Oil Consumption

[Keith Tedford]

I don't know about the new stuff but in the old days, with the chromed rings, load the engine to get the rings to seat properly. You can get onto it but just don't make 6500 rpm runs. Be sensible. Babying the car and chances were good that the rings were not going to seat any time soon. Our '05 had about 13K miles on it when we bought the car. It uses perhaps a pint in 5K miles.

 

[JB08]

I followed the break-in procedure and was careful not to rev the car too much in the beginning. Now I will confess to having hit red line cut-off a couple of times when merging with traffic, so I have not really babied the car since either... probably like most people, a few spirited drives with mostly casual cruises. The funny thing is as someone noted earlier, where is this oil going? No leaks on my garage floor, no black smoke or other evidence of burning and no goop on the exhaust tips. I do clean the exhaust tips regularly as they do get dirty with soot, but I don't think it's anything out of the ordinary...?!? I have followed the manual religiously and make sure the engine is at least 85c and wait to between 5-10 minutes to get a reading, so I don't think I'm getting false readings either... oil pressure is normal (usually at mid level or below) and engine and oil temperature are also in the normal mid-range.
Re: modern engines, yes it's rare, but I saw this in my search for possible causes:
http://www.consumerreports.org/cro/magazine/2015/06/excessive-oil-consumption/index.htm

 

[tyho]

Ok, so I checked last night after driving about 30 km. I let the car cool off for about 7 minutes. The oil level was the same as when I checked it cold. I don't see any oil reduction happening. I'm certainly not an expert when it comes to mechanics, but I have read that catch cans (not exactly sure what they are and how they work) accumulate oil and reduce it from entering the air intake, if I interpret that correctly. Maybe this is something to look into???? Otherwise I would say it is being burned off somehow if there are no leaks. Sorry I couldn't offer more assistance. Good luck.

 

[smackYYZ]

Last oil change was at 7,160 km, have 9,300 on it now. Just checked my oil and was down. Took a full litre to bring it to the middle of the hash marks. A litre in 2200 km seems to be a bit high.

Maybe unrelated, but I've also noticed some oil build up on my exhaust tips, so now considering a catch can.

 

[C7Driver]

I don't have a dry sump, my car has never used any oil. We did a trip from SW Ontario to the east coast and back in June and didn't use a drop. I have 14k on the car now and check the oil levels often, oil changed twice but never added a drop beyond the oil change. Each time the oil was changed the stick level was where it started at. Your usage seems high to me.

 

[C7Driver]

Maybe unrelated, but I've also noticed some oil build up on my exhaust tips, so now considering a catch can.

You have oil on your exhaust tips? That would seem very strange, you might get some carbon on the tips which is normal but never oil. I had a S/C car before the C7 and it ran rich , lots of carbon on the tips compared to this one.

I have a friend who put a catch can 4 yrs ago on a his turbo GM engine, not a drop of oil in it ever. He was up for a visit last weekend and I asked him again, he said no oil in it, none in his turbo he keeps a close eye on it, feels like he wasted his money on the catch can. I have a 5 yr old GMC Acadia which has a direct inject engine, checked the air intake a number of times , no oil what so ever. With as many engines as GM produces that are direct injection, it's been more than 10 yrs since introduced, it would seem illogical that they would not have had a issue already show up. I'm skeptical of the need for a catch can, perhaps some drive their cars harder and it creates an issue with "burps". If you drive a car hard consistently you will need more than a catch can over the longer term.

 

[smackYYZ]

You have oil on your exhaust tips? That would seem very strange, you might get some carbon on the tips which is normal but never oil. I had a S/C car before the C7 and it ran rich , lots of carbon on the tips compared to this one.

Before I'd noticed just some carbon build up on the tips, but last weekend when I washed the car I noticed at the bottom of each tip a bit of black goo, not hardened or dry like the carbon build up but more tar like. And before I didn't burn through a litre of oil either. This weekend going to take the car for a good run, and will see what is on the tips.

Also going to keep a close eye on it and see if the oil consumption continues.

 

[JB08]

Update - So I've had the car out for a few weeks and I've managed to put 2,500 Kms on it since the last oil change in late September, about a month before I put the car away. Just checked the oil and it was down below the recommended level. I added one quart and it brought the level back up to just below the middle of the hash mark area on the dip stick. So it looks like consumption is about 1qt per 2,500Km, which is an improvement over what looked like 1qt per 1500KM. Now, I'm currently being a lot more careful to measure and look at the kms and oil amount I'm adding in so that I get a real precise measurement. The dealer had told me to go in and get the oil added at the dealership so that they could track the consumption. But besides this being a pain, I want to have a really good idea of what is happening before they tell me what they see. With the warranty at 5yrs and 150,000KM I'm not in too much of a rush to let them go tearing into the engine before I understand the severity of the issue. Besides, I suspect that this level of consumption is probably within GM's specs, even if it sounds high for most drivers. I understand from a member at the US forum, that GM has a bulletin out recommending that cars with high oil consumption have their valves replaced. He had this repair done and his consumption is now 1/4-1/2 quart per 1000 mi (or 1qt per 2000Km) which GM claims is within spec. So, it looks like I would fall within that threshold anyway and would be facing an uphill battle for any redress.

I would be interested to know from those of you with more engine knowledge if there are reasons why consumption would decrease over time (since usually the opposite is more likely). Thanks.

 

[AllFlash]

Odd. I am on my 5th oil change (just done) and have 25,000 km on the car and have yet to notice any oil issues whatsoever. If you are consuming that much oil, it has to be evident somewhere. If you are keeping an eye on your exhaust, remember that the spring temp changes will result in additional moisture and soot from the pipes. If you are seeing blue smoke or that moisture doesn't dry and seems oily, you might start looking at valves but that isn't likely with your car I wouldn't think. How many km?

 

[JB08]

I'm at 15,400Km. No evidence of any oil anywhere, except for some soot on the outer exhaust pipes (I keep the exhaust in track setting). I don't think my exhaust is any dirtier than other C7's I've seen. No evidence on the garage floor of any leaks which would be obvious after the car sat for 3 months.

 

[CCO]

Update - So I've had the car out for a few weeks and I've managed to put 2,500 Kms on it since the last oil change in late September, about a month before I put the car away. Just checked the oil and it was down below the recommended level. I added one quart and it brought the level back up to just below the middle of the hash mark area on the dip stick. So it looks like consumption is about 1qt per 2,500Km, which is an improvement over what looked like 1qt per 1500KM. Now, I'm currently being a lot more careful to measure and look at the kms and oil amount I'm adding in so that I get a real precise measurement. The dealer had told me to go in and get the oil added at the dealership so that they could track the consumption. But besides this being a pain, I want to have a really good idea of what is happening before they tell me what they see. With the warranty at 5yrs and 150,000KM I'm not in too much of a rush to let them go tearing into the engine before I understand the severity of the issue. Besides, I suspect that this level of consumption is probably within GM's specs, even if it sounds high for most drivers. I understand from a member at the US forum, that GM has a bulletin out recommending that cars with high oil consumption have their valves replaced. He had this repair done and his consumption is now 1/4-1/2 quart per 1000 mi (or 1qt per 2000Km) which GM claims is within spec. So, it looks like I would fall within that threshold anyway and would be facing an uphill battle for any redress.

I would be interested to know from those of you with more engine knowledge if there are reasons why consumption would decrease over time (since usually the opposite is more likely). Thanks.

Oil consumption varies from engine to engine as you know......I believe you to be correct when you say that your engine's consumption is within GM's specs.-- Whether yours is excessive or not is a matter of opinion.......As we all know there is always some consumption -- most of which is not noticeable -- but engines vary somewhat causing increased consumption. GM's guidelines are what? : consumption in excess of a quart/liter in 1500km warrants repair?

I think you've hit the nail on the head saying that your consumption isn't excessive at the moment (pending final confirmation) ....... and that you need to calculate consumption closely now at least to get a baseline. The dealer will want to be involved in this process and if it were me I'd let them be involved.-- probably a requirement from GM.
That way if consumption worsens (or improves) then you'll know about it quickly.

As to whether consumption on a new engine may improve with age -- I would say it might as the engine parts such as rings and valves 'seat in' properly which can take a few thousand kilometers.

If it were my car I'd watch the oil level closely just as you are doing.......allow the dealer to fill or maintain your oil and monitor for any consumption to determine the exact issue.

BTW -- to my mind the level "just below the middle of the hash marks" is down perhaps half a liter (at least on other vehicles I've owned)....so you may want to fill to the top of the hash marks to get benefit of a 'full crankcase'.
Be careful to not overfill tho. This apparently can cause foaming which then gets pumped into the oiling system.
I find checking levels the morning after using the car and topping up as needed then. That way all the oil has had a chance to drain back into the crankcase. Be sure the garage is level.

I does sound like GM is aware of the issues and is prepared to help should your engine consume excessively.
There will be other tests involved with their evaluation such as cylinder compression (wet and dry) to help them diagnose the problem.

The "soot" you mentioned is probably an accumulation from slow(er) in-town type driving. It should disappear when the car is driven on a long trip steady speed. -- and yes as Keith mentioned b4: don't be afraid to make the engine 'work' -- that's what they're built for.
I would avoid excessive 'red-lining' tho as also mentioned.

I would also get that bulletin info you mentioned about. It may be handy if the dealer knows little about the problem. Google could also be your friend if you haven't already.

Keep us apprised and GL.

Colin.

 

[CCO]

I"ve just done a little research myself and found that your dry sump system requires a different procedure for checking oil levels. It mentions about bringing the engine up to temp -- then checking ..... so checking in the morning cold will not work.
Having a full crankcase (specified 'full' level') to me tho is important. since there may be a liter difference between the hash marks.

I googled the issue and found very little to refer to also.

C.

 

[JB08]

I"ve just done a little research myself and found that your dry sump system requires a different procedure for checking oil levels. It mentions about bringing the engine up to temp -- then checking ..... so checking in the morning cold will not work.
Having a full crankcase (specified 'full' level') to me tho is important. since there may be a liter difference between the hash marks.

I googled the issue and found very little to refer to also.

C.

Thanks for the feedback... yeah, I have no issues with getting the dealer involved, but I want to my own data before I engage them.

 

[theboss]

Good morning and happy Easter to everyone. As I was readind the entire thread, it remind me the problem my fishing parter encounter with is Grand Caravan 2007 with a 3.8 V6 engine, is fourth Caravan (he have 4 kids). He is the kind of guy who open the hood to put winshield washer and that's it. He take is truck to my shop every 5000km and have the oil change, on the 2007, at about 2000km the oil lamp came on on the highway, he took the first exit, stop at the gaz bar and found out he was missing 3.5L of oil. He tought the engine wasn't fill properly at the delivery inspection so he refilled it and continue his trip. After another 1500km, he decided to check again, it was missing another 2L. Took it the dealer, they changed the oil and started a oil consumption test and they found out the truck was using 1L every 1000km but Chysler's spec said sucking oil to a level of 1L for 800km was normal. Funny as the 3 other Caravan before had the same engine without oil consumption ??? He had the truck 2 year and had to carry a 5 liter jug in the back for refils. At 20000km I removed the spark plugs to check if there was deposit on them and there was a lot of it. I did showed the dealer the plugs but they stoud behind the 1L/800km..

On my 16000km LS9, I check the oil often and it never had used drop yet. I suggest you check the spark plugs for deposit, may show some evidence of a problem. Personnely, I find a 1L/2000km on a modern engine that is suppose to be a clean engine should not burn that much oil. My courtesy car (Yaris 2009) have 250000km doesn't burn a teaspoon of oil between oil change.

Good luck Stephane

 

[Riley P]

That is a lot of oil! 1L/800km normal??? So on the highway, basically every fill up would require a $6 liter of oil. Yikes! At least the muffler bearings would remain well lubed!

As stated earlier, as the rings/valves seat, the consumption should go down on a modern engine, however, it shouldn't take too long for this to happen. Hopefully they find the cause and can get you on the way with using less oil.