My Mini: 2004 MCS - 90k - No "mods" to speak of.

My mini has been doing fine until 2 days ago. I was changing lanes under mild acceleration and she just started shuddering really bad and the check engine light started flashing. I took it out of gear to coast into a parking lot to check it out and she died as soon as she tried to idle. I was able to get to lunch and back home (~10mi) as long as I kept my foot on the gas to help her idle.

I changed the spark plugs soon as I got her home, no help. I pulled each plug wire one at a time to see if it made much of a difference and they were all equally rough so I assumed it wasn't one bad cyl. A later trip to Advanced Auto where a friend checked the codes assured me with a "Random misfire" code.

We guessed water in the gas? or something like that since I put gas in 10-15miles before it started acting up, so I added some premium that I was sure was clean and a double dose of injector cleaner and drove another 5 miles to work it through the lines.

She idles now most of the time, but still sounds like a carnival go-cart definitely still skipping, I'm sure its somewhere in the fuel system or timing maybe? But I'm really not too sure what else to check. And I really don't want to leave her with a mechanic.

Any advice?

Thanks,
Nick

 

-Bump-

Anybody have anything?

 

1. You should always run Premium fuel

2. the injector cleaner you put it, won't help it usually only makes it worse, the chance that you have water in the gas is very small and rarely happens.

3. Spark plug wires? you have 90k they are due

4. Coil pack?

I'd do 3 and 4 unless you have other codes, but they are maint items anyway.

 

This could be MANY different things. Very difficult to diagnose a random misfire if its nothing obvious like plugs, wires, coil, wiring etc...

 

Great first step....and to expand upon it
1)your car REQUIRES Premium fuel....not using it can cause MAJOR damage...some folks get away with not using it...but when you get a $3000 bill to fix a motor, the $3 you saved filling up will seem like a waste!
2)Injector cleaner will lower octane....it is a solvent...so it may make it worse!! If the misfire is due to low octane...you just counteracted the good fuel you used.... Since the misfire is random, it is not due to a single clogged injector....and water is a non-issue these days due to the fact most gas has plenty of ethanol (10%) in it...so it will remove the water unless you have a ton!!
3)plug-wires...like he said are due....they often get a bit of corrosion, and as they age, the resistance goes up....
4)Coil-pack....could be going bad...it is an electrical competent.

One more thing I might add...have you changed the spark-plugs? They are likely worn, and when you re-install them, USE a TORQUE WRENCH!! They are often BLOWN OUT of the MINI head is not installed to the right setting, resulting in $$$ for repairs.

If these 4 items that are easy DIY don't fix it, it is time to get some help from a pro to dig deeper. Just hope that no Dammage was caused by using gas with octane that was lower than was required. Damage that may occur includes, but are not limited to Piston and piston ring damage, head cracks, valve damage....all kinda $$ to fix.

 

I was getting a random misfire code about 2 months ago on my '05 MCc....I'm no longer getting the code after I had some work done. New spark plugs, I only got premium before but now I only go to shell (at bmws recommendation) as opposed to sams club (I'd been going there for the last year), I ran some chevron tech through the tank, and did a 1/3 or so bottle of sea foam through the pcv.

 

My Cooper S ran like crap on Costco gas even using the premium grade. I couldn't figure it out but it just wasn't performing well. It was so bad that I was getting passed by more gutless cars.
I switched to Shell premium fuel and it's got its liveliness back.

 

After not having time to work on her for a couple weeks I took her to the only BMW mech in this town.

I had replaced the plugs and wires and he checked the coil pack by swapping for a new one. It wasnt the coil pack so the old one went back on and there was no charge (Nice mechanic).

He checked the codes and got 5 or 6 differnet ones, the Random missfire one I sopke of earlier and a couple on the throttle body and some other strange stuff, Ill post those when I get a copy from him tomorrow. He then did a compression test per my fathers suggestion and came up with some not so good looking results.

Cyl 1: 0psi
Cyl 2: 150psi
Cyl 3: normal
Cyl 4: normal (I honestly dont know whats normal)

I know that absolute 0psi is a really bad thing cause if the engine is cranking, the pistons movement from the crankshaft alone should cause some psi change right? Maybe the piston has a hole? or is broken?

Im getting it back tomorrow because he wants $120something in labor to "remove the intercooler and valve cover to see if the valves look out of place", Im pretty sure I can handle that in an hr or so.

I dont have my baby paid off yet so Im really hoping this isnt catostrophic but I am expecting to pay out a little in the near future

Any ideas or suggestions? I know Im going to have to find an bently or haynes manuel so I can learn about what Im taking apart. Anyone know of some resources to get me started looking at the valves and pistons? I could use a little help making sure I know what right should look like when I start pulling things apart.

And thanks for the tips on Gas. I never put regular in, its always premium or that and silver mixed, since ours is 87, 89, and 93 octane here in GA and the Mini calls for 91, I figure a mix of 94 and 89 will be fine right?

 

This is a direct link to a good camshaft guide.

http://www.werkinmini.com/R50-R53%20...stallation.pdf

It is the first hit here if you can't DL directly.

http://www.google.com/search?q=r50+r...t+installation

I have it as a pdf and don't think I can post it here.

It isn't a bad job really, good luck

There are a bunch of steps you don't need in the guide to just get the cover off, so choose wisely. Really once the intercooler is off, you might just want to wing it and move what is in the way. I figured the pictures would get your mind in gear for it.

 

Thanks!

Allthough I have little experience with the inside of an engine I do have a mechanicly oriented mind and love to take things apart. This looks like the type of learning materiels I need!

Im thinkin maybe since I have to tear it down this far should I go ahead and put a SC Pully reducer on and give this storm cloud a sliver lining?

 

I'd call Waymotorworks....maybe even have the car flat-bedded to Atlanta if you are a reasonable distance away....it is likely that a "new or different motor will be needed, or if you are lucky, just the head. Either way, he sometimes has some cars he is parting out, and may have a good used motor or head...and he know the Gen1 MINI's better than the dealer guys...he is factory trained, and left the dealer to open his own shop.
It sounds like you are driving it still?!

You might be doing more damage, hurting OTHER components...like the Catalytic converter....stressing the crankshaft and bearings with the misses...It is hard on the motor in many ways...
It sucks to have a problem.....

 

I had a voodoo random miss fire a while back. after replacing plugs, wires and coil pack it still would occur mainly at low idle. it ended up being a short in the wire loom going to the coil pack. trace the wire back to the first hold down clamp that secures the loom to one of the valve cover bolts, left rear corner of the valve cover. don't know if it is possible that you have the samr thing but it sure kicked my but till I found it.

 

Well, if the engine is missing zippy is correct, you would be dumping completely unburnt fuel into the CAT, not a good thing.

 

Big update.

I took the head off to replace the gasket and check the cylinder walls for scaring and found a chunk missing from a lobe of the Cam. It was the exhaust lobe of Cyl 1, the one that was "0psi".

No other issues if any kind, everything else looked perfect, cept for the #1 injector was a little black and the roller of the 1# exhaust rocker arm.

So would a chunk off the "flat edge" of the exhaust lobe cause 0psi?

I didnt think so myself, but I could see where it would mess up the the whole combustion process.

So I replaced the head gasket, cleaned everything, got a new camshaft (ns1 from outmotoring) and I have a new rocker arm on the way.

Today I put it all back together cept for the new rocker arm, I figured the old on would be fine for now. And started and fired it up.

All the noises scared the crap out of me at first. But, I didn't realize the intercooler HAD to be on, that eliminated some noise, and there was a lot of smoke but that Im sure was just the little bit of oil I put in the Cyl's to keep them from corroding after being cleaned with carb cleaner (long story).

So Im still left with a clattering noise coming from the valve cover.

After some reading I see where one guy had his rocker arm rail on upside down and it was keeping the oil pressure from building up and not getting to the lifters. I'm 99% sure they are right, but Ill double check tomorrow.

A second idea I got from reading is the timing chain tensioner. I did depress the piston behind the plastic rail piece on the exhaust side so I could get the sprocket on the cam. and maybe it hasnt popped back? It sounded like I could press on it again and it would pop out?

Thanks for all your help guys, my poor Mini and I have been separated for almost 2 mths now while Ive been going to college and working to pay for the parts. I really need my Mini back!

Sorry if that didnt make a lot of sense, its been a loooooong day.

 

I checked the rails and they are correct. Ive looked over the whole head 10 times already and everything is in the right place.

I have not ran it for more than 15 seconds because I don't want to hurt anything since I don't know what that noise is. A local mechanic said that 15 sec is not enough time for the oil pressure to build up and reset the timing chain tensioner and that I just need to run it longer and it will be alright.

Good idea or not?