2002 E46 Compact 316ti N42 - Crankshaft sensor and vanos problems

[feras24]

Hi, I recently bought my first car for £3000 an Automatic BMW 3 series compact 316ti 2002 E46 with an N42 engine and with 58,000 miles on the clock. I love the car so much but I have encountered some major problems and I really hope this amazing Bimmer community could help me out

First problem is when i'm driving, the red battery light on the dash occasionally comes on for a few seconds with a loss of power and sometimes if i'm in traffic the battery light would come on again and the engine will just switch off, with the battery and oil light displayed. The car will then not switch back on immediately and I will have to wait a few minutes for the car to start back up again (which has made some reallyyy sticky situations!!!). I did some research and it sounds like I have a crankshaft sensor problem but i'm not sure .

So I took my car to my local garage and they were convinced it was nothing to do with crankshaft sensor and did not change it even though they did a diagnostic which came up with crankshaft and camshaft problems but they just cleared it as they thought my problem was due to my engine. Because, they uncovered that my engine oil had all turned to sludge as if the oil had never been changed (although service book states an oil service was carried out just 5,000 miles ago ) and that this was most likely causing my problem. In total they charged me £600 and also put new brakes and discs and they flushed the engine oil and put new oil amongst a few other minor things, which didn't solve my issue

I then had my car back and the next day the battery light flashed up again, so I took my car back to the garage and they then uncovered that I need a new vanos costing £948 so I just took my car back to shop around.

I then took my car to another garage and they told me my problem is my timing chain and tensioner, so he fitted a new timing chain and tensioner for £600 and the car now feels a lot more responsive at accelerating and also to drive in general unlike before, as I noticed it felt a bit sluggish. He also told me that I needed my vanos to be fixed and that my engine oil was sludgy and suggested me to sell the car as even if I flushed the engine a few times, the engine will not last long and more problems will come up :/

However after now spending £1200, my problem of the red battery light flashing with loss of power still persists which is stopping me from driving my car

So, i'm really confused now and if I carry out any more of this trial and error repair work, I would have spent more money on repairs than the car itself. I'm now debating to perhaps just sell the car

I found a quote to repair the vanos for £500 and the crankshaft sensor for around £200 which I would be willing to do but I am not sure if it is worth it as I am concerned about more problems arising due to the sludgy oil, what are your opinions?

I would really like to hear your thoughts as it's my first car and i'm not very knowledgeable about cars....yet

Thanks in advance, i'm proud to be a member of this great community

[Thedonesco]

I had kinda had the same problems let me tell u about them... My battery light kept coming on and off so did my yellow brake light my abs and also my traction contr sensor the gauges would start to go crazy and also my car would sometimes jerk but this problem kept happening on and off so I took it to a shop and they tried to tell all this bs this is what needs to be replace because of this and that every shop telling me different diagnostic so I look online and found nothing... Long story short one day I cleaned my trunk out and found that a small nut got into my battery terminal red side and it made my car go nuts and after I got it off and cleaned by terminals made sure nothing like that would happen again I haven't had a problem... Not saying that this is what's causing you BMW but you might want to check it out Juss to make sure I had simalair problem on my car and Iam not a professional but Juss FOOD FOR THOUGHT...

Also be carefull most likely it's going to sparks if there is anything there and it might not let your car start after Juss unhook the battery for 20mins so the computer resets good luck

[feras24]

Thanks Thedonesco, I also had my yellow brake light and dsc light come on!

That's really interesting that just that small nut caused those problems, i'll have a look at mine and see if i can find anything out of the ordinary, I hope so, it will save me soo much lol!!

Well, I had a look at the battery and the terminals and it looked clean and free of any obstructions

[Thedonesco]

With simalar symptoms there might be some sort of electrical problem maybe lose wire somewhere thats what I think look around and make sure that there isn't any wire making bad contact to make the car act up... That is Juss my opinion and again Iam not a pro but Juss suggesting

[feras24]

Thanks, no worries I really appreciate any help I can get!
I had my battery tested and alternator tested and they were both fine!
I also did a lot of research and i'm convinced it's the crankshaft sensor, so I am gonna buy the part tomorrow and hopefully get it fitted too!
Then, after it's fitted I will take a long drive and watch that battery on the dash like a hawk and hopefully with any luck I won't see it light up again!

[Pumkin Eater]

Thanks, no worries I really appreciate any help I can get!
I had my battery tested and alternator tested and they were both fine!
I also did a lot of research and i'm convinced it's the crankshaft sensor, so I am gonna buy the part tomorrow and hopefully get it fitted too!
Then, after it's fitted I will take a long drive and watch that battery on the dash like a hawk and hopefully with any luck I won't see it light up again!

Were you able to get your car sorted??

[feras24]

Yes, it was indeed the crankshaft sensor in the end and I haven't had any problems since