'00 C5 coupe, 54k miles using oil! About 1/2 qt every 500 miles. No smoke on start up or acceleration. Tail pipes relatively clean. ?????????????????????

 

Check the PCV line and see if it's oil soaked. At 1000 mi/qt. use rate there must be something going on.

Is this a car you just purchased, or have you had it awhile?

 

Had it for a year and put 5k on it.

 

Did you notice this all of the sudden ? What is in your oil catch can?http://www.mikenorrismotorsports.com...atch_Cans.html

Automatic or 6spd?http://www.rjsmith.com/gm-894549.html

How much oil are you putting with oil change 6.5 or 7 quarts?
Pull a couple of spark plugs and check for color.
Check the throttle body for oil. Check the rear of the body for oil residue. Pull the PVC hose off and check for oil.

 

You might want to consider running a differential compression test on the engine. This can identify if you have a cylinder that different from the others and if it is a piston related issue, like bad rings. Have you check your coolant for signs of oil, could be a bad head gasket? Let us know what you find.

Eric D

 

What weight oil are you using?

 

How is the coolant temperature? Is it normal (190 F on DIC) or is it running cold? e.g. non-stock or no thermostat...

Oddly enough, a too cool running engine can increase oil consumption (happened on my DD 96 camry v6) -- presume because block/piston/rings do not mate correctly allowing either oil to be sucked in or blow-by to push the oil out and into the PCV system or via leaks.

 

I thought the '00's had ring issues. Did the previous owner have problems with burning oil?

 

No issues with my 2000 coupe. No measurable oil use between oil changes. It has over 42K miles on it.

Eric D

 

stingray1019; help us out here (1) you've had the car for 5000 miles, correct? Did the oil consumption happen all of the sudden? or has this been the normal oil consumption since you've had the car?

(2) No external leaks , correct?
(3) How does the engine run? does it have a miss? have you looked at any spark plugs for carbon? or check the PVC hose for oil, or the throttle body for oil?
(4) Is there a wet carbon residue in your pipes ( I'm trying not to be too personal here, ) If your Tpipes have a wet residue its oil If there is a heavy soot build up that would be an indicator for fuel and to check #3.
(5) Not sure where you are located or if this is a DD, but if your engine temperature does not rise to operating temperature the piston/ring/cylinder bore tolerance is slightly OT. But this would have to be extreme and your car would run fuel rich as well.
(6) Do have any codes? Using a 1 quart every 1000 miles would foul both your O2 sensors and your CAT converters over that amount of time. Visually check one or both of the O2 sensors. If the O2 sensor is fouled it may still function ( but gets lazy) and not cause a code.
Are you required to have emissions testing? If so, when was the last time that YOU had it done ( not the sellers emissions test)?
( 7) do you keep track of your MPG. A fouled or lazy O2 sensor will affect fuel mixture.
(8) the viscosity of the oil should not be a problem being that 5W30 is called for from GM and the oil can't get much thinner unless you have switched to 0W20 ( which is doubtful).

Yes the 2000 LS1 had oil consumption complaints ( as per GM 894549/http://www.rjsmith.com/gm-894549.html )But most complaints came from manual transmission vehicles.

You have make no mention of poor engine responce or performance, so this should be easy to find the source of the consumption problem.

 

The engine runs strong - no leaks - mpg is great (20 city - 29 hwy) - coolant temp is normal - tail pipes are relatively clean, it has been cool here in Omaha so I get a lot of condensation - using 5W-30 Mobil 1 synthetic - no codes - Have not checked plugs. Thank you for all the input and will take any future info.

 

I was driving my '03 Z 2 days ago and the same thing happened! I got a Low Oil message on the cluster screen! WTF?!

I have had the car since last Christmas and have driven it about 5K miles. Had the oil changed once when sensor indicated no life left - done at Andy's A&A Corvettes in Oxnard, CA. I'm sure they know what they are doing, however I do not know what amount of oil they used.

Checked under the car and tailpipes - nothing. When I first got it, there was some oil on the rear crossmember, but the tranny had just been rebuilt and I took it back to the company that did the work. They re-sealed 2 of the bolts with a different product, and that cleared up the couple of small drips I found under the rear. I have not checked the crowwmember again, but will look under the car today.

Car passed Smog Test at time of sale. It has been relatively hot in SoCal recently. Car seems to run strong, but I'm relatively new to this ride and my butt has been more calibrated to my '03 Cobra. I have taken it relatively easy in this car, as it drives completely different from the Cobra and has much more torque.

Ran to Kragen and bought a quart of Mobil 1 5W30 and added it. Message went away - drove home and let it cool and drip down to get an accurate dipstick reading. Showed approx. 1/4 qt over FULL mark.

FEELS like it was maybe just a little under-filled, but I'll be checking the dipstick REGULARLY for a while to get more data on the rate of loss.

All advice gladly accepted. Thanks in advance.

 

Doesn't sound like the oil was actually low, so I'd check the connector on the oil level sensor and make sure it's not loose. Could be the oil level sensor is getting flakI like checking my oil in the mornings when the car is cold ... much easier to see the oil level on the dipsitck, especially when the oil is clean.

 

Amen, only in the morning on a cold engine to be 100% accurate.

 

My 2000 was among the unfortunate few - problem was solved by replacing rings and a few pistons - when tear-down revealed 5 out of 8 only had one compression ring instead of two - after about 40K - the rings that were there had worn enough to cause blow by - mainly under WOT - it would acutally push the oil out the dipstick on onto the header pipe causing smoke - that was the first time I noticed it.
This may nor may not be an issue with yours - but hought I'd throw it in...

 

Thank god mine is not that bad. It is scheduled to go in for a compression test and probably replace rings.

 

Still no puddle underneath and pipes look very clean. Hope it was just an underfill.

I recall that my Cobra used a small amount of oil after I changed it over to Mobil 1 - like 1/2 qt every 5K miles (at oil changes). Someone explained that 5 weight is so thin that a certain amount will remain on the cylinder walls upon start up and that could be the cause of some small amount going out the talipipe.

I have no idea is this notion is correct or not. Any ideas?