgot this one...... One main source of oil loss could be the rear seal. If the flywheel has been replaced recently chances are the rear seal was neglected or replaced and got nicked. If the leak is just enought to drip out the vent in the bell housing it could be hitting the exhaust. Oil on the ground may be a good indication or a wet bell housing and oil saturated transmission would be a giveaway for a leaking rear seal.

10-02-2007, 02:55 PM
We know for sure there is no oil 'leak'. When the car was up on the lift for the rear end work it was very clean. And same goes for the top side of the engine...no oil anywhere.

Now, the smoke issue. Hubby got it confirmed from another friend who does have 'blue smoke' and of course he agreed w/me....our 96 cobra isn't producing blue smoke. It is (white/greyish) because of the straight piping/no cat same for the reason why we smell some gas. Because it doesn't do it unless you get on the accelerator hard.

I did have the oil changed today and the air filter; they also had to replace the drain plug as it was stripped...interesting.

I will be getting the transmission fluid done and it was recommended we get the pcv changed, fuel filter and .... something cleaned...can't for the life of me remember now. It is on the receipt....grrr...it had something to do w/the fact the air filter was black and sooty.

So that is where we are right now. Now, we need lowering springs/shocks/struts....any recommendations?


10-02-2007, 03:24 PM
I would recommend Eibach springs to lower the cobra. :thumbsup:

10-03-2007, 12:50 PM
Glad you got the smoke issue figured out. I would recommend H&R springs. Not that Eibach's are bad, but I've had both and enjoyed the H&R's more. They felt more responsive, better handling, and better ride quality I thought on a performance stand point. They didn't feel like they let the car roll as much as the Eibach's. I just felt that the H&R's out performed the Eibach's.

Just MHO.