I'm now to both the board and the Mini Cooper. I've traditionally been the American V8 person growing up and have built engines, etc... A few months ago we bought a 2005 MCS with about 145k miles on it. Had a clean carfax and we test drove it, car felt really tight for the mileage and ran great. Went to check the oil more as a hale mary to make sure nothing obvious wrong. Pull out the dipstick, it's not there. The handle was, but no dipstick stick. They had another mini in the lot, we pulled the dipstick out of that to check this one. It was really hard getting the dipstick all the way in, but I did. Oll was full and looked fine. Figured, I'll just get another dipstick when I get home, everything else checked out.

We've since put about 5k miles on it. Computer says it's still another 1800 miles for an oil change. I've checked the oil periodically and it's always been fine, but I noticed the dipstick was a PITA getting it in and out each time.

I say I want to love it, because I love driving it, it's supposed to be my wife's, but I drive it more than her. But here's where the issues start. Soon after getting it home. The drivers side window started not working intermittently for a few days before it just plain stopped working. Not really having time to figure it out, I figured I'd save the project for later when I could see if it was a switch, motor, or "other" problem. Few weeks go by, and suddenly the window starts working again, but almost simultaneously, the car starts getting this weird intermittent idle problem where it wants to stall, and when it does, it completely loses power. Like resets the clock losing power. Sometimes the car would stay "dead" for a couple seconds, but would eventually come back on and run fine.

After a few weeks of that, the driver's side window stopped working again, thankfully it always stops working while it's in the full up position. The good part if one must try to find on, is that the idle/power loss issue seems to have gone away.

Lasts week, while sitting idling for about 5-7 minutes, the ECM tripped a code and stalled (I found out later it was P0638). Restarted, check engine light is on, but seemed to run fine,10 minutes later while driving back to work the EML light kicks on and the car goes into limp home mode. Resetting the codes clears the limp home mode for a couple days before it happens again. Do some research here and see that the problem is not unheard of and fixes range from cleaning the TB, to replacing the complete engine harness. I had noticed looking at about 20 carfaxes when we were looking at buying our mini that engine harness replacement showed up more than a couple times on the service records for Minis.

So last night I started with the easy one and cleaned the throttle body, it was pretty gunky in there. Took it for a test drive and everything seemed fine, no lights or codes. Get in it this morning to drive to work and after about 6 or 7 minutes as I let off the gas to coast over a set of train tracks, the oil pressure light came on. I look over and I'm at 0 psi.

for reasons unknown, I unconsciously hit the gas peddle to rev the engine apparently to see what happens and the oil pressure shoots up to 40-50 psi and the light goes out. Oil temp is still low as today is the first real cold day of the year (temps under 30 degrees F). I'm a mile from a gas station and civilization so I keep the revs up and stay locked on the pressure gauge for the mile. Pull in, check the oil it's fine. No oil burning smell or other bad things coming out of the dipstick tube. I start back up and it runs fine and the pressure seems normal. I decide to pull out and everything seems fine for about 6 minutes. As I'm accelerating onto the highway, I notice that every time I lifted the gas to shift (mind you the engine is still spinning at ~3000) the oil light kicks on, like instantly and the gauge starts dropping, but as soon as I press the gas, the light goes out and the gauge returns to normal. Not like RPM's drop so oil pressure drops, its like the light is connected to the gas peddle and reacts independent of the RPM's and more so to throttle position. I'm assuming that the mini uses a mechanical oil pump and the physics of this don't make sense. You can't go from 40 psi to 0 in 0.4 seconds. Am I incorrect on this assessment? Driving down the highway under throttle doesn't set the light off.

Of course I'm still sort of freaked out, so after work I pull the dipstick again just to make sure I didn't dream it before. Of course dipstick handle comes out and the lower half of the stick is gone again! Car starts fine and idles with normal pressure....until about 5 or 6 minutes into the drive. Does the same thing all over again. Fine under throttle, light kicks on as soon as I lift the peddle, independent of RPMs. Oil temp is normal, car runs normal, no funny smell or smoke coming from the oil filler cap after I got home.

I guess based on all the other electrical problems I've experienced so far its making me think this is just another one. Or the oil pressure switch is dying (or has died.) On the plus side it didn't go into limp home mode. Any one see such wacky electrical problems? Is this heading towards me having to replace the wiring harness? I can do all kinds of mechanical stuff but electrical stuff gives me the heeby jeebies.

p.s. Why does our car seem to consume oil dipsticks like a wear item?

Sorry for the super long post but I felt the background would be important.

Thanks in advance for any thought on these.

 

My oil pressure light came on at idle after oil change (0 oil pressure from gauge) but by as if it was connected to the pedal like yours. Ended up being the wrong oil filter. Also the window regulators on these cars are a regular fix, mine has had 3. And I believe only the Cooper s is infamous for eating dipsticks, there are aftermarket options. Good luck with your problems and I hope you and your wife enjoy the car once they are squared away.

 

Thanks or responding. I'll have to check out the dipstick options. Will hopefully know more this weekend as I'm doing the sensor and oil change after a day of gorging.

 

Sounds like you have at least two broken ends of dipsticks floating around your oil pan (or jammed together at the end of the dipstick tube, which will break each new one...). The oil pickup has pretty small holes, but there are equally narrow passages in the oil pump that could get blocked. If you want a lot of life out of the car, I would consider dropping the pan to clean out the broken bits and replacing the oil pump/front cover. Each is a 2-3 hour DIY jobs if you are so inclined.

Your build date is recent enough it should have the updated oil filter housing. The oil filters should also be the updated version with the plastic cage integrated into the inside of the paper element. The early filters are just paper and rely on a plastic cage that lives in the oil filter housing to keep them from collapsing. If one of those gets installed on your car, it will occlude or bypass unfiltered oil. Neither is great...

 

Well finally pulled the oil pressure sending unit out and it was leaking oil a little bit, put a new one in and did an oil and filter change. The old filter didn't looked crushed or anything. It's all back together and everything is normal now. So looks like it was the sending unit. I did use a borescope to probe the oil pan through the drain hole. Never did find the tip of the dipstick. The first broken dip stick was broken right at the handle so I don't think that entire dip stick made it's way down into the oil pan. Thanks for everyone who responded.