Once again I am having issues with our 2002 MCS. This time around the symptoms are rough idle that wont go away along with severe pinging. Last time it did the rough idle I replaced the plugs, coil and wires which healed it for a about 9 months. This time I have replaced the coil and plugs, swapped out the wires and it did not help one bit. When driving the engine pings badly under any load at all, in fact I can here the ping at idle when I am under the hood.

What else could cause these issues?

 

just a thought, the sound you hear under the hood may be the sound of the injectors firing, which may be normal. The ECU acting on the advice of the knock sensor should retard the timing to eliminate pinging as soon as it is detected. Pinging is caused by low octane fuel, higher that normal compression (carbon buildup), bad engine timing or lean fuel mixture.

Do you have a SES light or any pending codes stored?

 

Try putting a bottle of techron or sea foam in the gas tank and run it for a while.

 

Also try an Itlalian tune up. (After the engine is warm, floor it to redline in first and second a few times.)

 

We've put about 30,000 miles on our Mini so I know the sound is not normal. I have already put a bottle of Amsoil gas treatment in which is usually a cure all for stuff like this.

The issue I had before this one was the wiring to the front o2 sensor got against the exhaust, shorted and blew a fuse. This was also the knock sensor circuit. If the knock sensor got damaged or is malfunctioning will it cause the car to run like mine is?

 

There are certain conditions that will cause the ECM to go into a limited strategy mode,including running fixed timing!

If any of the sensors are open, shorted to 12v or ground, or operate outside of a certain range the plausibility monitors will fail and an error code will set; in the case of problems with wires the code will set without driving the vehicle.

Do you have an SES light?

 

It is very likely a fault code has been generated with those types of symptoms. Have some diagnostics performed to provide a clearer idea of what area should be addressed. In the absence of a fault code (and since the plug wires are new), a rough idle could be caused by a leak at the supercharger intake duct and supercharger. The green gasket can loose its seal, especially after oil has begun to seep by. Drive the front up on ramps, pull the splash shield, and look where the supercharger intake duct meets the supercharger, if it is very wet and dirty this would be one of the things to address in the troubleshooting process.

A fuel additive won’t guarantee the fuel injectors are healthy, if you can do without the vehicle for a few days, have the injectors reconditioned.

 

The SES light is not on. However I did a code scan on the car and had an advanced DTC code P1692

 

I had my 2002 MCS at the dealer some time back and they did an update on the ECU as part of normal maintenance. It turns out that my car will not run on any other version of the software that that which came with the car.

The dealer was ready to tear the engine apart when I asked them if an ECU update was performed. It took a few days for the roving specialist to show up with the original code. Unfortunately, all he had was European and not American programming and that made things even worse! Finally, after about a week, they got the original software, reflashed the ECU and all was well.

I suggested that my SA add a notation to my file regarding the updates, which she said she would do.

 

Anyone heard of the P1692 code??

 

This one can be a little tricky to diagnose so I consulted with a very knowledge gentleman from another forum. Follow this link to see his reply.
http://tech.bentleypublishers.com/th...threadID=38285

 

Thank you VERY MUCH! We have not driven the car in about 2 weeks because of the issue its having.

 

Any new information about your problem?

 

Believe it or not the car has been parked all winter long, I have not driven it since November 2008. Just last night I pulled it back into the garage to figure this problem out. A local shop diagnosed it with a blown head gasket (it was there for a code scan, which they didn't even do). Before I go to the aggervation of a head gasket I want to make sure that's the problem. Here is where I am at now:

Cylinder 1 90 psi
Cylinder 2 90 psi
Cylinder 3 150 psi
Cylinder 4 150 psi

Yes that does point to a head gasket but it could be the valve adjustment to I was told.

All cylinders are firing and getting fuel. The spark from the plugs is orange though, not the typical white or blue. I was told that indicates a weak charge, like faulty plugs, wires or coil (all of which are new).

I just read the service bulletin someone posted on another forum and will be checking it out:

http://tech.bentleypublishers.com/th...threadID=38285

 

I bit the bullet last night and started pulling the engine apart. I had a second shop (Mini of Sterling, VA) tell me it was the head gasket. I will post the results when I'm done.

 

I found the problem. It is a slightly blown head gasket...

 

Well, if you were inclined to do any more mods, you're right there now.

 

I finally got this car back on the road after setting for over a year.

I installed a new head gasket after taking the above pics. After starting the car there was no improvement in the idle. Checking the compression in the #1 hole revealed it was still only 60-90 psi. I was disgusted to say the least and let the car set several more months. Then I decided it was time to tackle it again. I stuck an air hose in the #1 cylinder plug hole with 120 psi. while I rotated the engine by hand and discovered the only place I could detect the sound of air leaking was coming up through the timing chain area (lower end). I figured the rings might have gotten "washed out" by unburnt fuel. I pulled the oil pan off and removed the #1 rod & piston. Found that it had detonated (burnt the rings). This was most surely caused by my wife running 87 octane fuel in it & several overheating episodes didn't help. Luckily the cylinder wall wasn't hurt. I found a used piston on NAM, bought new rings, gaskets and put it all back together. The car is finally on the road again.

 

All of these problems, are major stuff.
You did well in diagnosis, you certainly has b@lls opening/working on the engine.
More power to you. I give a lot of credits.

 

Congrats on the fix--you had plenty of work to get that car back on the road. I looked at your sig and there's no mention of a tune on the car, which, in combination with the low octane fuel that your wife was using, could have accelerated your motor's demise. If you bought the car used, be sure that there isn't a more aggressive tuning file in your DME, or put big signs on the fuel cap to always use high-octane fuel. I have a customer who bought a used MINI with a tuning file which he wasn't aware of, was cheap with gas, and earned a very expensive fix for his efforts. You don't want to re-do your work .

 

I hope you don't continue to have poor ring sealing or develop scuffing later; used pistons are often deformed. You may have measured the cylinder bore and pistons to determine it was ok, but for others caution is advised.

 

It's amazing you can replace a piston without having to pull the engine! Or did I miss that part?

Edit: on second thought, I guess it's not that hard to do in situ once you've removed the head and the oil pan!

 

Yea with the pan and head off its easy. I was a little nervous about disturbing the connecting rod bearing but it went well.

Funny thing is for this car you can buy the rings per piston, but you cant buy just one piston. A set of 4 pistons from Mini is around $1,000 which makes the $125 I paid for a single used one sound cheap.

 

Yet another cautionany tale on why NOT to run out of spec gas in a MINI. Good to hear that all is well again!! Congrats!

 

Maybe they want you to replace all or none (weight matched sets?). Or maybe it's just for revenue enhancement...