Problem of the Day: No Start. WTF?

[BimmerM3inGA]

So if you've seen any of my other posts, you'll know that last summer I bought a 2002 X5 4.6is that was supposed to be in excellent condition and to serve as my daily driver. However, it has quite literally been one problem after another and I've barely been able to put 2,000 miles on it because of all the problems.

Well, I guess I got cocky because I've been driving it to work once a week thinking that it was actually going to be reliable enough to, you know, drive to work.

My two-week lucky streak ended today. I got in it to head out and it won't start. Everything lights up and switches on when I turn on the key, but nothing happens when I turn it to the start position. I mean nothing. There is no click, the lights don't dim. Nothing happens.

It has a brand new battery - just installed it last weekend. Is the PNP switch known to be problematic in these cars? I've never had a problem with one in a BMW before. But this car has never disappointed when it comes to having unusual (and common) problems. So I can't rule out that possibility.

I really do need to use it over the weekend, so I need to get this sorted asap. Does anyone have a suggestion that I could try? Is there a reliable troubleshooting routine that would help narrow down the possibilities?

On a side note, I sold my 740i M Sport last night because I thought I finally has this POS running reliably and didn't need it as a backup vehicle. I think that once I figure whatever the hell is wrong with it this time, I'm going to sell this one and look for another E39 Touring. But I won't try to sell it here!

[StephenVA]

Starting point for Diagnostics
If there is nothing when the key is inverted and turned, then it should be in the Ignition switch it self. Try moving the tilt wheel up and down and see if it allows the vehicle to start. If no, then replace the switch.
If however, the dash lights up, and the vehicle just does not engage the starter then look downstream from the ignition switch to the relays and the starter itself.

It it just a question of where is the break in the circuit. When the key is turned, primary voltage moves to everything waiting on the starter to engage, (Injectors, sensors, coil packs, etc). If you do not hear the injectors, and all the clicks under the hood, then double check the ignition relay that it indeed is functional and it is not the culprit. Common issue

[BimmerM3inGA]

Man, I really don't want to just start throwing parts at it…

You're saying the starter relay is a common failure? If so, I can swap that fairly easily. It's worth a try.

Doesn't a failing ignition switch usually have other symptoms? Other than the no start today, everything else seems normal.

[4.8isX5]

This is worth a shot as ive heard from other enthusiasts it can fix electrical gremlins that are random, ive tried it myself once and it worked. Mine was driving down the road and stereo started cutting in and out, then my nav unit started turning on and off on its own and half opening/half closing would not stop even if i turned the car off...

Got to the battery in the trunk undid the positive and negative terminals then i touched them together for 10 sec (apparently resets the modules etc) hooked the batt up everything working fine.

[CoopC]

It sounds like the ignition switch is working fine since the electronics are powering up when you turn the key. The lack of dimming lights, etc. indicates that the starter is not drawing from the battery. I had a similar situation last year with my 740i Sport and it turned out to be a bad starter.

Have you checked to see if there are any stored codes? The DME will store a code when it tries to engage the starter and fails. This code will not trigger a CEL. If the code is stored this will rule out the ignition switch from being bad. Alternatively, you may be able to activate the starter if you have INPA available to you.

It's possible the starter relay could be a problem but it's more likely to be the starter itself. A quick test of the starter would require getting under the car, remove the electrical connector from the starter then apply 12v to the connector pin on the starter. This is can be done by jumpering from the hot cable to the pin. Just give the pin a few taps with the jumper wire and see if the starter turns. The starter should turn immediately when you jumper it. If it is not turning then remove the jumper wire because the starter is shorted and the wire will get hot very fast!

You can also test the starter relay by checking for 12v at the electrical connector when trying to start the vehicle. You will probably need a second person to turn the key over since you will need to be under the car to test for voltage. The 12v will indicate that the relay is working and providing a signal to the starter.

[StephenVA]

I missed your post about everything works except the starter does not spin. Starter itself or the relay. Testing the voltages at the starter and jumping the starter are the only true tests. The reset mentioned above (Battery cables) is like a reboot for your home computer. The crossing of the battery cables (AFTER removing them from the Battery) removes all the stored energy everywhere in the circuits.

Trick: Tap on the starter with a mallet with key in the start position, yes you need two people. At times when they go bad they find a dead spot on the winding/armature and need a twist to find a good spot for the brushes to connect. As everything wears the brushes are weaker as the materials wear, carbon spots, etc.

Just double check battery voltage before starting;

[StephenVA]

Good link on E46 forum for the entire process
E46 NO START – list of possible causes - E46Fanatics

[BimmerM3inGA]

Thanks for the suggestions. I guess my plans for the weekend just changed…

[crystalworks]

On a starter than is "stuck"... meaning it's going out and getting weak (brushes or something), a couple of blows with something heavy will usually get it spinning again as a temporary solution until a replacement can be fitted. I have been utilizing this for a month or so on one of my e30's that has a bad starter. You'll need someone to turn the key for you while you try to knock the starter back into life. I use a 3' handle from a floor jack...

The above posts are an excellent way to diagnose as well. The method above is just very quick and easy to try so may want to try it first. No need to go all Schrazenegger on it, just give it a couple of good taps... don't want to bend the starter housing.

[lo_jack]

It doesn't take much off battery charge state to not kick over these cars. Put the battery on a charger and see what happens.

If you can measure voltage across the system, you need to be around 12+ to kick over, in my experience.