So I was pushing the ol mini pretty hard late at night, going 100+ for a solid minute. After a bit I noticed that my throttle response was cutting out, I was in 6th and foot was on the pedal and I noticed RPM drop. I figured I let off a bit so I pressed down again, it rose but then it dropped. Then, I noticed white smoke coming from my exhaust and my engine light started flashing. I put it in neutral to coast to a stop. The engine didn't die but I didn't trust it to put it in gear and risk damaging it. I hopped out, checked the engine and it didn't appear to be leaking any fluids. I was worried about a blown turbo or headgasket but everything seemed in order. There were no lines disconnected, coolant lines were intact. I checked the oil and there were no sparkles thank God. Gave the fuses a run down and none of them seem blown. I started it again and it started, but it was stuttering hard. Didn't seem like the engine was receiving enough fuel to keep it going. This happened last night and I didn't have time to look for codes or any of that good stuff. But I would like some help figuring out what the issue could be and what are things to look for? My guess is a fuel pump, but I'm unsure. Any help to get my Mouse back on the road would be greatly appreciated.

 

Looking at your previous posts reveals that you have once asked about a dashcam for a 2012 MCS. Does this thread relate to that car?
What mileage?
Any modifications?
Any previous repairs?
Any other information that may be relevant (e.g. bought at which mileage, previous owners, etc.)?

Help people help you.

PS.: Running a Mini at 100+ for a solid minute has in itself no negative effect. Besides, hard acceleration is more detrimental than e.g. constant speed. I've driven my base Cooper at 100+ over hours, going for several minutes at its top speed of 125.

 

Hey, I don't know if this is related but about two years ago I had the service belt replaced. Some month later I took the car before going on a long trip and wanted to check everything was in order before the long drive. I hop on the highway and getting on the ramp I punched it to get to speed. Next thing you know the engine reacted badly. And the car is now on limp mode, CEL on with a rough cylinder shakes. No power. Just enough to move forward. I get off the highway safely and parked as soon as I could on a lot. Turned off the car. Open the hood and do not see a thing. I wait a few minutes then start the car again. Everything seems okay. Of course after that scare I'm babying the car but nothing abnormal to notice. Long story short we took off on our trip and broke down 2/3 of our way. We're like thousands of miles away from home with all sorts of weird electric problems. We have the car towed and some parts replaced and think we're home free. Later on we drive back home and as we are an hour away from home we get some weird engine things again. I drive calmly and that week get the car looked at again.
It turns out the belt was off by one tooth. Most likely from the prior belt service. My guess is that the belt was not tensioned properly and when I punched it the tooth slipped. Why the electric problems after that I'm not too sure of the strange coincidence. Maybe some high power spikes from the initial miss fire situation. No way to complain about the service belt without much proof...

All this to say: It might not be a bad idea to check the service belt.

 

Hi netj0x,

I have had that same issue what you just described and my engine light started flashing. I hate to to tell you this but you have lost a compression in one of the cylinders due to a chip on the valves causing to lose compression. Sorry to hear that bud but you need to get the head off and replace that valve. Mine was an exhaust valve in CYL #3

 

Yeah sometimes i post and just forget to check the website. This is the same car. I bought it at 59000 miles and it now has 67000, from last to this year. It has a CAI, full catback exhaust, catless dp, burger tuning chip. It has never had any other major repairs, and without the carfax I couldn't say for sure what the maintenance on it looks like but from what I saw it was maintained well. With 1 previous owner at $12,000 I figured it was a good bet. Right now it's throwing codes for cylinder 3 and 4 misfiring, with codes P0303, P0304, and P0300. We tried swapping the coils and it still misfires on the same cylinders so that eliminates that. Cleaned the spark plugs and they were in pretty rough shape so next step is to replace those. Didnt try it after cleaning the plugs because the way it sounds makes my heart drop. Start up is very rough but when it idles for a bit it doesn't stutter as bad. I've heard things from headgasket indicated from the white smoke to a chipped valve as someone mentioned in this post. I'm gonna do a compression test, I'm not mechanically inclined but YouTube helps. At this point it's eliminating possible issues and narrowing it down to the potential culprit.

 

I will definitely give that belt a look, seeing all the other possible issues, expensive ones at that, I will definitely make that top of my list. For me, starting it is very rough, and it throws P0303 and P0404 codes. I havent driven it for fear of damaging the internals to in irreparable state, but it does idle fine after sitting for a little. After checking the fuses, swapping coils, checking coolant lines and all that good stuff, it seems to me to be a fuel or air issue. Nevertheless the belt will be checked, and hopefully if it isn't that the real issue is just as simple and inexpensive.

 

Oh boy that does not sound like a good time. Did you check the compression or have a shop do it? There aren't any mini dealers within 2 hours of me and bmw is the next viable option. Is it worth it to take it to shop to diagnose the issue or should I do a self compression test? Being that it gives P0303 and P0304 codes would it be possible that injectors are toasted or possibly the headgasket is cracked? I'm pretty tight on money and am weary of dealerships doing unnecessary work on my car. I've heard things from headgasket to valves to the spark plugs, but honestly I'm not sure how to go about diagnosing all those issues without breaking the bank.

 

Do you have a BMW/Mini specific scanner? If not, sound like you should get one. Make it much easier to diagnose.

Coil(s)?
Plug(s)?

 

Hi netj0x.

Any repair shop can do a compression check since it is a simple tool that screws into a spark plug hole and besides it is NOT expensive at all to do a compression check. Before you go any further trying to find out what is causing the roughness, a simple compression test will eliminate hours of searching for the cause. Of course if all cylinders do have compressions, then you're in luck but hours of searching. If the head gasket was cracked, then you'll be having white smoke coming out of the exhaust and oil spewing all over the engine block or oil mixed in with coolant.
Check this photo out when I found out that I had no compression cylinder #3. I was so dreading and my heart stopped when I heard that I had no compression. It meant that I had to take the head off, timing chain and the entire front bumper off including the radiator and condenser

 

@TG. :
What car/engine are you referring to? AFAIK, all modern (i.e. by BMW) Mini's come with a timing chain, not a timing belt (at least the petrol engines, don't know about the diesels). The only belt in @netj0x 's car is the auxiliary, serpentine belt which would have absolutely no impact on his issue.

 

@giorgos

I think @TG. may have mistaken timing belt for a timing chain. I have not heard that minis have timing belts.

 

We used my friends bluetooth scanner which is newt but doesnt provide the accuracy as you stated. I will most certainly look into that. I'm not sure wym by "Coil(s)? Plugs(s)? but I have oem ignition coils and spark plugs that were never changed I believe. And I ended swapping ignition coils to different spark plugs to see if the coils were the issue causing the misfire. They were not so I'm going to try new spark plugs next

It doesnt spew oil from the headgasket and it only blew white smoke from the exhaust when it happened, I don't think it happened since. Taking it to the shop would be ideal but my car is currently at my friends house so it would need a tow. Did you end up replacing the valve yourself? Was it an easy fix? At this point this seems like the most likely issue, but since I have work I haven't really been able to check it out or make time to have it towed to a shop.

Youre right it is a chain not a belt in the N18 engines

Absolutely. It is a timing chain

 

It is easy just so long as you have the proper tool to remove and install the valves. Removing the front end and putting it all back together is time consuming. Let me know the end result @netj0x

 

I will for sure thank you for the help this will definitely be top of my priority list along with a compression test. Thanks again !

 

Yes I used the wrong term. I know there's the primary timing chain which is critical to valve timing and cylinder operation. There is also a service belt for auxiliary items like the alternator.
That said you guys are right by pointing out that it shouldn't have anything to do with timing in theory. I wish I better recalled what tooth was off by a notch and how changing the belt could have affected the chain. It was just an odd coincidence. I might be wrong in my assessment that they were related. The belt doesn't have teeth... Perhaps they had to reduce the tension on the chain to change the belt. I don't know... I don't have the feeling they touched the chain at the time.

Is it even possible for a chain to skip a tooth? It seems it would be harder than an engine using a timing belt...

 

@TG.

The only way for the timing chain to skip a tooth is either the timing chain tensioner completely fails and you would start to notice all the racket going when going up the hill or the bolt on the hub of the crankshaft gotten loose(not the crankshaft pulley)

 

None of those, so I'm not too sure what it was. What you say makes sense to me.
I should look at my service record. What I do know is that the engine wasn't running properly, rough with a cell. They fixed it and it has run fine ever since.

EDIT:
I did find the service record and it does indicate a timing issue.
" Remove valve cover / check timing and camshaft bearing for wear / restriction that would cause oil pressure loss for Vanos system." ... " Remove valve cover and check timing, found timing 1 tooth out on intake side, corrected timing as per mini instruction"

As to why the the car got out of timing I'm not too sure... That said the engine didn't like it especially at cold start.