E46 shut down at 60MPH!!! - BMW Forum

legless-egg · 12-15-2009, 07:17 AM

Hi guys, please help,
My E46 has been shutting itself off while ive been driving, this causes me to loose all power, ABS and PAS so its not good at 60MPH on a carriageway with no hard shoulder!!
Mid way between start up and full running temperature there is a chugging and its slow to pick up the revs when pulling off from the lights. I can get it to stall by tapping the throttle.
The shut off's have all happened just as the engine has come up to temperature and the valve would be opening to circulate the coolant. Having the heater on makes no difference, just puts the shut down back a bit.
I think I have a faulty temperature sensor but there are no fault codes and the garage cant tell which one it is (aparently there are 4 and its about £800 to replace them all) Thats not good either!!!
Ive talked to alot of people and a temperature sensor fault is the common answer but damaged pipes for cold running has also been mentioned as well as a bad earth.
The shut downs are random and anything from a day to about 2 weeks apart. The engine starts and runs fine after 30 mins which is about the time it takes to cool. There has been a brake and traction control light on after restart but these go away when the enginn is turned off and restarted again.

Any help or advice you can give is greatly appreciated as I'm at my wits end!!!

Merry Christmas

roma · 12-15-2009, 08:33 PM

that sound right CTS,have them check the MAS,or fuel pump-regulator

legless-egg · 12-16-2009, 01:36 PM

cheers roma, appreciate the help

FCPGroton · 12-16-2009, 03:39 PM

When the car dies, can you feel it coming, or does it just happen out of no where?

legless-egg · 12-16-2009, 04:16 PM

its completely out of nowhere. your driving along fine, im usually cruising, doing about 60ish in 5th gear on a carriage way, no chugging, warning lights or anything; then the engine just shuts down instantly, every light on the dash comes on and you have no power at all. it'll run fine for days, except for the low power at a certain temp range which i can deal with, its a headache but not really a serious problem if thats all it is. then it'll just suddenly shut down when it hits full running temp.
there was a problem about 6 months ago with the eml light coming on but that was sorted as it was cam shaft sensors.
im pretty sure ive got the n42 (i think) 2l engine which ive found out has alot of issues.

roma · 12-20-2009, 07:37 AM

if those sensors are aftermarket ?they may not work

marti5 · 12-20-2009, 08:20 AM

Could even be as simple as the camshaft sensor agian as non genuine ones are very iffy, but it should have shown that on diag,but only if it was failing under diag, can they do a live diag on the move.

legless-egg · 12-20-2009, 09:11 AM

well the car has completely sh1t itself 4 times this week, random shutdowns but restarts once cooled. got the AA out and their diagnostic showed cam + crank sensors, that was odd as no other diagnostic showed any faults previously although when the ran the test the car still wasn't starting. all other times the car was working. not sure about a live diagnostic but i would have thought that cam + crank faults would have been stored in the memory as they can be pretty serious.
they think the temp issue might be to do with that as well as the metal will expand when warm giving a false reading. not sure what type of cam sensors were fitted last time but i'd hope they were genuine bmw parts cos they cost £200 each to get + fit.
would timing be an issue if it is cam + crank sensors??? the car runs fine tho (when its working!) no lumps, chudders or misfires

marti5 · 12-20-2009, 09:32 AM

The timing will be fine as this is set via the ECU which funny enough takes information for this from the Camshaft sensor, can you remember what code numbers came up on the AA diag. If not it wont be both cam and crank sensor dying, I would very much doubt it, but possibly I dont suppose your anywhere near me Ipswich?? as I have the diag equipment.

legless-egg · 12-20-2009, 10:00 AM

the codes are on the aa form with the car and i cant remember them but ill post them up here when i get it back. the guy that replaced the cam sensors last time says that its prob a crank sensor this time as there was only 1 cam fault and the second cam sensor would take over. not sure if thats right or not tho.
unfortunately im in northern ireland so a spin to ipswich is a bit of a trek, thank for the offer tho!!!

marti5 · 12-20-2009, 10:05 AM

Once you have the codes post them up and I will have a look in my files...I will need the build year and the last 7 digits of your VIN #, you can PM me.

legless-egg · 12-20-2009, 11:12 AM

that'd be great marti, thanks!!!

marti5 · 12-20-2009, 12:59 PM

No worries....I await to hear from you.When I say build year if you look in the engine bay on top of normally the right hand side ( from the rear of the car) suspension tower it will give month/ year....as in 04/94 etc thats what I need and the last 7 digits of VIN #.

legless-egg · 01-03-2010, 01:29 PM

the codes are po335 + po336 cam + crank sensors which were replaced but the car still shuts down. its stopping every time almost exactly when it hits full running temperature and its taken to reving itself all on its own as well. i think its possessed.........engines - white mans magic.
only had the car for half a day so didn't get round to getting the vin number. just thought i'd update this.

marti5 · 01-03-2010, 01:39 PM

Reving on its own.... the MAF will do this, it will also send a message to the ECU and tells it the mixture is incorrect and shuts down ( 60 mph) the system to reset it to default......