Hi all, I'm looking for some pointers. Thanks in advance for your expertise.

About 60k miles on the car.

It starts good, sounds nice, no rattling noises or vibrations, revs around 800 RPMs while idling but after a few minutes - around 10 minutes - revs will come up to about 1200 RPMs, engine light appears and throtle response is completely gone.

I measured the voltage across the coolant temperature sensor terminals thinking the problem might be related to temperature. As I start the car voltage between the terminals is about 2.6V, voltage drops little by little and when voltage gets to about 1.9V, car automatically revs up, engine light on, no throttle response.

There seems to be no coolant loses anywhere around.

The engine fan does not start but if I disconnect the coolant temp sensor or turn the AC on, it does work.

Somebody told me the problem might have to do with the throttle body and I blindly bought the idea and order a new one which I should soon receive, yet I now think it's not going to solve anything.

Yesterday I went looking into the water pump... looks fine. I mean, no leaks, it turns freely. What I did notice was that the friction wheel rests against the crank wheel only and does not engage the water pump. If I start the car the friction wheel will be spinning due to the crank wheel moving it but it is still disengaged from the water pump...

so one question for you guys here: as the car is cold, shouldn´t the friction wheel be disengaged from both the crankcase wheel and the water pump? Is it normal for it to be enganging to the crankwheel while the engine is starting to warm up?

I tried to put the friction wheel assembly into service mode by pulling out the tab but it didn´t move and I am afraid to pull to hard and break it, any pointers here?

And well, a last question: what happens as the car gets to normal operating temperature? Is there a sequence of things that should happen? I'm trying to figure that engine light and unresponsive throttle as the car gets to normal operating temperature so I assume something should be happening that is not, thus causing the problem.

I do enormously appreciate your comments; these little cars can carry so much frustration when you know so little about them ....

Thanks to all.

 

I would be looking for a vacuum leak, the vacuum hose going from the rocker cover to the intake manifold is prone to cracking/leaks. It is a PITA to check as it disappears under the intake/filter box. I agree, your throttle body is unlikely to have anything to do with it. The sequence is as the ecu detects temperature rising it puts the solenoid for the friction wheel into action and the waterpump starts to do its thing. From cold it will not be engaged. Whatever is going on, it is nothing to do with the water circulation, that would not induce high revs. Also, you need to read the fault codes to get an idea why the CEL is coming on. Good luck.

 

I beg to differ regarding the water pump! The friction wheel is ALWAYS engaged/jammed between the two pulleys. pulling the tab will release it but you also need to help it out of the jam. when you release the tab, you should push it all the way in. once you start the car, it will jam in place to do its job.

as mentioned above, get the codes checked out.

 

You are wrong, the friction wheel has an electrical connector and is governed by the ecu, it is not engaged whent he engine is cold on my justa. I have witnessed the water pump not turning until operating temp is reached. The tab just moves it even further out so you can get the fan belt off. If your's is perm running then there is something wrong. Try shining a light down there on a cold start and the water pump will be static. My caveat is that non usa models have an electrical friction pulley. US models are always on, this might be our problem here...

 

I never seen the friction wheel with a plug!!! what is the part number for yours or post a link for one, please.

here is mine: https://www.realoem.com/bmw/enUS/par...&q=11287598833

When i worked on my '14 clubman justa, '13 R56 justa, and my friend's 07 or 09 R56 justa, I physically removed this item and they were very basic, no plugs or connectors.
The OP has to look for the presumed connector, i guess, to confirm!

 

https://neominiparts.co.uk/mini-r55-...el-17514-p.asp

Realoem did not show the connector so here it is in all its glory, again, only on Euro models, not USA.

 

It is something to do with emissions that the pump does not engage until the engine is at temperature when the solenoid moves the wheel into postition so non US models are fitted with this, same for F types.

 

aha....no wonder I've never seen it. I assumed the OP is from the States hence my response. Good to know!

 

 

Thank you guys for the comments...

I do have the ECU controlled friction wheel assembly that engages reaching operating temperature; while cold, it's only rubbing against the crankcase pulley. I saw it yesterday, for the first time, engaging the water pump pulley after a few minutes of idle running. Being the first time I see it actually working, kept me thinking it might be faulty somehow; I mean, it should be engaging every time. It does have some transversal movement I noticed while jiggling it a little by hand. As I was looking, I realized the inner rubber ring at the crank wheel is starting to look bitten, so it seems that's something I must be jumping into as soon as I can...

Today I will be checking the codes on the car. I've got a couple of bluetooth interfases which in reviews around were somehow praised as being fit for minis and bmws, yet I find them to be quite inconsistent; even with different apps I tend to get different codes and meanings... Anyhow I'll give it a try today.

I expect the throttle assembly to arrive today and if I have the chance I'll install it. I hope it works, the Bentley manual advises some ECU reprogramming might be needed after intalling it... so I'll let you guys know.

I'll also look for vacuum leaks as Scudder44 recomends; sounds promissing to me.

I do appreciate your inputs. Thanks.

 

I was to replace the throtle body today but as I removed the old assembly, I noticed some liquid oily substance, probably oil, inside the intake manifold. Asuming this not to be a good thing I rather look around for some more information before setting the new throttle body in place. Oil levels are good and no aparent leaking around the engine block. I did had an oil leaking problem but I changed the vacuum pump and that fix it.

Any comments here, much appreciated.

Well, I did scan the car today and the most comprehensive code I got was err A263 - Valvetronic servomotor 1 - along with a few others reporting a misfire in cilinder 10 ( ten ); so, again, I am not that confident in the accuracy of those bluetooth-apps...

Any ideas out there, much appreciated.

 

you might want to try to bleed the coolant system as trapped air around the sensors will give you erroneous readings.

 

Thanks for your comment. I bled the system few days back; actually, I completely replaced the coolant in the car - the car had been running with 100% non diluted coolant for some time now, since the shop I used to take the car to, told me that non diluted coolant was best. When I had this problem with car's throttle not responding, I started reading a little trying to figure out what the cause of it might be, and during that reading I learned something that should had been obvious to me and that is that non diluted coolant was a bad bad idea.

So, now with no trustworthy shop around and 300 miles to the closest dealership, I'm trying to deal with this myself...

 

Thanks for your comment. I bled the system few days back; actually, I completely replaced the coolant in the car - the car had been running with 100% non diluted coolant for some time now, since the shop I used to take the car to, told me that non diluted coolant was best. When I had this problem with car's throttle not responding, I started reading a little trying to figure out what the cause of it might be, and during that reading I learned something that should had been obvious to me and that is that non diluted coolant was a bad bad idea.

So, now with no trustworthy shop around and 300 miles to the closest dealership, I'm trying to deal with this myself...

 

no problem bro, anything to help another mini owner. if you look at my other postings, i have a 09 MCS which has a mind blowing surging idle problem myself and im asking for help from this same forum. Your situation is a little unique i think as you have a euro spec car. i could have sworn that second post from scudder-44 didnt know his head from his a$$ but i was quickly proved wrong about the idler engaging or not. lol...
i spent countless hours under the hood watching the motor and temps. i dont know if your car qualifies, but there's a secrete code you can use to display the ecu readings which helps in determining what the computer see's and what it does when it see's that. ie temp when fan starts, initial cooling temp at startup... ect..

on us spec mk-2's, it requires you to hold the odometer button for about 30 seconds or more, read the displayed vin number and add the displayed numbers up to get a number to use to unlock the factory view. go to option 19 and enter the two digit code then go to option 7 to display the engine cooling temp.

its similiar to up up, down down, left right, left right, select start on the old nintendo systems.

i use a cheepish launch cr-7+ scanner which has live data views under the obd2 emissions screen that displays temp, fuel rail pressure and about 30 other fields which is invaluable when trouble shooting while driving.
personally i NEVER troubleshoot while driving since that illegal, but if you wanted to.... lol

anyone out there feel free to correct me if im wrong, but our us spec cars goes from ambient temp up to about 98 or 100 c then opens up the thermostat to cool down. once it hits 106c at most it should start going down. if its sitting on the drive way or your mashing on the turbo's hard, then the ambient air is not enough to effectively cool the motor and so the fan kicks in at that time. it also runs on my car sometimes after a long drive after i turn off the motor. im assuming it cooling the car afterwards.

id recommend you get a scanner and at least get a code as that would provide a lot of insight on whats the car is specifically complaining about when it cuts your power.

 

sorry i didnt see the last post saying you got an a263 code. lemme look that up and see what it says...

 

The A264 code doesnt come up as any valid code for coopers. it might be a factor of the Bluetooth interface you have but here's a good article on valvetronic's troubleshooting. for what its worth, i read the article and its all foreign to me as my n14 motor uses VANOS and has an oil actuated solenoid to controls the valve timing mechanism.

https://www.pelicanparts.com/techart...nic_Faults.htm

 

Thanks again for your comments. You 've just put a smile on my face...

A couple of years back I learned about this system menu and went through it just to check what it was all about. Now tahat I'm dealing with this issue in my car I went and tried it again to access the temp readings but only options 1 and 2 were available, all the other options will kick me out of the system; I thought something had broken, I'll have to deal with that later.... I had totally forgotten about the unlocking step. Reading your comment just felt like an Eureka kind of thing, haha. You made my day, thanks.

I 've just read your post regarding that surging idle problem and I kind of feel it is somehow related to my own little mischief, so I'll keep an eye on your progress there. I wish I can be of help over there but I'm so foreign to car mechanics that at this point I can only comment about my own ordeal. I have decided to keep going trying to fix my car until some specialized tools I can not get my hands on are required or some reprogramming is needed. Maybe you are getting to the point where some computer parameters need to be adjusted...

Again, thanks for the comment, I'll go and check on that system menu. Knowing at what temperature my car breaks shoud let me figure out things better.

 

Bentley Service Manual: 2A63 HO2S Heater Control Circuit ( Bank 1 Sensor 1 ).

From this I would understand that the precatalyst O2 sensor temp doesn´t match the other temp related information getting into the computer but, I do not understand the ECU stalling the car due to a failing 02 sensor.

I've also learned that different BMW engines got different error code meanings, so who's to be trusted?

Any way if this error code makes sense to you, I'll appreciate your input.

 

Am begining to suspect your timing. If you are getting misfires, odd idling, O2 sensor faults and over 60K miles it is entirely possible even on an N12 to have a timing chain issue. Mine was replaced at 58K miles for similar symptoms, did the job myself and saved a bomb. Has yours been replaced? If you can find someone with the dummy tensioner, it is possible to measure the 'stretch' and if over 68mm it is to be replaced. My power returned in spades after replacement (well, as much as a non turbo can). Pelican parts have a how to for measuring the slack.

 

Thanks for the comment. I did read someplace that the timing chain gets the culprit of a lot funky problems that are difficult to diagnose since, even though the chain might already be failing, it won´t manifest itself as faulty - as in making rattling noises - until it is really near a breaking point; so the thought has crossed my mind, adding a fair amount of anxiety since I might not be prepared to do this by myself. Yet - and this might be my autoinmune system talking trying to avoid a major repair - I can not relate the timing chain with the car reving up and loosing throttle input while getting to normal operational temperature. I would assume, since I really dont´t know much, that a failing timing chain will make the car behave inconsistently and the problem I am experiencing is precise and constant: Every time the car gets to a certain temperature, it revs up a little, engine light pops up and throttle input is gone. I now have the means to better chack at what precise temp the car stalls, so as soon as I check that, I'll let you guys know.

I still have my hopes put on your first post in this thread. Now I'm checking over this little oil found at the intake manifold. I want to take it off so I'm figuring out what I need to put everything back together before disassembling the whole thing.

I appreciate your comment. Thank you.

 

Error codes coming from Carista App w/BT Carista adapter. Do they make any sense to anybody?

Motor:
2BE4
2A63 - Valvetronic Servomotor 1
2A53
2E1C - Firing, cylinder 5
2FAA
2B4E - Misfire impairing exhaust emission, several cylinders
2B4B - Cylinder 10 misfire impairing exhaust emission


Comments appreciated.
Cheers