Question about burning oil

[kenamond]

Just thought to ask this...

Ever since I first bought my car new back in '96 I noticed it would burn a bit of oil getting on it hard when it was not fully warmed up (I'd see a bit of smoke when I'd accelerate).

At every oil change, I noticed I'd be about 1/2 to 3/4 low on oil (bottom notch on the dipstick or sometimes a bit lower).

It was this way from day 1 (well, I took it way easy for the first 1500 miles). Is this normal?

 

[mn95TSi]

well, you could be leaking oil from your valve stem seals...when the car sits for aperiod of time (you said the motor was cool), oil leaks down and accumulates, which is why you see smoke. the leak is small and slow, not enough to make smoke after driving for a while and what had accumulated had burned off.

an idea?

-alex

 

[kenamond]

Thanks. I was wondering about various things like that, but I wanted to know if this was normal. We're talking about a brand new car with 2k miles on it (back in 1996 after I finished a 1500 mile break-in). It did it then, and it did it for the next 9 years.

 

[NOFX0617]

I know my car burns oil constantly too, but i asked my friend who is one of the head mechanics at our Mitsubishi Dealership here and he drives a GVR-4 and his does the same thing. He said its because our engines run pretty hot especially when you get on it so I think it is just a normal thing for DSMs, but someone please correct me if im wrong.

 

[MrBoxx]

Everyone check your turbos for shaft play. It's easy to do and rules out that particularly vital part as far as leaking oil into the system goes. I know it's always the first thing I say when someone says their car is smoking, but after my T25 died on my and I had insane amounts of smoke exiting my tailpipe, then I saw the amount of shaft play that my turbo had (about an inch.... think about that for a minute) I realized it could have all been prevented by just checking the turbo every month or so. It takes all of five minutes and can prevent a whole host of future problems.

 

[kenamond]

NOFX0617: Thanks! That's what I was hoping, but I figured this is the place to ask.

MrBoxx: Thanks...but this was minor smoke during warmup under load throughout the life of my car (I ordered it in October, '96). I agree that you should check turbo play in an older car that develops a new smoking problem - so easy to do and so worth it when you notice play. I just wanted to know if this was normal for a new car or a car in good running condition.

 

[MrBoxx]

Ahh.. Now I see that "ever since I bought it new" part. My bad.

 

[Trucloner11]

How is shaft play created?

 

[MrBoxx]

There are a few causes, but I think one of the main ones would be a situation where a piece of debris damages either a compressor blade or a turbine blade and changes the balance of the turbo. If the shaft is unbalanced, the wheels will start trying to wiggle in oval orbits. Since the bearings and seals are circular and not oval, something has to give. In this case, the bearing and seal openings start to get oval shaped. This lets the wheels spin closer to the housings, which can damage the fins even more. The larger the openings in the bearings get, the more the shaft can spin out of play. Then it just kinda degrades from there. I'm sure there are other reasons why it can happen, though.

This is the end result:

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[kenamond]

And if you catch it before it damages the housings, you can rebuild the turbo and reuse the undamaged parts.