Weird starting problem..

[Flamin'Cow]

Hmm...

Yesterday the car wouldn't start and the OBC was saying 'OIL LEVEL SENSOR + OIL PRESSURE SENSOR - CHECK OWNERS MANUAL' - which I did, it wasnt much help (refer to a BMW specialist).

I checked the oil level - no problems there, but it just kept 'binging' and not allowing me to start.

Eventually (with the assistance of my girlfriend) we managed to bump start the car. I drove straight to my local garage and the mechanic changed my oil for me AND the filter (Castrol GTX3 10w/40w), + topped up the gearbox level and gave the car the once-over - no problems, but he suggested I get a new battery as my one had a dodgy cell. - I like my local mechanic - he only charged me labour for all of that (£20).

Car started fine - drove home - no worries - happy bunny.

Today, car wouldnt start "again" - same thing. 'OIL LEVEL SENSOR + OIL PRESSURE SENSOR - CHECK OWNERS MAUNAL'.

So I went out and got myself a nice new battery (a BIG one) - I have just fitted it and the problem is persisting. Its strange, out of every 10 times I turn the key 6-7 of them I hear the starter motor engage with a loud "CLICK" (defo starter and not solenoid) but it wont turn over and it seems to be this warning message that is stopping the car from starting?

Any ideas where the 'OIL LEVEL' and 'OIL PRESSURE' sensors are? maybe if I found them I could disconnect the bastards! And why are they coming on when I have no Oil leaks, no 'creamy' headgasket blown stuff and my oil level is FINE!

Thanks for your help in advance.

FLAMINCOW

[Flamin'Cow]

Hmmm Okay so I'm working on her atm.....

http://i31.photobucket.com/albums/c392/flamincow/P1010006.jpg

I tunrned the key in the ignition and now the 'OIL PRESSURE SENSOR' warning has gone (no '+' at the end of the warning line)...

http://i31.photobucket.com/albums/c392/flamincow/P1010009.jpg

She's just saying 'OIL LEVEL SENSOR' now with the old 'OWNERS MANUAL'.

http://i31.photobucket.com/albums/c392/flamincow/P1010007.jpg

I have also tried branching from the battery direct to the starter/solenoid and it 'bings' and says the same thing! I have also tried putting her in gear and then rocking her back and forth (to free up a sticky starter), but that does not have any effect.

PLEASE I think it might rain later and I need to get my car in the garage! - HELP!!!!!!!!!!!!!!!!!!!!

Kindest regards

FLAMINCOW

[Flamin'Cow]

Okay,

Been playinmg around with her for a while now. If I remove the +pos wire (small one) from the bottom connection on the starter solenoid then try and start, the warning messages DO NOT APPEAR (but obviously it doesn't start). Then when I reconnect that +pos and try to start 'OIL LEVEL SENSOR' comes on, and it comes on with the '+' for a split second then that goes off. Then when I take the key OUT of the ignition, the '+' is back with 'OIL PRESSURE SENSOR' warning.....

Grrrrrrrrrrrrrrrrrrrrrrrrrrrr This car is REALLY starting to piss me off.....

Kind regards

Flamin'Cow

[SnakeyesTx]

Even if the sensor is bad... is that something that would interrupt the starting circuit? Just seems like a separate issue causing your problem :(

[Felixdacat]

When you turn the Ignition, do you get voltage to the starter?

[Flamin'Cow]

Yes.

Sometimes it even tries to crank but stops after a quick 'click'.

[SnakeyesTx]

Starter relay or starter solenid? Is it a manual? Try push starting?

[Flamin'Cow]

Okay so she 'usually' push-starts (yes its maunal) had a new starter relay and solenoid installed 2 weeks ago (as was not starting, but that seemed to cure the problem) - I managed to push start before. she started on the key then 3 or 4 times, but each time the starter didn't sound 'right'. Kinda clicking a bit before it engaged. After the 4th start on the key, she 'clicked' and the whole 'OIL LEVEL SENSOR + OIL PRESSURE SENSOR' lights came up.....

[Flamin'Cow]

Right,

I've just taken the starter motor off, cleaned & greased it, and then re-installed it. I'm ****in' filthy and its 11:30 PM!

I tried the key in the ignition and held it on 'start' - I got a long series of about 10-15 loud 'clicks' from the starter "tica-tica-tica-tica", like it was trying to turn over, but the engine was not turning over (no fan/belt movement) and after the 15th or so click the 'OIL LEVEL SENSOR' check came up on the control panel and it stopped clicking. I tried again, this time I got about 4 or so 'clicks' in a row from the starter, then the message. Tried AGAIN, got one 'click' then back to the same message again.

I'm gonna go trace the wires now and make sure everything is okay there....any suggestions?

[SnakeyesTx]

Battery! Use one of those chargers that have the 80amp start option, and try cranking over with that connected on that setting. Your voltage could be 12v but your CCA could be so low that its throwing the computer crazy.

[E34-520iSE]

Bad engine earth?

[silver-e34]

the engine oil light is normal when engine doesnt crank over since there is no oil pressure being generated,computer thinks engine is cranking but sees no oil pressure so it throws that light on,as for the clicking noises either the battery is not fully charged or you have bad connections to it,clicking comes from fluctuating voltage as from a low battery or frayed cables, a normal starter would click once and hold it if the engine doesnt turn until you release the key ,the most common cause is the ground cable and the main fuse on the strut tower

[Paul in NZ]

Make sure your new battery is fully charged,they often have only a partial charge.

[BillionPa]

can you start the car with a jump?

[Flamin'Cow]

Okay so I'm gonna take the battery off and give it a quick-charge...

I have never tried jumping battery to battery, however I did have the mechanic successfully start the car with a booster-pack connected straight to the starter/solenoid.....that and she usually starts on a 'bump'.

I'll check the earth at the same time too, can you advise me where that is and also where the 'main fuse on the strut tower' is - thanks.

FLAMINCOW

[silver-e34]

http://www.bmwe34.net/e34main/maintenance/electrical/Data/fuse_link2.jpghttp://www.bmwe34.net/e34main/maintenance/electrical/Data/535i%20fusible%20link.jpgthe first pic is if you have the battery under the hood the second pic is if you have the battery under the back seat

[silver-e34]

if you say your mechanic can start it with a boost pac and when he changed the oil it started fine all day and the next day you had the same problem sounds like something is draining your battery overnight,do a draw test to see if something pulling power when the car is off and work from there

[Flamin'Cow]

thanks for the help. I'm gonna test that fusable link (which is under the rear seat) with a mulitimeter, what should I be looking for? and how can i 'fix' it?

[silver-e34]

http://www.bmwe34.net/e34main/maintenance/electrical/Data/Link.jpgthere is also this one on the positive battery cable its covered with heat shrink and its part of the wire

[Ferret]

If you've got a volmeter handy, check the voltage across your battery terminals as you turn the key. If it only drops half a volt to a volt, you've got a knacked link in the circuit somewhere...

The dreaded click-click-click-clik noise is usually the sound of a flat battery - your solenoid engages, drains the battery, solenoid disengages, battery volts stabilise, repeat.

If your batt's knackered you'll see the volts dive for zero as you turn the key. If it doesent you've probably got a bad earth.

Best way to check if your earths knackered - put your voltmeter (must be voltmeter not ohm meter) between the battery negative and the engine block. Turn the key to start and see if a voltage appears between the engine block... afaik if it's showing anything more than 2-3 volts you've got a buggered earth link. They can cause the flat battery symptoms, as if they heat up their resistance can increase.

You can also check the voltage between the battery pos terminal and the starter pos terminal... which will show a voltage if you've got a partially blown link somewhere. (Again, must be trying to crank)

However, it's more likely that your batt is buggered.

[Flamin'Cow]

The plot thickens....

Just went out there and before starting work I thought "Hell, I just try and start it again" and guess what - she started first time, on the key and no warnings came up.

I turned her on/off a dozen times with no issues.

I took a multi-meter and checked the big fuse in your picture (the one leading from the battery) and across the fuse gives the same reading as if I cross the 2 connectors of the meter.

Furthermore, yesterday I read (on a different website) that if the 'OIL PRESSURE/LEVEL SENSOR' warning comes up, then perhaps you have a fauly sensor. It suggested un-plugging the sensor and seeing if that made any difference. Yesterday - It didn't. I.e. even with the plug disconnected it still read "OIL LEVEL SENSOR + OIL PRESSURE SENSOR - OWNERS HANDBOOK" on the OBC.

NOW - this message is not appearing and the car starts fine. Also, If I un-plug the sensor, the message DOES APPEAR, but the car still starts!......

WHAT THE HELL IS GOING ON! - I'm SUPPOSED TO BE DRIVING TO AMSTERDAM IN 2 WEEKS AND I DONT WANT THE CAR TO 'NOT START' ON THE WAY!

[Ferret]

Dodgy connection somewhere by the sound of it. Check the main earth straps.

I'm wondering if the computers going psycho because of voltage drop? The auto gearbox does it, so you might encounter it with other systems.

[Ausmpower]

You have a bad earth.......Check the earth terminal at the front of the rear seat base (right hand side behind cover) or the battery terminals themselves.

You definately have a voltage drop somewhere.

[Claude]

Dodgy connection somewhere by the sound of it. Check the main earth straps.

I'm wondering if the computers going psycho because of voltage drop? The auto gearbox does it, so you might encounter it with other systems.


Interesting chat, good hints to seek grounding problems.

Question: The section "Ground distribution diagrams" of the Bently manual show and give numbers to the grounding points (where the grounding point is located) for the differents electrical systems, ex: grounding pt / G303; BUT it didn't give info (text) that would say WHERE EXACTLY are located those grounding points

Any hint to relate those grounging points numbers with a specific grounding post location ?

[Paul in NZ]

Make Sure Your Battery Is Completely Charged!

[Ferret]

... and make sure your alternators charging the batt properly.