So I finally decided to do my oil change and I discovered that I was missing 2.5 quarts of oil. It's been like 10-15k miles since my last one which was done by my dealer (I typically do it myself but I happened to have it in for a leaking thermostat housing - which was causing the water temp gauge to go all the way hot).

I've been using Mobil1 synthetic and I had 40k trouble free miles until doing this oil change at 55k - none of it had ever disappeared (5 quarts always came back). Does the oil used by the dealers burn more easily? I haven't noticed any leaks and my exhaust isn't black and wet, just black since it runs rich. Slightly worried that it could be due to the overheating issue mentioned above.

Any insight on what I should do? Also working on a compacted schedule since I want to get tuned when Jan comes to Austin in two weeks (so if I need to get a head, I need to get it this week).

Thanks in advance

 

Check the crank sensor seal and front crank seal.

 

you want to check oil monthly or there about. 2.5 quarts in 15k may be more than you're comfortable with, but as the rings get more tired, and you develope some of the slow, typical leaks in the engine, it's not that high a leakage rate. What will hurt is if it gets really low and the engine starves for oil.

So as you hunt down the leaks as suggested, just make sure that you do a more regular oil level check.

Matt

 

+1

Not checking your oil enough is a sure way to ruin an engine. I check mine weekly, but at least once a month everyone should open the hood & check all fluids.

 

Sorry to beat you up, but doing 10-15K miles without bothering to check your oil is grounds for reporting you to the Society for Prevention of Cruelty to Engines. 2.5 qts in 15K miles is 1 qt in 6K miles which is completely within the normal range for oil consumption. In fact, Mini will tell you that a consumption rate of SIX TIMES this is acceptable. So the problem here is nothing to do with your engine and completely to do with the lack of attention of the driver.

Count yourself lucky if you haven't caused long-term damage. All you can really do now is monitor consumption more closely and hope for the best.

- Mark

 

So it seems that everybody is leaning more toward the camp that it's just normal oil consumption. I'm just surprised that it went from 0 consumption for 40k miles and then 1qt per 6k miles for the last 15k.

 

One thing to consider when using a different brand of oil is the cylinder wall glaze can be dissolved. This was common back in the old days of big V8's. I would think modern oils would be less likely to do this, but who knows. If this is indeed the case, new glaze will be deposited and the oil consumption will slow.

Kevin

 

Like I said earlier, look at the common placed that Minis leak oil. But none of them are really fast. So to protect yourself, check more often while you hunt it down.

Matt

 

If you are losing a lot of oil, time to get a "For Sale" sign. The consensus is that after 48k miles, you better get out the checkbook because 4 digit repairs bills are in your future. They are only built to last the duration of the factory warranty. Oil loss and burning means internal engine damage.

 

Whose consensus is that??? I have 63K with no oil loss issues & many others have high mileage MINI's without issues. 2.5 quarts over 15K isn't a lot. The real issue is running an engine 2.5 quarts low, not the fact it used the oil.

 

I thought I was burning oil, about .75 qts per 2,500 miles, but my oil pan was always wet and my crank seal was seeping.

After replacing the oil pan gasket and crank seal, I have no oil loss between changes done every 3K miles. And I have over 80K miles on the odom.

 

We really don't know what the consumption was for those 40K miles since I doubt the owner was checking the oil level. Maybe it didn't need any makeup oil between changes, but that can still mean it was a down a qt or so with the changes. (When people say their engines use "no oil" most of the time they are saying that they don't have to add makeup oil between changes which is not truly zero consumption.)

And then there's the high temp excursion that required a thermostat replacement. That could easily be the event that lead to higher rates of consumption. Not so high that there is anything necessarily requiring repair, but it could have been the event that turned this engine from a 1 qt/15K miles consumer to a 2.5 qts/15K miles consumer.

All engines consume oil, some more some less. While engines tend to use more during breakin and after many miles have accumulated with the inevitable bumps/bruises, there are no hard/fast rules. Regardless, 1 qt/6K miles is a normal and reasonable consumption (I'd guess more/less average) so while its always a good idea to check for leaks, I doubt there are any. And this rate of consumption is nowhere near high enough to start looking into engine rebuilds or repairs.

Even an engine that appears not to be using much oil should have the oil checked every month or so, or about every 1K miles. Things can change and the engine may start using more oil. To not do this is owner neglect, pure and simple.

- Mark

 

I agree with markjenn. I've had countless Minis come into the shop with only 2.5 qts of oil in them yet no leaks could be found. After 15,000 (sometimes 20,000+) miles between oil changes it isn't surprising that the oil is that low. The problem comes in when people don't check the oil, premature ring wear and spun bearings can very easily result.

Had a customer a few months back who complained of excessive engine noise. There was only 1/2 quart left in that one. I was shocked that the compression was still up around 180 on all cylinders. Did an oil and filter change and sent him on his way after not finding any leaks. Told him to watch the level more closely. I've seen the car a time or two since and it's still running great with over 100k on it.

 

So I headed up to Austin for the tuning session with Jan but my car ended up having some issues...

1) The car was producing erratic air/fuel ratios (almost as if the fuel delivery system was being stressed and after each run, the A/F would lean out)
2) It seems that that the soot on the tailpipe would denote that my engine was burning oil

Jan ended up not being able to tune my car since it seemed like the fuel delivery system wasn't very stable and with the same map, the car would keep leaning itself out. Jan was great though - after spending two hours on the car, he didn't charge me anything.

Jan postulated that since my car was running lean, the engine was in turn burning oil. He recommended that I test the fuel pressure at the rail (to check if I had a failing fuel pump), and get a compression and leakdown test done.

Will keep ya'll updated. Really disappointed that I wasn't able to get tuned but such is life.

 

there is a rising pressure fuel regulator on the fuel rail. This is the little can shaped thing in the middle of the rail that has a vacuum line running to it. If that is screwing up, fueling will be screwy as well. Something to check.

Matt

 

Okay, so I pulled the plugs and was hoping some of you car gurus could help me out with reading the sparkplugs. These only have 1300 miles on them.

 

with the oil issue. I go through 2 quarts every 7,000. I asked the dealer ship and they say its normal for my car. If you really drive your car hard it really eats that oil.

 

time for a compression test.

 

Could you help me connect the dots?

 

looks like alot of oil deposits and some fouling maybe . so rings would be likely candidate . bring car to stealer or other mechanic and get a compression or leak down test done . how many miles on car? seems odd they'd all be that bad ; unless it's fuel ., but cant smell it from here . if super high miles then could be rings . or if it were run low on oil and rings took a beating . either way a test cant hurt .

 

Going to try to take it in to a mechanic today, but there are no real good mini shops around here and the dealers are a PITA.

The car just broke 55k a couple of weeks ago. If it makes any difference, the majority of my driving during the week is less than 3 miles per trip/start-up - sometimes even less.

Also, if it matters, these sparkplugs should reflect my overfilling of oil. 5 quarts vs. 4.7 quarts.

 

i dont know what other people do but when i change my oil , i fill it to fullthen start it and let the filter fill, then shut it down and check it while the head is full .then add acordingly. so needless to say; i'm running more than factory recomended amount . i believe alot of mini drivers run more than factory amount. i doubt it accounts for the condition of your plugs. the oil would need to get bye the rings and or the valve seals .you'd lose a bearing first from foaming probably .

 

You're probably not overfilling by much - the drainback from the head to the sump is pretty quick (95% within 30 seconds or so). Why you think overfilling is good is beyond me also.

- Mark

 

never said i thought it was "good" . just that if not by much than not harmful on these cars. many have determined a half quart to be resonable overfill . seems minis a prone to starvation at speed in turns . some use baffles in pan and others overfill a bit .

 

Got the leakdown test done - 3-4% across the board. I told them my tale and they recommended that I change out the fuel filter - scheduled for next week. I'm not sure what the next step is now... Anybody? Anybody? Bueller? Bueller?