96 GT burning oil?

[patrickg302]

I've got a 96 GT 5-Speed with about 140,000 miles. I've been noticing that about 2000 miles in to my oil changes the engine burns off about about quart of oil, and from time to time i'll see a small amount of smoke from the exhaust if i stand behind it. I'll add about a quart in until my next oil change and usually all is well. I change the oil every 3000 miles with 6 quarts of Motorcraft synthetic blend 5w30, and I use the appropriate Motorcraft oil filter. My modifications are PI manifold, K&N intake, BBK offroad H, flowmaster 44's, and SCT xCal3 tuner. The smoke is what worries me a bit, i've checked the coolant and the oil, both always look clean and never milky, and i've pulled the plugs, none off them have any oil saturation.

Any thoughts on what could be going on? Could the lack of cats cause the small amount smoke? Its not drastic by anymeans, but still makes me wonder.

 

[Lugnuts]

If you are not leaking it, you are burning it. If you are burning oil some smoke is to be expected. Does it typically puff smoke at startup after sitting a little while?

 

[N8Dogg98]

It's not at all uncommon for the mod motors to burn 1 quart every 1000-2000 miles. If you see some blue smoke under hard accelleration, it's probably worn piston rings. If the car idles for a while and smokes when it's revved or smokes during decelleration, then it's most likely valve seals.

 

[Maxium]

Here's a different spin on it. What does your coolant color look like? Does it look like you have oil in it but no coolant in your oil? It did for me, and I found that the gasket between the block and oil filter was no good. When the gasket goes bad, the oil can escape into the coolant passages. Needless to say, after replacing it (which was easy), it obviously used a lot less oil.

 

[patrickg302]

Coolant is nice and green, and no blue smoke, just your typical gray smoke. It doesn't smoke on deceleration, just if it's sitting there for a second then i give it gas i'll see some for a second then it goes away. Is this something i should be worried about like seals or rings blowing out? Or is it just something these motors do when they get up there in the miles.

 

[bhuff30]

Sounds like it could be the valve seals. My 97 GT does the same thing and uses a quart every 2-3k miles. I sometimes see a puff after taking off from a prolonged idle, or even more rarely on a cold start. The engine has used about the same amount since we got the car with 45k miles. It has 192k miles now, so obviously it doesn't cause any problems. Just keep it topped off.

Ford doesn't consider oil use to be a service issue until the engine uses a quart every 500 miles or so. It'll be fine.

Or... you could use it as an excuse to build up some PI heads to swap in.

 

[Lugnuts]

Sounds like valve seals to me. What mods do you have? While burning some oil is not going to mechanically kill you, you may have O2 issues down the road and I would not say that performance is optimum. New seals are not that expensive but you can time it to be done with other mods if you wish - meaning that this is not an emergency.

 

[patrickg302]

Well i check it every week and keep it topped off if it gets low, and i don't have cats or rear 02's so 02 issues i'm not worried about, so i guess i can put off valve seals for a little while if that wont harm it? The only other things i plan on doing with this car is a nice clutch, 3.73's, and maybe some mildly upgraded cams, so i guess i'll get the valve seals done when or if i decide to do cams.

Are there any oil additives out there that anyone would suggest to help with the smoke?

 

[Lugnuts]

High mileage oils have conditioners in them that will help a little. These additives cause the seals to swell slightly which aids in sealing but difference is negligible in my experience. Only sure way to fix it is to fix it but if you are planning cams, then you would be wise to tackle both cams and seals at the same time (and consider replacing tired valve springs with those that offer the correct seat pressures for the cams).
Just my 2 cents..

 

[1987stangman]

I have responded to a few post like this in the past. My 96' GT was doing the same thing. For me I could pull the plugs and the #8 cyl would have oil on it and it would consume a qrt. of oil over 1500k to 2000k miles so I always had to keep an eye on it and the engine ran pretty good even with over 150k on it. I did not address the issue until I did the engine swap and sold it to a friend of my sons that needed it. I went ahead and installed all new seals and his friend has not had any oil consumption or smoke issues since he installed it.

If you do a Google search on this you will find that earlier 4.6L NPI motors have issues with these seals. I have noticed that PI motors are not as bad.

Installing new seals is not hard, but I would not want to do it with the engine in the car. More than enough folks have done it though!

 

[patrickg302]

well seals it is, i will be getting that done. thanks for the help everyone