My '05 MCS has been pinging under heavy load with the AC on since new. Tried different California gas stations and found the car ran better on some than others. None eliminated the pinging. Finally decided to take the car to the dealer. After several tries, the tech managed to reproduce the problem. While investigating the pinging, the tech pulled the plugs and found they were dark. So, it looks like I have a nearly new car (4k miles) that pings and runs rich. My guess is the dark plugs are a result of the ECU sensing the pinging and dumping tons of fuel into the clyinders in an attempt to cool them.

The service tech has told me there is not much they can do because the programing of the ECU is what it is. He reflashed the ECU and asked that I drive the car for a couple of weeks to see if the problem is eliminated. Before anyone suggests I switch to colder plugs, please know that the dark plugs were colder (Densos). So, I am kind of at a loss. I know I could fix this through a Unichip or possibly MTH. But, I do not think I should have to pay for a fix.

Any other ideas on this would be appreciated.

Thanks

 

I have heard that this happens with alot of the 05 cars. aftermarket software would clear it up but I think you should find a bunch of people who have the same issue and go to mini usa to see if they can get a new software update.

 

I would bet you have an engine sensor that is out of calibaration. The ECM can only work with info it receives. Since everyone else doesn't have this problem, I would be looking for a bad sensor, MAP, IAT, O2.
Many of these sensors are overlooked because they don't show up as defective, yet they are out of whack enough to cause problems like you are seeing. The dealer should take readings and try replacing the sensors that provide the ECM with info instead of blaming it on software that works fine for everyone else..

 

The temperature of the plug determines how fast it can burn the crap off of the insulator.

If you have dark plugs, then you are running rich, and colder plugs will foul.

Hotter plugs let the insulator get hotter. Yes if they are TOO hot they will contribute to Ping, but that does not sound like your problem.

JD

 

What exactly does it sound like and are there any other tell tale signs?
also what colour are the plugs if it is pinging?
I have a set of Denso IK22's installed

 

PreIGNition; is when for some reason the fuel charge burns, prior to the spark plug firing.

In the cars I have had that did it, sounded like some one knocking on the inside of the engine with a hammer. It is also known as knock.

I had a Comet, (6 cylinder, 1970's Ford Maverick) that sounded like some one had added steel marbles to the engine, every time I accelerated hard at low rpm's.

In modern engines, knock sensors attatched to the engine block "hear" that sound and report it to the engine computer.

My understanding of combustion is below. There may be other opinions.

Several different things can cause Ping. A hot spot in the engine, (such as too hot a plug, or carbon build up, or an exposed edge of the head gasket), ignition too far advanced or too much compression for the octane rating of the gasoline, or running too lean. There may be other causes.

None of the above would change the color of the plugs, except consistently running lean.

Modern ECU controlled engines will try to control the ping by backing off on the timing or throttle position, or adding enough fuel to make the engine rich, and therefore the charge will burn slower. I agree with the prior post, that if the ECU was constantly adding excess fuel the plugs would be a darker color than normal.

John

 

A malfunctioning EGR can also cause ping and severe hesitation. I had this problem on an older Pontiac.

 

Hmm, this isn't quite the same, I have no knocking, but due to the Mini software issues with the 05 MCSas I know my car had been running rich from the beginning. So, based on what you guys are saying, when they do the software update they really should be replacing the plugs as well due to build up? Anything else that would/could be affected and should be changed from running rich for awhile? (I'm running cali gas too by the way.)

Thanks in advance for any help

And to address the orginal poster, as part of trying to have Mini fix the problem I'd put the stock plugs back in, see if its still pinging, and then if is, take it to another dealer. Not all dealers are equal and perhaps the next place will have a better solution/more experience with the issue.

Best of luck

 

Here is the latest.

Not surpsingly, still pinging after the reflash. As before, only doing it after the engine is warmed up, when the a/c is on and the car is under a load (slight grade).

Called the dealer and ordered the JCW plugs. Also told them I want all the sensors replaced. I think they will agree. Hopefully it will turn out that one of the sensors is bad or just out of calibration. Would love to know what you all think I should do next if this does not work.

Thanks, Adam

 

Octaine booster works for me. Outlaw four packs add about $2.50 per tank. Now I don't have any pinging even in 100 degree heat.

 

I used some ocatane booster in one of my cars recently. Later I was reading about Octane, etc. and the literature implied that some octane boosters contain things that can ruin an oxygen sensor.

I have no idea if that is correct.

I never put it in my new cars again, I am just using up what I have in some old carburated engines.

John

 

I have the same pinging problem being described on here. I've actually put off going in to the dealer with it as I'm almost positive they'll try and blame my mods and I just don't want to deal with that (again). But I am wondering...does the pinging send a code reporting the problem and should therefore be detected by the dealer when you take the car to them?

Also, petecrosby wrote,"A malfunctioning EGR can also cause ping and severe hesitation". I have that severe hesitation in addition to my pinging so what is a EGR?

Thanks,
Ken

 

Never mind, did a search on here. EGR = Exhaust Gas Recirculation valve. So they'll blame my exhaust and header for that.

Paranoid? Me? Well yeah.

Ken

 

What octane gas do you have in your area? If you are limited to 91 octane, you are already starting out at something of a disadvantage. If the oxygen sensors and plugs are replaced and the pinging is still there, you are going to have to consider increasing the octane of the gas you put in the car. I personally would not go with octane boosters. Even if there is nothing in the booster that damages emission system components, the price of the booster does not justify the expense for the increase in octane rating. A booster that claims to raise the octane rating by 4 points only raises the octane by .4 (e.g. 91 octane gas before 4 point booster is added is at 91.4 octane after addition of the 4 point booster). If you are trying to get from 91 octane to 93 octane, you would have to add 6+ cans of a 4 point octane booster to the gas. Do the math and you can see why I am underwhelmed with boosters.

A better approach to raising octane is by adding 100 octane unleaded racing gas. With the MINI's gas tank, I believe that 3 gallons of 100 octane unleaded racing gas with the balance of a fill-up being 91 octane gets you to 93 - 94 octane for the tank. As to where you can get 100 octane unleaded racing gas, there are Union 76 stations that carry the stuff, so if there are Union 76 stations near you, that would be my first choice.

If you can't find gas stations that sell unleaded racing gas, then you are looking at doing your own blending with toluene or xylene that you buy from a paint store. Personally, I would try to find a source for the 100 octane racing gas. If you use the racing gas that is sold by a retailer and there is anything wrong with the gas, the retailer or refiner has an insurance poilicy that will cover the cost of repairs to your car. If you use an octane booster or blend with toluene or xylene, you are on the hook for any problems that may occur.

 

Man! I'm glad to see that I'm not the only one with an 05 MCS that pings on California gas.

 

All I know is that the bottle says safe for sensors and emissions systems and I no longer have pinging in 100+ temps. If higher octaine gas was available I would buy it, but I'm sure it would still cost more than the $2.50-5.00 per tank that boosters cost anyway.

 

I am runnning 91 Octane. Thought about adding some racing fuel to get closer to 93. However, the fact is none of us should have to add anything to the fuel unless the car is highly modified. My understanding from searching this site and several others is that the ECU should be able to adjust the timing and a/f ratio so that no pinging occurs even when using 89 octane. The engineers at BMW/Mini had to know a lot of these cars would be running in states where the highest octane available was 91. Ok I am ranting here but it seems ridiculous to have to add racing fuel to a basically stock car just to get it to not ping..... If that is what I have to do, Mini can have the car back!

Adam

 

I'm with you, BMW, and everyone else, has cars that do not knock with CA gasoline. Knocking is not good for the car in the long run and there is no way that we should have to mess with the fuel or anything else to have the car not knock/ping and behave correctly.

 

Running 93 in my 2005 MCS - no knocking - smooth HP and torque curves on dyno

 

Here in Illinois, I typically run 93 or 92, but once in a while when I'm feeling ornery towards the gas company for their prices I'll buy 89 (silver, or mid-grade). I've never had any issues with pinging or knocking. This was true for my '02 MCS as well as my new '05 MCSa.

I'm with the opinion on a bad sensor.

 

You don't need to worry about your mods upsetting the EGR on a MINI, because it does not have one.

I live in Northern Illinois. Yes you can get 100 octane unleaded gasoline. I have not priced it this year. Last year I ran out at the track and had to buy a couple of gallons, at $5.75 per gallon!

According to the engineering paper on the MINI, its knock sensors allow it to safely run ANY gasoline available world wide. If you are really hearing knock, there is a problem.

John

 

I have just noticed pinging in my 04 MCS this past weekend. Happens underload, heavy exceleration at Lo RPMs, with A/C on. It is 110 here in AZ, but on runs over the weekend with may other Minis, no one else seemed to have issue. I have used nothing but Chevron 91 since day one. Put techron injection cleaner in 1/2 way through weekend, now 4 day later and almost a whole tank, still pinging.

 

Why do you think that injector cleaner will stop the pinging?

 

You can run any gas safely with the mini. You just can't run low octaine up hill, full throttle, in 100 degree heat in fith gear.

There is a big difference between knock and ping. I doubt anyone is hearing knocking.

PS, My posts are not meant to be negative, oh forget it, my car runs fine and you can lead a horse to water, but...

 

trouble shooting... 1st step... maybe got the bottom of the gas stations barrel...