Hi all. I know I’m far from the first to post this issue. Just reviewed some older threads and would like the chance to describe my experience for any additional info someone may offer. This is an 04 MCS 6 speed. I have p0302 for cylinder 2 misfire, along with p0456 for EVAP system leak. What I have done so far: - corrected leaking valve cover gasket. Oil was leaking from the back right corner, that is now resolved with new gasket. - that leak allowed oil onto cylinder 2 spark plug. That plug is replaced with new. The other three are clean. All four were installed new in May 2020. - replaced the gas cap. Codes return immediately after with Creator C310. My quick fixes haven’t improved anything. This weekend the SES began blinking and added the ASC light to its attempt to get my attention. That came with more pronounced rough idle, bogging down and loss of power, only to suddenly revert to perfectly normal operation with smooth, quiet power again. It will switch between bad and nice a few times on any drive. It will also sometimes stall shortly after cold starts. Always starts back up immediately though. I’m really trying to avoid having my shop look at this as it seems like an expensive wild goose chase to narrow these problems down. I know that these issues are notoriously hard to identify. I don’t have the tools or knowledge to do a compression test or a smoke test... I’m willing to change that though if that’s the smartest next step. I’m considering new plug wires and ignition coil as well. Really not too expensive to replace them, but I would be annoyed with myself if I kept up on the path of adding new parts only to have the problem persist. What are the other usual causes of these issues? Should I be looking at fuel tank leaks? Vacuum leaks? If so, from where? I have new Alta silicone intercooler boots, they appear to be seated properly but that seems like an easy spot to lose air... any other ideas to help me diagnose? Thank you! Sent from my iPhone using Tapatalk
Get rid of the Alta IC boots they are know to leak. Go back to stock. I had to do the same on my R53. Check the contacts on the coil pack they do get corrosion on them. If you replace the coil pack use the stock one. It is good to 300hp. People have had trouble with aftermarket ones. If the fuel filter has not been changed I would replace the filter, it may have been the cause of the ruff ideal and bogging down. Even if it doesn’t fix it if that’s the original filter it needs changing. What plugs are you using? Do you have a different supercharger pulley?
I’m on the right track, this is great to see your response. I put the original IC boots back on today and it ran smoothly right away. ASC light is gone, SES still on but I was in a time crunch and didn’t hook up the reader to clear it and see. Will do that tonight. I put in four new NGK double platinum plugs last May, and replaced cylinder 2’s plug with an identical new NGK last night. And like I said in the original post, I believe I’ve eliminated the oil leak that I had, there’s no fresh oil in that plug well since replacing the valve cover gasket ten days ago. And luckily there was no sign of coolant in any of the plug holes to begin with (so I’m ruling out head gasket I hope?) Good advice on fuel filter. It is original. Forgot to state mileage... 149,000. As you say, definitely seems a safe bet to replace the fuel filter whether it’s causing any of this or not. I’m really optimistic about this all being down to the dumb Alta boots. My next step will be to get eyes on every vacuum line and connector, but that requires front end service mode all over again to really see everything (unless maybe a borescope could get under enough stuff to let me see the hidden lines). Stock and original supercharger pulley. I had the supercharger out last spring, replaced its oil and green gasket, and replaced the serpentine belt. No issues since then until this leak and misfire started. Errors were greatly intermittent at first with no change in drivability - first error appeared four months ago which when I type it looks ridiculous, like I willfully ignored this... just didn’t know where to start until I had worse symptoms, and the possibly related oil leak from the valve cover kicked it all into gear. And now the misfire and vacuum leak is noticeable problem. Sent from my iPhone using Tapatalk
A few things to add to your list. When you did the belt if you did not replace the tensioner pulley and idler pulley at that mileage it is a must. Make sure and take a good look at the rubber on the crank pulley if it is getting cracks in it I would replace it. You don’t want it to fail. If you have not had the lower a-arm bushings replaced I don’t have to see the car to know they are bad. They go bad around 35k. I would replace them with PowerFlex bushings they will last the life of the car. I am glad it sounds like the boots helped. Nothing better than an R53. How long have you had the car?
Yes welcome to M/A. I had an R53 but have forgotten most of what I knew. I'd put an ATI crank damper on there. Since you need one anyway at your mileage you might as well upgrade. Also if you haven't done so yet put a new set of spark plug wires on. You don't need anything fancy stock ones or NGK wires will do.
Thanks for the attention you’re giving this, really appreciate it. Believe it or not, I’m the original owner of this R53. Ordered it to spec and picked it up about six weeks later on Memorial Day weekend of 2004. Two years ago I was prepared to part with it as I decided to go one year older and bought an 03 BMW 540. But my son, who was just turning 16, surprised me by wanting to learn to drive a manual before I sold it. Of course we did that, he proved to be a natural, and there was no parting with it at that point. He was 2 when we bought it and it’s his car now. Pretty cool outcome. So now we’re learning some mechanical basics (and a bit beyond basic) and having a good time working on it to keep it in good shape for as long as we can. I think I replaced those damn bushings (at a shop) almost exactly every 35,000 miles lol... and finally wised up and had Poweflexes put in the last time. Thankfully I don’t even remember now when that was but they’re good to go. Just had my preferred mechanic put new front axles on. I didn’t feel like we had the time to learn that right now. The misfire and EVAP leak codes have been going on but the shop was so busy we just took the car back to troubleshoot on our own rather than leaving it there for another few days/weeks and hundreds of dollars at least while they hunted this down. I guess I’m kicking myself now because I did not replace the pulley when everything was off for the supercharger service. It looked visually good and normal, like new really, but I didn’t have its age on my radar as a need to replace. Not like I’ll never pull the bumper off again so I can put that on the list. Ok if you’re still with me, here’s the latest on my original post. Lot of good news - it’s running so well. My son drove it a few times with no rough idling and so have I. I cleared the codes and for the first time in this saga they both actually cleared - for a bit. The SES and ASC lights went off after clearing codes, but the ASC light came back on. Checked codes, and the cylinder 2 misfire code is back. No SES and no code for EVAP leak so that’s half the battle down maybe. Now I need to figure out the misfire. Worried about bigger problems either causing it or to be caused by it - like a bad cat maybe? I replaced both oxygen sensors a year ago due to rich running codes and that solved the codes. Then we had a cracked exhaust manifold that we had replaced. Like I mentioned earlier today, I have a brand new plug in cylinder 2 and the others are about 8 months old and visually in good shape after pulling them to inspect last night. Now I’m thinking I may as well replace the wiring harness and probably the coil pack. Of that clears it up, great, if not they’re original and may as well be replaced (cars has 152,000 not 149,000 like I said before. I’m losing miles same as I’m losing track of time it seems). I have never done a compression test but seems easy to do, can get a tester kit at harbor freight for 50 bucks, seems worth it what with the big old BMW V8 wanting my attention too. That would at least tell me if I should be planning for much bigger issues (piston rings or damaged cylinder or even head gasket even though we don’t have those symptoms really). Sent from my iPhone using Tapatalk
Seems like plug wires are the smart thing to do next. I’ll check out the ATI crank damper too, thanks. Sent from my iPhone using Tapatalk
The crank damper usually goes sometime just over 60,000 miles, so if it is original I would bet it needs replaced. Like Chuck and Lee said, stock plug wires and stock coil. Good luck! You’ve got the best generation MINI. Sent from my iPhone using Tapatalk
The ASC light is for your traction control. When I had a bad wheel speed sensor on mine it threw that light.
Could easily be that, seems odd though. I replaced both front abs sensors maybe three years ago, not that they can’t go bad but that the ASC light has been on due to the evap code (I thought). At any rate, both of our codes are back after one day of clean living. Misfire and EVAP leak. Car is running well though but I figure that’s temporary too. Clearly those intercooler boots must have been a major source of a vacuum leak, and now that it’s well sealed there, the leak is just getting through the next weakest link. The misfire code came back first and the evap leak was a few hours later in the next startup yesterday. They’re both present at startup today. Next order of business is new plug wires and ignition coil, was going to do that anyway. Hoping to solve the misfire with that but then I’ll have the vacuum leak to track down still. Sent from my iPhone using Tapatalk
Yeah did that first a few months ago. Similar to the inter cooler boots, it resolved for a short period of time. Maybe a week, then code was back. Ran okay today, both codes present. Yesterday it bogged down once in low revs after cold start. My son was driving, he shut the car off, started up again and it was okay after that. Plug wires and ignition coil shipped today. I also replaced the purge solenoid valve (correct name?) the little canister right in front of the engine on the passenger side that takes one minute to swap out. I’d hoped it was the culprit but that changed nothing. I’m definitely in “throw parts at it” mode which I don’t love, but on the other hand I am replacing parts that have 150,000 miles on them. You mentioned fuel filter in one of your replies. Thinking that I should consider that as well. But really, I think I have to bite the bullet and set aside the time to pull the bumper and slide the radiator out so I can get eyes on all the vacuum lines. I’m worried about those two rigid ones that go to those red ring connectors, right above the thermostat. I had a hard time getting to reconnect when I was in there. Concerned that maybe I never did all the way. Sent from my iPhone using Tapatalk
I am really not sure if the fuel filter will solve your problem. I changed the one on my R53 at about 120 miles just because I thought it was a good idea. You would not believe how black that thing was! And I am picky about where I buy fuel. Side note, you may know this being an long time Mini owner. When BMW/Mini says something is lifetime, they mean the average length the first owner will have the car. You my friend are way past that. As @00Mini said replacing parts at the age of your car is not bad.
Yep, preaching to the choir on BMW’s “lifetime” line of bull lol... I’ve been sorting some of those things out on the mini and my bmw over the past year. Plug wires and ignition coils just arrived from FCP so I’ll get those in this weekend. Fingers crossed it solves the misfire, then I can narrow down to the vacuum leak. Who knows. Sent from my iPhone using Tapatalk
If the new coil and wires does not solve the problem, do a compression test. Low compression in that cylinder will cause a misfire and that in turn will cause the DSC light to come on.
Was heading here for an update this morning... New plug wires and coil didn’t make any difference. Thanks for the compression test advice, that seems like the logical thing to do (probably could have done that first). The car is leaking oil pretty badly now as well, haven’t been able to find an obvious source of it yet. Based on running my fingers around the valve cover edges, it’s not the new gasket. The weather was terrible this weekend and I couldn’t really get as deep into it as I wanted. The engine is making a new clicking sound from the passenger side. I took a video and will upload later on. To my ear it sounds like it could be from the belt/pulley area. Pulley was mentioned here last week as something else to look at. Once I get the video shared I’m interested to know if the sound is familiar to anyone. The car is really trying to revolt on us now! Sent from my iPhone using Tapatalk