Burning Oil

[RoGuE]

I have been burning oil for a while now. I never see it on the driveway. I have even had the Low Oil message come on before. Just before I checked the oil and it is only 1/4 of an inch up on the dipstick. I poured in a full quart and it filled up 3 out of the 5 holes on the dipstick. I have only gone 2700 miles and about 2 3/4 months since my last oil change. Is this a cause for concern?

 

I have the 5.3L engine in my 2002 Suburban.

[ken1mod]

try a thicker oil.

 

ken

[CapitalTruck]

Bring the thing up to full and check it every week just to see what is going on. Remember, the full distance between the bottom hole and the top hole is 1 qt.

[frdfandc]

You might want to give your dealer a call reguarding oil consumption. All manufacturers have allowable guidelines reguarding oil consumption.

 

When I worked for a Ford dealer, guidelines were 800-1400 miles per qt of oil. The guidelines for Hondas (yes I worked there too) were 600-1200 miles per qt of oil for the older cars, and were 800-1200 miles per qt for the newer cars. But most cars only used approx 1 qt of oil every 3k.

 

I wouldn't be too surprised if GM's allowable oil consumption would be in the 800-1400 mile range either per qt of oil consumed.

[RoGuE]

So this is normal? What causes oil consumption? Where does it go because I never see blue smoke out of the tailpipe.

[Axlshaft]

I'm not sure if this will help or not but I had the same problem on my '95 Sierra 5.0L. It started using oil at about 45k, about 2.5 qts every 3000 mi.

The dealer insisted it was gaskets even though there was never any evidence of leaking on the ground. They put the dye in the motor and over the next 6 months preceded to replace almost every gasket on the motor.

I insisted it was burning, but there was no blue smoke. The extended warranty ran out before the problem was solved.

I figured it was the exhaust seals cause right when you started it up you could smell hot oil out the tail pipe, just on start up. I put some slick 50 in the oil and the problem went away. Even now at 170k it only uses about 1/2 qt in 3000 mi.

[ken1mod]

With all the hot parts banging and sliding around in the engine, I think it is amazing that engines don't burn more oil than they do. Most modern engines don't burn excessive oil until they are overheated and the rings stick. Working engines in airplanes and heavy equipment burn significant oil, aircraft engines can burn a qt every 2 hours and still be considered perfectly healthy.

 

My sense of humor in vehicles ends somewhere around a qt per thousand miles. If you are in the 3000 mile range, don't worry. You definitely might consider a different brand of oil and a slightly heavier oil.

 

Ken

[Dux-n-Dawgs]

My wife's '99 Tahoe 4x4 has a Vortec 350 in it. It was putting Castrol 10w-30 in it until it started useing more oil than I liked at around 85K ........ I switched to Castrol 15w-40 and it burns practically no oil every 3000miles and she's sitting near 159K now.

 

So I second the 'try a heavier oil' idea.

 

-Dux

[RoGuE]

What kind of oil is recomended for this engine? I have been using 5w-30. Could that be the problem?

[frdfandc]

Recommended oil is 5w30. And since you are only using just less than 1 qt per 3k, if it were me, I wouldn't change anything. But since you are worried, you could try and step up to a 10w30 and see if it changes.

 

 

 

Oil is going to burn reguardless of what engine you have. Some just more than others. You have to think that the cylinder walls are coated with a film of oil to allow the pistons to move up and down slowly, but at the same time, you have the combustion process happening in the same place. So oil will burn when the air/fuel mixture is ignited.

 

If the consumption is alot, that is when you will see blue smoke out the tailpipe. But if its very minimal, like yours, it burns that qt over a period of time, you will not see any blue smoke out the tailpipe.

[C & A s Dad]

Jonathen, you did not say how many miles were on your Burban?

 

I would also tell you to check the PCV valve. If it came with the fixed orfice style, you need to be sure that is what is in it now. If it has been replaced with a check valve design, that could be your problem. I am no expert but I have read posts concerning this.In fact, I believe there is a TSB from GM on this but I am not sure. The PCV valve is located at the rear of the engine on the drivers side.

 

I would not be too concerned but I can tell you that oil consumption with a 5.3 is not common. I have seen many of them with over 200K with no oil burning at all.

 

I would be interested to know what you find out with the PCV valve.

[crazymjb]

I had my 350 swapped out for a new one due to a defect about 90K miles ago by the previous owner and I burn NO oil between changes... Those dealer guidelines are surprisingly high, at least to me. We have had many high mileage cars, and never had a problem with oil burning.

 

Mike

[rjirvine]

Good call on the PCV Valve, Here's a good article on the subject!

 

http://www.mightyautoparts.com/pdf/articles/tt122.pdf

[RoGuE]

I have 64700 miles on the car. The PCV has never been changed according to the records. Should I try changing it and see what happens?

 

Also, could someone provide a picture of where the PCV is? I can't find it on the drivers side.

[C & A s Dad]

Jonathan, look at the very back of the valve cover on the driver's side. You will see a vacuum hose running to it. The PCV valve itself will be plugged into a grommet into the valve cover. It will be about 1 & 1/2 inches long and about 3/4" in dia. where it plugs into the valve cover. If it has a check ball in it and rattles when you shake it is it not a fixed orfice PCV valve like the OE unit. If you see a small hole in the bottom and can see all the way through it or can blow through it is a fixed orfice style and is ok. If it is plugged, (not likely) then you have likely found your issue.

 

A bad or plugged PCV valve can make one use oil and you will never see any smoke to go with it.

 

Let us know what you find when you check it out.