Twisted

Just wondering if anyone can help me to interpret the following information:

As some know, my car uses 1 quart per 1k miles. It runs stronger than average, and all spark plugs look perfect. There are no leaks. Anyway, I had my wife help me to perform a smoke test. I drove her car, and she drove the GT. I drove so that I was directly adjacent to the GT's tailpipes--where I could see really well. My instructions to her were to accelerate hard in second gear, take the rpms to 5k, and then to take her foot off of the gas, let it wind down, and repeat the sequence. Well, she did exactly what I asked, and there was not a trace of smoke either on accel or decel.

Then, I went home, decelerating down a short hill to my apartment. I parked the car, opened the door, and peered around to the back of the car while still in my seat. I revved the engine hard, and saw a small plume of oil smoke (blue/white) exit the tailpipes. Then I kept revving the car hard, but did not continue to see smoke like I did initially.

Also, last week, I took a video of me burning up a desolate highway. The camera was positioned outside of the car. I saw no smoke on accel or decel, but did see a small puff of black smoke when I shifted from first to second gear at astronomic RPMS. I have been trained to think black smoke=rich A/F mixture; however my plugs are a uniform shade of grey.

My questions are:

1. What does all of this mean?
2. Is it possible that the blue/white smoke that I saw is oil burning that has been pulled into the intake through the PVC system?

Steakburger

I seriously doubt your pushin' 1qt of oil per 1k mi through the PCV. Run a compression test. I had an '89 (see pic) that did the same thing, no trace of smoke but it ran like hell. I didn't do anything about it cause it was a high-milage (158k) daily driver, and it ran so good I just keep adding the oil. My wife was driving behind me one day and complained that my car smelled, which I attributed to be burning oil, even though you couldn't see it. Again, I never did anything about it cause it ran fine and I didn't do any racing w/it.

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[IMG]local://upfiles/45308/C1745899DACD4D1D82CCF83414D819C9.jpg[/IMG]

Twisted

Thanks for the reply, Steak. How long were you able to run it like that? Did the oil usage increase over time, or did it stay the same? I don't mind adding a quart every now and then, so long as the consumption stays the same.

Nice car, by the way.

93foxgt

You know, I'm down about the same amount of oil per 1k, maybe a tiny bit less (oil).

I've only got 84k miles too, and have no spots under the car, or smoke. What's weird for me is that the plugs for cylinders 4 and 8 both had a tiny bit of oil on the threads and some deposits on the tips of those two plugs only, but just like you guys, it runs like hell.

Twisted

Thanks for the reply, 93. It's a strange thing. I'd understand the consumption if I had some oily plugs or deposits on the tips, but my plugs look perfect. I wish I could contact some of the previous owners of the car, and ask how much oil the car was using when they had it. If it's been doing the same thing for 60k miles, then I won't even worry about it. I'm just worried that it's gonna snowball.

93foxgt

Yeah I hear ya man.

By the way, what does my problem sound like to you?

I had a chip installed by the previous owner that bumped the timing so that it detonated around 5k when I put my cobra intake on. I drove it like that (not bringing it over 5k causing detonation more than 5 times in total). I didn't know that was the infamous "pinging" as it sounds more like a loose set of hubcaps bouncing around.

What would you attribute the 2 oily plugs to? Sorry to hijack, Tom, but now you got me worried. It didn't look too serious when I checked it out, but now I'm getting worried. And how would I fix this problem, or would I need new heads?

Twisted

Well, if you're sure that the oil on the threads of the plugs came from inside the cylinders, rather than from an external leak, it would be either a problem with your piston rings or your valve seals. Did the deposits only appear after the predetonation occured? If your not sure, you could switch your plugs around (or get new ones) so that the plugs with no deposits on them are in the cylinders that put the deposits on the other two plugs...if that makes sense. Then run the car for a while, and check the plugs in those two suspect cylinders again. I've heard that pinging (predetonation) can leave aluminum deposits on spark plugs. The best way to check the condition of your cylinders is with a leakdown test, or at least a compression test. Of course I should take my own advice, as I haven't had the chance to do either on my car yet.

93foxgt

Alright, I just replaced all of the sparks when I did my headers and wires just for the hell of it. I'll probably check them in a few thousand miles.

First- what is a leakdown test?

Second- we need to talk more about our club

86 5.0L

well, not sure if this could be it but I have the same problems, and one day my dad said it was oil passing the valve guides or some **** like that(Dont remember correctly) and thats why the inside of my tailpipes were covered in black gunk

Twister

it is either valve seals or rings, try a heavier oil