where is my oil going

[swynx]

So i thought it was only the rear main on my sl2 saturn. drove to pullman on the down the grade i left it in 5th and barely hit the brakes at all. at the bottom of the hill after a stop light the car left a cloud of smoke. this is not the first time. and this is the only time it ever smokes. why does it due this? It has 218k on it.

 

[85_Ranger4x4]

why does it due this? It has 218k on it.

You answered your own question.

Is it a manual? I have heard of manual cars in general with some age sucking oil down past the seals/guides and burning it coming off of engine braking. I wouldn't think you would get much engine braking in 5th but that is somwhere to maybe start.

 

[swynx]

Haha yeah. i realized that after i posted. ive never heard of a car doing this before. and yes its a 5 speed manual. Anything i can do to fix it short term? I planned to do a conplete rebuild this summer. Before i left i filled it with oil when i got back it had sucked down about a quarter of a quart of oil.

 

[Captain Ledd]

2 possibilities:

I had a 88 Cavalier that burned (I shit you not) 2 quarts of oil per tank of gas. I let it go to half a tank, filled up, dumped a quart of oil in and kept driving. BUT, it NEVER smoked, not even a puff. I wasn't leaking it, the anti-freeze was fine, I had a number of very smart people racking their brains as to what the hell was going on.

Turns out, the PCV valve was missing an o-ring, and the intake was sucking up as much oil from the valve cover as it possibly could. Most of the smoke was taken care of by the catalytic converter (which after the fix was thoroughly clogged and left my brother stranded 2 years later).

After that, never lost a drop of oil. Go figure. Replacing the PCV valve should be a cheap fix in the $5 or less range. Make sure it seals tight.


The 2nd possibility is a Saturn specific one. On the 1.9L engines in particular, Saturn designed the pistons without oil return holes. Which more or less works ok, if you're a religious zealot about oil changes. But if you skimp on oil changes, and let even the slightest amount of sludge build up in the engine, BLAMO. You're oil control rings are plugged, and it will forever burn oil. The more sludge and plugged the rings, the more it burns.

This is why higher mileage Saturns "just burn oil". My 2001 SL has about 180,000 miles on it (5 speed stick), and still uses NO oil. BUT, we've owned it since new, it's never been past 5,000 miles for an oil change, usually 3,000-3,500 AND we've used engine flush on every oil change. And just for the haters out there, I use almost exclusively Fram filters on my vehicles.

Saturns are wonderful cars, I love mine.

 

[swynx]

Its been awhile since i did a complete tune up sounds like its about time

 

[RonD]

Its been awhile since i did a complete tune up sounds like its about time

yes, always a good idea

And yes, when you go down long grades with the car/truck in gear(manual trans) and throttle plate closed(foot off the gas) it creates a higher than normal vacuum in the intake, this creates more pressure on the valve guide seals which are 200k+ miles old, so you can end up sucking in more oil vapor via the valve guide seals than you would normally.
Piston Rings at 200k+ can also allow oil vapor in during the intake stroke when vacuum is high in the intake manifold.
High engine RPM and Closed throttle plate = high vacuum
This high vacuum is what acts as a brake when going downhill, on the intake stroke the cylinder can not pull in air fast enough with throttle plate closed so it slows piston and then crankshaft slightly, the higher the RPM, with throttle plate closed, the more the slowing effect and the higher the vacuum that can suck in the oil vapor.

Most manuals are fine for coasting in neutral, check on your model, I would try shifting to neutral and only using the engine as a brake(highest vacuum) once in a while on that hill, see if that lessen the blue smoke.
So if engine is idling most of the time going down the hill then vacuum is normal not high, so not sucking in as much oil vapor.

This same principle is why engines can blow blue smoke when you first take off from being stopped(idling) but not while driving, vacuum is highest at idle(throttle plate closed), so that's when the oil vapor is most likely to be sucked in, when you open the throttle plate to go the accumulated oil residue in the intake is pulled in and burned, blue smoke is the result.


Rubber seals like the valve guide seals can get harder over time, there are additives like Lucas Stop Leak that soften rubber seals to help them hold pressure better, might be worth a try.
Additives in most cases are a waste of money, so ........ up to you.

 

[Mark_88]

Haha yeah. i realized that after i posted. ive never heard of a car doing this before. and yes its a 5 speed manual. Anything i can do to fix it short term? I planned to do a conplete rebuild this summer. Before i left i filled it with oil when i got back it had sucked down about a quarter of a quart of oil.

A quarter of a quart?

Mine does that standing at the lights waiting for the waitress to bring another round...

Anyway...do the rebuild asap...oil is getting danged expensive...I could have put my kids through college with what I've spent on oil over the last 20 years...

Good thing they all went out with the condoms...well, not really a good thing...I hope they didn't meet up with an egg infested tampax in the dump...my children would be garbage dump orphans...wandering around feeding on other people's trash...

 

[swynx]

When i coast going downhill the engine idles like 300-400 rpm higher. Since you said the vacuum is higher during engine braking and my car sucks the oil on hills should i go diwn this hill again after i put in stop leak? Ive used the stp stuff before but it changed nothing

 

[Mark_88]

I've managed to slow down my oil consumption considerably by simply routing the PCV and the valve cover vent to an oil catch can. Most of my oil was being tossed out due to excessive blow-by and by rerouting the pressure to the catch can I've been able to retain oil for much longer than before.

The trick is to make the outlet for the catch can as big as the combined inlets to the can...I had tried to contain the pressure somewhat but it is simply too much for the engine and the oil has to go somewhere...

The bigger challenge now is to find a way to route the pressure back into the engine...I could almost turbo charge my engine with all that pressure...hmmmmm....hmmmmm...HMMMMMMM~

LOL

 

[ZMan]

I've seen a lot of saturns burn oil and blow huge clouds of smoke. I would think valve seals or pcv.

 

[Andy D]

Go over to BITOG and search for Mola-brew. It is a home made solvent that you pour down the spark plug holes and leave in over night to soak the sludge off the oil rings.