getting worried: burning oil? kinda long

[GT98]

My car is approaching 100k and I want to keep her running as long as possible. I've regularly changed the oil myself every 3,000 miles or so with synthetic, either 5W or 10W-30. About 5 months ago I had a shop change the oil for me. They used Pennzoil, regular oil. I checked everything afterwards to make sure they didn't screw me. Everything was fine and like usual there were no problems. About 2 months ago I changed my oil again, going back to synthetic 10W-30and just recently (within the past 2 weeks) my car seems to be spitting white smoke. Its more white then blue and it only happens if I kinda get on it from a stop or when I mash it on the highway. While cruising theres nothing. My roommate is telling me that you can't switch back to synthetic after using regular oil because the molecules or minerals are smaller in synthetic oil which will lead to some of the oil leaking through the seals. Oil pressure and water temp are reading normal and I just checked the oil and it's light brown, but its about halfway between the min and max on the dipstick. I put a little more oil in, like 1/6th of a court. It's only a little bit of smoke but I'm worried that this could be a bigger problem then I think. I plan on going changing the oil with regular oil from now on and using a heavier weight. I had a similar problem with my 96 monte carlo except it would smoke out the neighborhood whenever I turned it on, and it ended up being a blown head gasket. I just need some reassurance that some oil burning is normal for a car around 100k and won't cost me 2 months of fulltime work to fix it. How do I go about fixing this?

 

[5spd GT]

Some blow-by is natural after some miles. It wouldn't surprise me. Some have it and some don't. Depends on how it was driven and broken in, IMO.

That PI headswap will cause a bit more blow-by with the increased compression.

 

[GT98]

I've never taken it to the track and most of the miles are highway. I rarely drive it hard. I never did the headswap. The only real mod to the engine is the intake manifold. Unfortunately it's a stock replacement but it has the aluminum crossover.

 

[GT98]

bump

 

[BurningRubber]

I use some oil as well between changes. It was about halfway between full and add when I bought the car with almost 1k left to go before the oil change was due.

Im starting to get fed up with this thing... cars shouldnt use oil with lower mileage like quite a few people seem to be having trouble with.

 

[GT98]

I use some oil as well between changes. It was about halfway between full and add when I bought the car with almost 1k left to go before the oil change was due.

Im starting to get fed up with this thing... cars shouldnt use oil with lower mileage like quite a few people seem to be having trouble with.

Is your car shooting a little bluish white smoke too?

 

[BurningRubber]

Is your car shooting a little bluish white smoke too?

None at all... I have videos of me running it all out and nothing is coming from the pipes.

That is what totally baffles me. The PCV hoses arent oily like its getting blowbye, ive never seen it smoke on startup, under acceleration or anything.

Oil doesnt just dissapear.

http://videos.streetfire.net/search/mustang+vs+mustang/0/434A46ED-FF5C-47A7-B424-8C0EFDDD5190.htm

Im the white GT, nadda out of the pipes. Excuse the ghetto racing though, haha.

 

[DTNODYA]

I've never taken it to the track and most of the miles are highway. I rarely drive it hard. I never did the headswap. The only real mod to the engine is the intake manifold. Unfortunately it's a stock replacement but it has the aluminum crossover.

So it's a PI intake right???

 

[GT98]

So it's a PI intake right???

Whatever the stock manifold is. I bought a stock intake manifold with an aluminum crossover after the plastic crossover cracked.

 

[5spd GT]

Just because you aren't hard on it doesn't mean it wasn't beaten before with the previous or more owners.

 

[sjrtx]

So it's a PI intake right???

All the replacement non-PI intakes are updated with the aluminum crossover.

 

[DTNODYA]

All the replacement non-PI intakes are updated with the aluminum crossover.

But aren't they PI intakes with different gaskets for the NPI heads?

 

[kj99]

My 98 as 140k and it uses a little oil. About 1/2 quart every 2 - 3 weeks. But mine only blows out blue smoke if it is sitting at idle for more than 4 or 5 min. If i'm sitting at a drive thru and I rev it to move up to the window, it will put out a little bit of blue smoke.

Someone told me it's my valve seals are old and cracked. That's why I get the smoke after idleing.

 

[BurningRubber]

Someone told me it's my valve seals are old and cracked. That's why I get the smoke after idleing.

Thats usually about right. Worn piston rings will result in a more constant smoking, or a little bit under the throttle depending on how worn they are.

Valve seals usually belt some smoke after a long idle, or first crank and whatnot.

 

[the98stang]

My car is approaching 100k and I want to keep her running as long as possible. I've regularly changed the oil myself every 3,000 miles or so with synthetic, either 5W or 10W-30. About 5 months ago I had a shop change the oil for me. They used Pennzoil, regular oil. I checked everything afterwards to make sure they didn't screw me. Everything was fine and like usual there were no problems. About 2 months ago I changed my oil again, going back to synthetic 10W-30and just recently (within the past 2 weeks) my car seems to be spitting white smoke. Its more white then blue and it only happens if I kinda get on it from a stop or when I mash it on the highway. While cruising theres nothing. My roommate is telling me that you can't switch back to synthetic after using regular oil because the molecules or minerals are smaller in synthetic oil which will lead to some of the oil leaking through the seals. Oil pressure and water temp are reading normal and I just checked the oil and it's light brown, but its about halfway between the min and max on the dipstick. I put a little more oil in, like 1/6th of a court. It's only a little bit of smoke but I'm worried that this could be a bigger problem then I think. I plan on going changing the oil with regular oil from now on and using a heavier weight. I had a similar problem with my 96 monte carlo except it would smoke out the neighborhood whenever I turned it on, and it ended up being a blown head gasket. I just need some reassurance that some oil burning is normal for a car around 100k and won't cost me 2 months of fulltime work to fix it. How do I go about fixing this?

Well a 4.6 with 100k miles is going to burn a LITTLE bit of oil, so just keep an eye on it. As for the white smoke...sounds like a little bit of water is getting into the cylinders. You should do a leak down test to make sure it's not a blown head gasket. A compression test might be a good idea as well.

 

[BurningRubber]

Well a 4.6 with 100k miles is going to burn a LITTLE bit of oil

Why though? Thats pretty shi**y. I have one of the lowest tech pushrod engines made in America in my Jeep with almost 160k miles, 35k of which under my abusive right foot and it does not burn one single drop of oil between changes. AND its cleaner than the Mustangs oil when its time to change it.

Dont take that as a personal attack at all, lol.

All Im saying is that if every 4.6 is gonna start burning oil at 100k then thats a lack of quality right there for such a expensive, and modern engine. Mine also lets some oil disappear, and I dont see it leaving in the form of smoke, or leaking out... im at 94k btw.

 

[GT98]

Well a 4.6 with 100k miles is going to burn a LITTLE bit of oil, so just keep an eye on it. As for the white smoke...sounds like a little bit of water is getting into the cylinders. You should do a leak down test to make sure it's not a blown head gasket. A compression test might be a good idea as well.

If I've lost compression then I would be losing power too right? Because my car is still running like new, knock on wood. I didn't even know I was blowing smoke until my roommate saw a little shoot out when I gunned it on the highway and he was driving behind me. He said it was only for a second. Now I'm so paranoid that I look in my rearview mirror everytime I accelerate from a stop just to see if I see smoke. I've only noticed it once.

 

[GT98]

Oh one more thing, is it true that its bad to switch back to synthetic oil once regular oil is used?

 

[5spd GT]

Just because one does not notice any difference of oil level on the dip stick, does not mean it doesn't use any oil. I would guarantee you that Jeep (4.0L?) uses a bit of oil.

Rings will weaken and wear, oil will seap. Just the way it goes...

Also, unless you have track times to back up the "running like new"...it very well might not be. It is hard to tell small differences.

A high mileage engine has less friction and more bearing/ring tolerances because of the looseness it can get in higher mileage. Less friction equals more power. Now the "lost compression" can offset whatever minor gain you may receive. Catch 22.

 

[BurningRubber]

Yup, its a 4.0...

I know its not possible not to consume ANY oil at all, but what I meant was it doesnt burn oil to any noticable extent. The oil level doesnt move on the dip stick from the beginning to end of oil change, though it does quite a bit on the Mustang.

The oil consumption is neglegible on the Jeep, but I have to pay attention to it on the Mustang... if that makes better sense, haha.

Track times to prove it I dont have, but they would be a little offset by the larger tires and the dead weight from tools and other stuff its carrying. Its smoked plenty of ricers, few trucks, SUV's, and some 3.8 Mustangs.