Hi,
i have Cooper S R56 2012 that show mutiple misfires , then the car reduces power and can not pass 4000 rpm without any warning light.
Is possible go have limp mode without any warning light (not half engine…nothing)?.
I stop the car, ignition off and on again and everything is normal until it happens randomly again.
Thanks for you comments.

 

It would appear based on what you wrote the engine is in some form of limp mode. if no limp mode warning message then the limp mode is not from the ECU but simply the fact the engine is running so poorly it mimics a limp mode.

Regardless you need to get that misfire condition sorted. Rich misfires can damage the catalytic converter. Even misfires due to other conditions are no fun.

 

Yes, that sort of limp mode is due to something I do not know yet. Glad it looks not coming from the ECU.
During the journey of finding the misfires (multiple misfires, but mainly on cyl 2 and 3), so far I have: changed spark plugs, coils, air filter, fuel filter, oil change, installed oil catch can, changed camshaft sensors, cleaned intake valves. On these two months of misfiring, HPFP and throttle body was changed (not related I think).
I did a comrpession test. All cylinders between 155 and 165 psi. I also did a boroscope, the one you can move 180 degrees to see the valves and all looks ok.
The misfires without any engine light and the limited power (rev stops at 4000 rpm), appears when I lift the gas pedal (not always) or going downhill, so mainly without load.
It looks like air or ignition problem. Vacuum from an injector?.
Engine has 90.000 km.

 

timing chain is all good?

 

I do not know yet. I will check that.
Car runs perfect, idles fines cold/hot, high revs fine…all looks accordingly, but once in a while (not always), misfire and safe mode appears. I believe timing chain should show problems constantly (?).
Thanks for tour advice.

 

@rvidal
You might wanna check your VANOS solenoid on the condition. That can be part of your problem

 

Do you have a code reader to check for any stored codes? If so, what make model. Some will not show all the mini Codes.

Personally, I hate just blindly throwing $$$ and time at it without any idea of what is causing it. I use my phone (Bimmerlink App) and an ODBII Bluetooth adapter or my K DCAN cable with a USB adapter to read/clear codes. If doing that this website "interprets" them. https://bmwfault.codes/. If using a Bluetooth adapter, make sure it is one that is approved. Their app will not work with my cheap China unit but I also had a Veepeak adapter which it worked with. Even if you buy both it is less than $100 spent and you can get a good diagnosis. I know mine has saved me time and $$$.

 

Good point. I forgot to say that I installed new Vanos too (two weeks ago). I put aftermarket with the screen design. No change from the originals.
This weekend I checked both and they are clean. Thanks for your comment.

 

My limited 1st hand experience is with cars fitted with 2 fuel pumps, a HPFP and a low pressure fuel pump, it is often (always but my experience is as I admitted limited) the low pressure fuel pump. One symptom that is common is the engine runs poorly and runs poorly especially at higher RPMs. At least this is what I learned from talking to techs who saw these systems day in and day out.

90km is low miles, err kilometers, for a low pressure fuel pump to fail. But maybe not. Fuel pumps can fail at any time. I had not one but two low pressure fuel pumps in another vehicle fail after just 5K miles of use. The original pump failed and was replaced then about 5K miles later the replacement pump failed and was replaced.

Might add in the case of this vehicle the engine would die and concurrent with this the CEL would come on. Read what codes I could get with a generic OBD2 code reader and the code pointed to a low pressure fuel system problem. The dealer's code reader was able to pull out more codes.

 

Hi, I have a Creator C501. I have not tried the ones you mentioned. My scanner provides a lot of information I think, but the errors I am having are not giving me more details.

Today driving to my office (45 kms) with the scanner, I had the normal package errors when going downhill on third gear close to 2800 rpm: 2EFE (misfire several cylinders, 2F01 (misfire cyl 3) and 2F00 (misfire cyl 3). No engine light, just limited power up to 4000 rpm. I clear the codes while driving and all went back to normal.

Do you think the scanners you mentioned can provide me more details or even hidden codes?. Thanks

 

Not necessarily, I just noticed you didn't list any codes earlier. Sometimes that will help others with your diagnosis.

You might try switching the coil from cylinder 3 to any one of the others and see if the misfire code moves to that cylinder. If so, possibly a bad coil. Otherwise you might look into the vanos solenoids as mentioned above.

 

Good point. I forgot to put the codes on initial post.
Sometimes I also have A559 code.
I changed the coils with new ones and also swap between cylinders. 2 and 3 are still the ones that misfire. I understand 2 and 3 are pair cylinders, so maybe one of them is having the problem, but transmits the effect to the other one. Once in a while I get 1 and 4, which work "together" too.
Vanos are new also. Checked yesterday and looked clean. Thanks

 

BTW, is there any special happening between 2500 and 3000 rpm, which is where normally I have the misfires under little load or going downhill?.

Coming to the office today, I was monitoring O2 Lambda value and Volts (I think is the the one before the CAT). Lambda values when pressing the gas pedal, was always close to 1.0 and increased to 2.0 when lifting the gas pedal only.
I checked Volts O2 sensor values (edit: my scanner does not clearly indicates which O2 sensor is...1 or 2) and showed the following:
- Normal cruising: 0.1 to 0.3V
- Full pedal close to 5000 rpm: between 0.7 upto 0.85V,
- Idle: 0.1 V
I do not know if these are good numbers.

 

In another forum, regarding the safe mode with 4K rpm limits I am having without any engine light, a guy posted:
" At 4K the ECU stops using lambda control for fuelling and instead uses its preset map (target)..."
I do not how if this comment helps to find the diagnosis.

 

It would be interesting to log some data while you were driving. Torque App Pro or Bimmercode.

 

I believe you are not getting the full picture, so to speak.

O2 sensor before the converter, a narrow band sensor, voltage ranges from 0.1V (or a bit less) to 0.7V (or a bit more). At idle the engine controller varies the amount of fuel it injects to be just a little too much -- and we are talking about just a little -- or just a little less. It does this about once a second. The result is the O2 sensor reads an excess of oxygen in the exhaust gas or a shortage of oxygen in the exhaust gas. At higher RPMs this swinging back and forth from lean to rich happens more frequently. With a code reader/data logger it can be hard to get a more complete picture of the voltage swings the #1 O2 sensor experiences. A fuller picture with the voltages plotted would look like a sine wave

Wide band O2 sensor the voltage ranges from < 0.7V to lamba to 4.0V. Lamb is an air/fuel ratio that results in stoichiometric combustion. Wide band sensors provide much more precise fueling.

I can say from experience to catch a bad O2 sensor in the act of being bad is darn hard. With another brand of car I managed but it took some time. Sure I could have just replaced the sensors but I was curious as to what or rather how the sensor was behaving.

Might mention too with some OBD2 code readers one can initiate O2 sensor tests that are supported by the engine controller. I don't know if any MINI engine controllers support these. I know other German cars did -- and used Bosch electronics -- so there's a chance MINI engine controllers have at least some of these tests present.

The engine controller keeps close tabs on sensors. If one was bad the odds are there would be an error code pointing a finger at the sensor.

As for your question about what if anything may be happening at 2500 to 3000 RPMs? I do not have access to that detailed info about the MINI engine. I know with other brands of cars at around 3K a special valve in the intake manifold opened to change the manifold from one conducive to producing torque to one which would provide more HP. And this engine and other engines with variable valve timing this system can change timing at various times. The MINI engines have very active intake valve lift control and I suspect valve timing control. I would not be surprised that one or both of these features is active at 2500 to 3K RPMs. 'course, that is just a maybe... You need to know.

 

Thanks for your input. I agree I do not have the full picture and the information I am getting is poor.
When I started to "fix" the car (just bought it about two months ago and drove for +5000 km so far), I thought it would be easy, but now I realize how many sensors and potential factors without code error can appear in these cars.
I have an appointment to Mini dealer next week, but I would love to find the problem myself for learning purposes. Murphy will probably be there and will not fail the car:-).
I am willing to buy more tools and to spend a reasonable amount of money, to know the car better and to play with it by tuning or anything fun for me and my son who is getting fan of internal combustion cars....before they disappear. This is my first time with Mini and I see a lot of potential for having fun.
I just purchased a OBDX CX scanner and expect to have more real time/graphic information. It takes two weeks to come to Chile. I am also willing to buy a picoscope too but need to read how much it will help me as the symptom normally happens while driving.

I will check if my Creator C501 or the one on its way can do a O2 sensor test.

Today I had several "safe modes without engine light" due to misfiring on cyl 2-3 again and noticed in the scanner that the tank vent valve was closed (I believe 0 value in my scanner is closed?). I do not know if the valve is closed intentionally due to the safe mode or if a closed valve can trigger a safe mode. I cleared the codes by shutting off the engine. Switched on, and the vent valve was reopened.

I also noticed that during the safe mode, besides the 4000 rpm limit and no boost, idle rpm rose to 1000 rpm. It comes down to 800 when clearing the misfiring error codes.

 

An update guys:

With my Creator C501, I could not test the O2 sensors...:-(. I will wait for my new scanner.

Reading here and there, I noticed that diverter valve has something to say in my problem. Diverter valve releases the boost pressure to the intake of the compressor, when the boost is not needed, for example, when lifting your gas pedal like going downhill (which is my case with the misfires). If boost is not released in this case, it can created unneeded pressure at the manifold with potential issues like misfiring. So I order a new DV, unfortunately there is a new model with pistons in stead of diaphragm, but could not find the new model So I installed a new old style and there are some improvements. I drove for more than 80 kms and there were some misfires (sets between 1 and 4, in stead of 50 or 70 as beforei), so I never had the "safe mode without warning" during the test. I think this is good news, however I can not say it is fixed yet.
I also noticed days ago, when I was monitoring pressure sensors (MAP) on intake manifold before and after throttle valve, that both were showing different values, which I believe is a mistake. I think there is an issue here, specially the one after the throttle valve, which I read is the most important for the ECU to lean or to rich mixture together with O2 sensor after the CAT. So I ordered both MAP and waiting for some news asap.

 

I could be wrong but usually when a diverter valve goes bad, it releases boost not retain it.

 

i think a bad DV can do what you said if bad means broken diaphragm. Bad could mean also not to be able to open the piston (bad coil or wrong opening timing), without releasing the boost on time.
Anyway, let’s see how it works the next days. Cheers

 

Anything is possible I guess. With other cars I have observed the engine controller switching from closed loop mode to open loop mode not at a specific RPM but due to the amount of torque demanded by the electronic gas pedal. The engine controller goes open loop and ignores the #2 O2 sensor readings. The engine controller fuels the engine for max power which is richer with an air/fuel ratio of approx. 13:1 rather than the usual leaner 14.7:1 mixture. But it is this leaner mixture that produces exhaust gases were are more efficiently/effectively processed by the converter.

 

Has it worked since changing the diverter valve?

I just replaced mine this last weekend while doing an oil change. I knew I had the old or original style in the car and wanted to update to the new style before it left me with no boost on one of my long trips. I know there was a post somewhere with pictures and descriptions of the new style using a piston instead of a diaphragm but cannot find it.

 

So far, it is working fine. No safe mode so far in three days (quite a record). However the scanner is still showing me several random misfires, but not enough to protect the car by changing to safe mode. Fingers crossed.

This is the old one:

And the new one:

 

Hi, still have the same issue.
After several days I changed the DV, misfires came back again. Time ago was 2 and 3 cylinders and since three weeks, misfires is 1 and 4.
I believed the problem could be mechanical, so I decided to change Stem Valve Seats. While being there I checked first the timing and it looked good.
Nothing improved when first started the engine...it was even worst :-(. I took the car for a hard drive and misfire dissappeared for several days.

Today problem still exists. Car runs perfect in all conditions. Idle, cold hot, high rpm, etc etc...BUT once a day under low load, it misfires (1 and 4 now) and car changes to a kind of safe mode. No check engine light, idle rises to 1000 rpm and can not rev more than 4000 rpm.