Hey, I'm a new member, first thread, help me out! Big post, but all the juicy horrible details.

2007 Mini Cooper Base Model n14 motor DOHC (Believe it's the later year model, as the PCV valve is integrated into the valve cover, not 100% sure if this means this.)
120,xxx miles
Manual 6-speed

Problem?
Rough idle at stops, and will stall out, turning off.

In the morning, after sleeping, or letting the car sit for a while, the car will start, and idle fine, like perfect, no problem, but after driving for a little bit, the car will start idling very rough, and stalling at stops. It use to jerk, or surge, or almost feel like a slip, at higher gears, but isn't anymore, as I had really bad spark plugs replaced, however, they were new plugs i got 2 months ago, so something broke, or fouled them bad. As of right now, my car has:
- NGK laser iridium spark plugs
- New Air filter
- Oil changed
- Fuel system cleaned during oil change, and later a supplement added to fuel system
- high octane gas with ethanol, or 100% gasoline no ethanol used that costs $5.50 at my Chevron.
- Valve cover gasket replaced, as the misfires were 1, and 2, and had fouling, oily, carbony residue on them.
- PCV replaced, purchased via Amazon, as Mini wants you to replace the whole valve cover.
- Car doesn't have a fuel filter
- New Coil Packs Coil-On-Plug
- Mechanic also said the compression was good, within like 5 of each other.
- Haven't done a leak down test, but thinking on doing that
- I have a 8oz bottle of K-Seal to attempt, just in case, to plug any leaks in cooling system including radiator, head gasket, and helps the water pump
- I want to do an oil additive if at all possible to help seal oil gaskets inside etc
- This time i used Lucas formula deep fuel cleaner white bottle, but have used others before

I'm installing, another new set of Coil-on-plug type coil packs tomorrow morning, as i had to replaced the spark plugs twice, first pair weren't NGK laser iridiums, and I felt, perhaps the badly fouled plugs, fouled a coil pack, so that will be changed tomorrow. The PCV valve, and valve cover gasket were replaced today, 3/4/2022. I left the mechanic, ran great, then got to a stop light, and uh-oh, rough idle, stalled, check engine light, Haven't called them back, they are good guys, phenomenal work, but minis, and bmw have some issues to say the least. 2x of the coil packs in it at the moment, are Napa cheap ones, and 2x Bosch, and i heard that Bosch was the original partner in making the minis, and was removed, due to good coil packs causing rough idles, so tomorrow morning, all 4x will be NAPA Echlin coil-on-plugs.

The old owner, changed the valve cover gasket, a month before i bought it, and said oil was leaking into spark plug 1, and 2, which i'm still getting misfires at the moment for these 1, and 2. I thought maybe the PCV failed, and broke the new valve cover gasket, the mechanic said it was hard, and could have some weaker, brittle parts, so i had a Fel-pro valve cover gasket installed.

Also I noticed, when i turn the A/c on, it almost increases the RPMs and makes it idle slightly less bad, but still rough idle, and may even prevent it from stalling out entirely. I found this weird, as I've never heard of an A/c unit doing this. I've heard of the "use your heater on full, if your car over heats" but the a/c works differently, and actually would increase gas, and "work" on the motor.

I saw some oil, on a wire cluster, that was below my oil filter, while looking for leaks, and thought maybe oil from the oil changed got on it, but i also saw at the bottom of the vacuum pump, which is above the oil filter, had some thick oily but gritty material on the underside, and it i wiped it off, and have been looking at it, and not seeing more leaks there. Car also seemed like it was burning oil, about 1 quart every 1000 miles, but now it might not be, but i drive 100 miles a day to work, and i heard Mini, and BMW some times warn of an oil loss, of this exact ratio quart per 1000 miles.

Other than this, i'm stumped. I was thinking fuel pump, Coolant temp sensor, oil sensor, MAF (which i have a junkyard intake that has a MAF i could switch on to test that i suppose) the 1x VANOS sensor, maybe a vacuum Pump, and of course praying it's not a head, head gasket, valve seats, pistons, cylinders, or something basically catastrophic. Was also curious if a fuse, or relay, or cooling fan could be out.

Also, there's no temp gauge, and I'm not sure how to view it in my cluster, if at all possible.

The other day too, i drove to work, the 100 miles, with a/c on, and when i parked, the fan was still on, when car was off, this was a first, but i assumed it was from the A/C since the condenser uses the same fan, but who knows if this is a problem with relay, cooling fan, or sensor.

Please help, if anyone has had similar issues


The old owner said it had a new 60month battery about 1.5 years ago, new valve cover gasket (i just replaced with fel-pro today) thermostat, coolant flushed, something with fixing back, or front brakes would have to look at his recipes.

There is some sludge in the coolant fill tank which kinda worried me but that does happen in older cars i suppose

Please help, i do love the car, and don't want to be upset over a couple thousand dollar repair.

every now and then, my brake light, like e-brake, comes on, even when it's not engaged, with the tire pressure warning light, which is like a circle, with 2 half moons, and then another warning light that's a triangle with a arrow that circles around it. I'm not sure what this is, if my brakes have issues, need fluid, pads, or if this indicates the vacuum pump is having some kind of issue. Also curious about o2 sensors, or catalytic since the plugs were fouled pretty bad.

 

Please help, in a perfect world, i'd clean all the sensors with cleaner, and clean the catalytic and replace the vacuum pump if needed, and pressure test the cooling system, and test everything i can think of. But someone out there might have an idea, or had, or have a similar issue, and thought i'd try to reach out, it's an awesome little car, and I'd like to keep it, but sometimes wonder if i should of got the BRZ/FRS/86 instead, thought I was saving $6000 from buying the BRZ, but now I'm starting to worry.

 

Replaced Coil-on-Plugs today, 3x of 4 were definitely oily from the oil leak before. Mind you, these coil packs were new 3 months ago, but with the oil leak, and other fastly fouled spark plugs, i figured they could of fouled new coil packs as well. All 4x Coil packs have been replaced with NAPA Echlin coil-on-plugs. Idled some better, started better, but eventually the rough idle surged a bit, not to the point of stalling yet, but going to O'Reilly's to pick up a fuel pump relay, just cause it can cause a similar issue, and is cheap, and easy to replace. Also noticed, at idle, parked, in my driveway, not driving anywhere, when idling, if i push on the brake, the RPMs drop slightly, and i thought that was kind of odd. I also noticed condensation in the exhaust pipe tip, and there was a lot of carbon build up on it, but read this is normal, and not to worry. I swear also before oil never got on my oil cap, and now oil is on my oil cap, which may be good, my old car had oil on the cap, but this car, i swear was always dry on the cap, maybe bad pressure previously? like a lack of pressure?

I still want to add K-Seal to my coolant, just to make sure things are sealed, but will need to remove some coolant, cause i don't want to fill it past max, and it's at the max mark now.

Also heard a "thump" every now and then, behind my driver seat, which made me think the noise was either the fuel pump, or a misfire. When i turned the car off, the thump was rapidily repeated thump thump thump, and went away. It use to do this too, but really noticed it now, as I'm searching for any type of issue, leak, sound, from anywhere that could be abnormal.

Also, as mentioned above, sometimes the Brake light comes on, and the ASC triangle with arrow around it, and the tire pressure warning light, and they go away, but could this be a cause of rough idle, and stalling, if part of the ASC system fails? I read the ASC can control the fuel injectors, and stabilize everything. I have a Sport mode button, and ASC Off button, by my shifter, and if you click sport, the light comes on, but no light for the ASC button, so i don't know if it's on, or off. No saved codes other than misfire cylinder 1, and 2. Sad when you're praying for a warning light, and code to pop up, other than the misfire. Maybe a sensor related to the ASC?

Also when changing coil-on-plugs, the wires harness that connects to them had oil, on 1, and 2, which i thought was weird, how does oil reach there, and thought it may have fouled the connector, didn't have any cleaners, but can i replace this easily/cheaply? it connects to a few things, and dont see a disconnect section, unless its in this box, where the wires then go in different directions.

Could my vacuum pump be failing, and if so, does my car use the vacuum pump in its brake system, like brake boosters, and causing a rough idle, as the vacuum pump also relieves pressure?

Please help, i'm getting desperate.

 

Replaced the fuel pump relay, I believe in the engine bay, driver side, it is the bottom relay? 20 amp, 12 volt. Is this right? I switched it, and then i started my car, and turned my A/C on, and switched to heater, and a humming, whinning noise started, that I have never heard before, what is the problem now?! one thing after another?! Does this indicate anything, did I mess something up, is this the wrong relay spot, and wrong relay ratios?! that would be really bad. I noticed today, when I disconnected the battery, two different times, putting the negative cable back on the battery negative, it sparks, and kind of sounds like a noise in the engine area like clicking, or making a noise. Is this an indicator of a short?