Oil consumption got worse. Not sure what to do. Should I sell the car?

[UnhandledException]

Did you buy your M5 new, also? If every high-revving engine you own has consumption issues, there could be a problem with your approach to break-in.

Re. catch can, there are thousands of Voodoos running around with catch cans with no consumption issues. If it was related to the cans you installed, it would most likely be an installation issue and/or a failure with the unit you installed. I still maintain you were creating some kind of siphon effect to pull oil out of the crankcase. Failed oil separator diaphragms on some cars (BMW M54 and M62 engines, for example) can do the same.


What is the purpose of engine braking? Driving the car hard doesn't require engine braking from high RPM. That can create high vacuum that's likely to pull oil past the rings, especially if the rings weren't seated well during break-in. On track, you run the engine hard but you slow the car with the brakes, which exist for that purpose.

I'm at ~3500 miles, mix of highway, hard street running, virtually no city miles, and track. I have consumed about 1/4-qt of oil total.

I bought all these cars new. I babied the M3 and M5 and followed the break in to the letter from the manual. With the shelby I didnt. The first 50 miles I kept it around 4000. Then took it to 6000 a few times till 150 miles and from that point on 1000 more every 50 miles. I hit 8250 by 250 miles. But I didnt redline it off the lot with 5 miles. Should I have done that?

With the way I drive, just in general, I tend to hold low gear so that I can accelerate quickly if the need arises. But I have been changing that or trying at least in the last 1500 miles. But I m not like the other poster, I dont bounce it off the limiter on a daily basis.

Its hard not to accelerate to 4000 rpm and let go off the gas just to hear the engine. Its addictive to be honest.

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[UnhandledException]

Hmm I'm theory the oil could help reduce blow by

That is my point but I m clearly not the expert.

 

[SVTinAR]

An ounce of oil in the separator over 750 miles sounds actually minimal to me based on my 12 GT and the 500 or so miles I've put on my GT350. Both deposited quite a bit of oil in the separator and so far I'm not under the impression my 350 is consuming much oil - still a bit early to know for sure.

Some engines are strange - I have a separator on the pass side of my Lightning PU and it never collects any oil. I have no idea why.

 

[oldbmwfan]

That is my point but I m clearly not the expert.

I'm not sure how that would work. Without a separator, the oil entering the intake is a vapor that is getting burned off in consumption; it isn't running back down into the crankcase. The separator allows the vapor to condense and collect. In some cars, they drain back to the crankcase via a check valve so they are zero-maintenance.

Re. break-in, I am a believer that the gentle break-in per the manual on most cars is a bad idea. It is safe, but it doesn't optimize engine performance or longevity. It prevents the risk of near-term warranty issues, which is what the manufacturer cares about. The manufacturer does not care so much if your power is a few % lower, your oil consumption a few % higher, or your long-term durability a few % reduced.

I posted a detailed write-up of my break-in procedure elsewhere in this thread, I believe. The most critical thing is never running at high RPM with low load (i.e., be at full throttle), and never letting sustained heat build up (i.e., do short hard bursts followed by easy driving to cool down and avoid local hot-spots). Seat rings under pressure and prevent glazing from local overheating.

I doubt the manufacturing process is so variable that it would be normal to see consumption distribution from "no oil consumed" to ">1 qt/750 miles". What is far more variable is driver behavior. The existence of thousands of motors assembled under the same conditions WITHOUT excessive consumption suggests it can be avoided.

 

[UAmach1]

I'm not sure how that would work. Without a separator, the oil entering the intake is a vapor that is getting burned off in consumption; it isn't running back down into the crankcase. The separator allows the vapor to condense and collect. In some cars, they drain back to the crankcase via a check valve so they are zero-maintenance.

Re. break-in, I am a believer that the gentle break-in per the manual on most cars is a bad idea. It is safe, but it doesn't optimize engine performance or longevity. It prevents the risk of near-term warranty issues, which is what the manufacturer cares about. The manufacturer does not care so much if your power is a few % lower, your oil consumption a few % higher, or your long-term durability a few % reduced.

I posted a detailed write-up of my break-in procedure elsewhere in this thread, I believe. The most critical thing is never running at high RPM with low load (i.e., be at full throttle), and never letting sustained heat build up (i.e., do short hard bursts followed by easy driving to cool down and avoid local hot-spots). Seat rings under pressure and prevent glazing from local overheating.

I doubt the manufacturing process is so variable that it would be normal to see consumption distribution from "no oil consumed" to ">1 qt/750 miles". What is far more variable is driver behavior. The existence of thousands of motors assembled under the same conditions WITHOUT excessive consumption suggests it can be avoided.

Could the system be causing extra suction for some reason?

 

[Houston Kid]

What is the purpose of engine braking? Driving the car hard doesn't require engine braking from high RPM. That can create high vacuum that's likely to pull oil past the rings, especially if the rings weren't seated well during break-in. On track, you run the engine hard but you slow the car with the brakes, which exist for that purpose.

I'm at ~3500 miles, mix of highway, hard street running, virtually no city miles, and track. I have consumed about 1/4-qt of oil total.

It’s fun and makes nice sounds and apparently could contribute some to oil consumption. For the next 1,000 miles I will do zero down shifting and see how the consumption changes.

 

[mustang1]

the spark plugs should indicate what is "normal". From the Offboost post, drive the car out to 10,000 miles, and then change the spark plugs. That should give you enough info on whether to push for warranty work or buy an extended warranty.

Offboost
FYI from BMW
"Once a new or remanufactured engine has accumulated 10,000 miles ...

 

[Tomster]

13,000 miles. No track history. Daily driver. Occassional 7-8k rpm. Broken in properly. Never hard on gas when cold. Oil changes every 3000 miles.

The top offs started as 1/2 qt every 750 miles then became 500 miles, then 1 qt every 500 miles and as of two days ago I had to add 2 full quarts in 600 miles (and after adding 2 full qt, the oil level is mid way between min and max).

I have UPR catch can that always fills up and I get 4 oz of oil every 500 miles without exception.

All measurements done on level ground (on my 4 post lift which has level runways). All measurements done after the car was driven and oil reaches 200F and waiting 15 minutes).

The car has a lot of sentimental value for me, my 6 year old loves it. I was planning to keep it in the family and hand her the keys one day. But I m afraid its a dudd and this oil consumption is only going to get worse.

Changing the engine is not an option. A) I dont trust the service. I live in tri state area where Ford service is terrible. B) Not going to be okay with blank VIN stamp on the block.

Is there anything I can do to improve the situation? Should I try different oil? Or should I change sensors somewhere?

Yes, you should sell the car MCarsfan

 

[catdog]

treat it with TriboTex

 

[JAJ]

So an update:

1424 miles since my oil change. I added no oil yet. At 761 miles I re-added the catch can except that adapter that replaced the PCV valve.

The dipstick now reads a mm or so above the MIN hole. If I had to guess, I can drive maybe another 150-200 miles before it will go below the hole meaning 1700 miles for 1 quart.

I also collected about 1 oz of oil in the catch can in those 761 miles. Is this normal? I am beginning to think the oil going back to the engine is not so bad and this catch can is simply causing more oil consumption in general. Maybe that oil going back via intake is helping seal things? Not sure.

I have also noticed that the OUT/CLEAN hose to the intake from the catch can has oil in it. Isn't that hose supposed to be dry?

This thing is driving me crazy. I don't know if 1 oz in 761 miles is normal. I wasn't driving crazy like I always do. I didn't take it easy yes but I didn't bounce the car off the limiter all the time.

I will attach some pictures shortly of the hose and my install.

Let's come at this a different way. The catch can isn't collecting much oil. Most likely, that's because there isn't much oil to collect on this particular car. Oil in the catch can is mist that comes out of the crankcase and for some reason this engine isn't making a lot of it.

Oil consumption results from a number of factors, one of which is oil coming though the PCV system, but most of it is oil that is burned off the cylinder walls or the the valve stems. Engines with low-tension rings (BMW S engines and the Voodoo) will have more consumption than a normal engine. The OP's 1700 miles per quart is fine. There's nothing to complain about.

My point is that putting on a catch can won't reduce oil consumption. The main reason to install a catch can is to keep large amounts oil out of the intake when you're running at high RPM and full throttle with high lateral G's for extended periods of time. FP recommends them for track work but leaves them off otherwise.

So, if the catch can isn't catching much oil, then take it off, drive the car any way you want and check the oil a couple of times a month. All will be well.

 

[Shadow277]

how much would you sell it for?

 

[UnhandledException]

how much would you sell it for?

I wont sell it. Its still with me after 60,000 miles.

 

[Biggus Dickus]

Holy resurrection Batman!

 

[GT Pony]

Holy resurrection Batman!

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