I have a 2003 Mini base model. I was sitting at a stop light when my Mini started running rough. I drove back home it runs rough at idle and while driving. The gas cap is new and tight. I changed out plugs and wires. I am unsure how to proceed. I am guessing coil pack? It states that cylinder 4 has a misfire. I noticed a tear in the intake hose coming from air filter to throttle body. No one has a replacement air intake hose where I live so I patched it with a sleeve and duct tape. No change in running rough. I will get a new one ordered but am sure this is air tight used a cigarette to see if it pulled in air. Will a bad coil pack throw P0456 "small EVAP leak" code? I have looked all over and it said could be a vacuum line due to running rough throughout the power band of the engine. I have to drive 30 miles to get any parts and have no other vehicle. Will I damage my Mini by driving it the 30 miles? I appreciate any assistance in this matter. Very frustrated with it.

 

Thinking that P0304 is a cylinder misfire, #4.

How many miles on the car? Do you use premium gas? The Tritec is a good engine but I have heard of issues with premature valve guide wear that leads to a burnt valve by not using premium. Do you know what a Dollar Bill Test is? I have a thread noted below, there is video on the dollar bill test within it.

https://www.northamericanmotoring.co...loss-help.html

 

139K and use 91-93 octane. Will look at dollar bill test. I appreciate your help.

 

If it sounds like a tractor, most likely a valve but could also be a bad gasket or a cracked head.

Good luck and we will keep our fingers crossed.

 

*****, bad timing for that. Spending a fortune in court battling a drunk ex-wife.

 

If a valve or head gasket would I not see other symptoms? It doesn't over heat or smoke. No coolant in oil or vice versa. Would it also happen just sitting at a light not under stress?

 

When I had an exhaust valve burn out, the only code that I got was, I believe, P0303. Misfire, cyl 3. Changed plugs, wires, and coil pack (OEM), and still would get the same code. Had all 8 exhaust valves replaced, and the head decked.

 

How much did that cost you? I am still just floored I was at a stop light and this happened.

 

There is basically the same amount of energy released per detonation cycle at idle as there is at high rpm. As the valve guide wears more and more hot gas is leaking around the valve, the gap gets bigger and bigger to the point that there is no seal left. For you it appears that happened at a stop light.

There is recent thread on valve job costs, I am thinking if you can do the mechanic work of taking the engine apart and putting it back together you are looking around $1k, a shop will be around double that.

 

I appreciate the info. If this is the issue I may just look into a new car. Ugh!

 

I got lucky and it was the coil pack. Had to end up purchasing it from Mini for $162. I spent around $220 total between plugs, plug wires, and coil pack. They gave me a discount for being a fire/medic. I am grateful for that!

 

 

Detroit Tuned (great people) did all of the head work + new thermostat, timing chain/guides/tensioner, front main seal, gaskets/seals, oil change, etc, for about $2300. Car runs great now.

Glad that it was just your coil pack, and it was great that MINI gave you a discount for your service.