N47D20 120d no start. Where to?

[Cammsport 391]

Hi all, recently just bought a 2007 E87 120d.

The car was great. 160,000kms. Well serviced at BMW and another mechanics. Couldn't fault it at all. 

Picked it up from Christchurch and made the 450km journey to the deep south. Car had multiple start stops etc and again, no dramas or faults whatsoever. 

I get up the next day (real cold morning), go to start the new daily aaannnnd... No good. Car cranks but won't fire. I've done a heap of research and figured it was probably the glow plugs or glow plug controller. I got the local mechanic to come and scan the car. Had a heap of random faults which was expected, cleared them and then no faults came up after 2 or 3 attempted starts. I disconnected the battery and waited a minute. Hooked it back up and tried starting again. Read the codes and the only one that came up was 483D Throttle Actuator. No glow plug codes. Fuel pump can be activated and there's fuel at the rail. 

To make matters worse, one of the injectors looked as though it has or had a slight leak due to the varnishing around the top. I tried to pull but couldn't. Tried to reinstall it but the leak was definitely worse. Tried to remove it again and I've cracked the plug on the injector. I'm gutted. 

Anyone have any diesel experience? Know what my next move should be? Any help is hugely appreciated. 

[*Glenn* 855]

Book it in with BMWorkshop Cam

[Cammsport 391]

7 minutes ago, *Glenn* said:

Book it in with BMWorkshop Cam

I honestly would love to cause I've had enough. But we live in Central Otago now. 

[Cammsport 391]

I'll continue to post results from fault finding for a sanity check and to see if it raises any flags for anyone. 

-Fuel pump can be heard priming, fuel pressure at rail, fuel pressure coming back from cylinder via injector leak. We have fuel. 

-9v at the glow plug lead. #1 Glow plug reads 0.6ohms (pretty sure it's 6 and my multimeter is stepping incorrectly, will test the others tomorrow).

-Ether sprayed into intake (not recommended I know) and no combustion. 

-Throttle body is wide open on start. 

 

 

[F10er 65]

Are you able to get hold of any diagnostic software like INPA or ISTA? It would be handy to know the actual pre supply fuel pressure. The pre supply fuel pump maybe working but could be producing low pressure. It should be about 4 bar from memory.

[Cammsport 391]

1 hour ago, F10er said:

Are you able to get hold of any diagnostic software like INPA or ISTA? It would be handy to know the actual pre supply fuel pressure. The pre supply fuel pump maybe working but could be producing low pressure. It should be about 4 bar from memory.

In the process now of downloading/installing ISTA. INPA wasn't compatible with DDE 6.0 (or was it 7.0 🧐

After some more digging (I could be grasping at straws here), the 483d throttle actuator code can be thrown if the engines sensed an over-run on shut down. Basically saying it had to use the throttle body to kill the engine vs the injectors doing it. So my job for the weekend is to strip the intake side of things and get rid of the gunk/soot/oil, clean the egr etc and go from there. Hopefully by then I'll have ISTA running too. 

 

[Cammsport 391]

Finally managed to get ISTA/D! Absolute game changer. 

Read the codes and got the following:

483D  DDE:THROTTLE ACTUATOR 

4A6E  DDE: GLOW PLUG CYLINDER 1 ACTIVATION

A0B3  CAS: STARTER MOTOR, TERMINAL 50

The glow plug cylinder one will be from me probing it to check voltage. The starter one will be from a momentary low voltage. The last one, throttle actuator, ran through the ISTA troubleshooting schedule and it all opened and closed on the commands and tolerances were good. 

Cleared the codes, gave it two long starts again but now no codes are showing 🤯

Checked the supply fuel pressure and the rail pressure and all seems good. 

Unsure what my next move is. I'll see if there's a way to test the injectors. I'm worried there's an issue with the chain, that'd be worst case. 

[F10er 65]

When you're cranking the engine do you see an engine speed signal from the crankshaft sensor in Ista? Also this mighy sound dumb but what's the condition of your battery? Could you post a vid of the engine while cranking? 

[Cammsport 391]

4 hours ago, F10er said:

When you're cranking the engine do you see an engine speed signal from the crankshaft sensor in Ista? Also this mighy sound dumb but what's the condition of your battery? Could you post a vid of the engine while cranking? 

Took a video to answer your post, but yes, RPM signal showing

Battery is as healthy as an older battery can be. It's not new but charges well and holds good voltage. The video shoes 14v due to it being hooked up to the E91 but usually sits around 12.5v.

[Cammsport 391]

Next thing on the list, has the chain snapped? I took out the camshaft position sensor to look at the cam gear. Found the issue.. So I thought. 

By the looks of that, I thought the chain had come off the teeth. Turned it over just to double check. 

I've been so desperate to find something wrong, I wasn't thinking. Back to the fault finding then. 

 

Tested the hall effect cam gear sensor by back probing the socket. All looks to be good. 

Having a rest now. No room in the garage and the snowns coming in. More google/forums/YT it is then. 

[KwS 2429]

Could you get one of those endoscope inspection cameras and poke it in the sensor hole and off to the side and see if the chain is still there?

[Cammsport 391]

21 minutes ago, KwS said:

Could you get one of those endoscope inspection cameras and poke it in the sensor hole and off to the side and see if the chain is still there?

I could do but the chain must be there for the cams to be turning. 

[F10er 65]

Is it logging any glow plug faults now? If it is that maybe your issue with it being so cold down there. It sounds like it is firing when cranking but probably only on 1 or 2 cylinders. 

Edited June 11, 2022 by F10er

[Cammsport 391]

No glow plug codes since I removed and tested that 1 and then reset codes. 

[F10er 65]

You could try testing for voltage at the glow plugs when the ignition is turned on if you haven'talready. The glow plug controllers are a known issue, so it's possible it's not working and/or logging fault codes. 

[Cammsport 391]

23 minutes ago, F10er said:

You could try testing for voltage at the glow plugs when the ignition is turned on if you haven'talready. The glow plug controllers are a known issue, so it's possible it's not working and/or logging fault codes. 

Yip tested. Got about 9v. 6ohms across the glow plug itself 

 

[Allanw 1072]

Does that cranking video sound VERY wrong to anybody else???

It doesn't sound like the compression is correct/evenly spaced.

Compression test and check the cam timing??

 

[E30 325i Rag-Top 2963]

Yes, agree, that doesn’t sound right at all. Our 116d (pretty much same engine) is completely different when cranking.

Yours doesn’t sound like it is turning fast enough to catch and fire.

I would think that is your issue, and not the glow plugs.

[Cammsport 391]

I'll take a better video of the cranking tomorrow for about 10 seconds. I'll do it from the cabin so you can hear it like-for-like for the daily N47 drivers. 

Bad compression from a stretched chain is very plausible on these engines. Just to reiterate, I don't think it is the glow plugs. 

I'll look into the cam timing and compression checks. 

Thanks for the replies by the way. 

[KwS 2429]

5 hours ago, Allanw said:

Does that cranking video sound VERY wrong to anybody else???

It doesn't sound like the compression is correct/evenly spaced.

Compression test and check the cam timing??

 

Only just watched the two cranking ones and it sounds like its cranking far too slow.

[Gaz 1062]

Forget glowplugs, one glowplug isn't going to stop the car from starting 

[Cammsport 391]

I'm buying everyone beers if its the battery. Going to get a new battery tomorrow and give it a crack. Wouldn't be the first time I've looked past something so easy. 

[Cammsport 391]

Might have to hold off for the day. That shed would be handy 😅

[Spinner99 55]

My diesel knowledge hasn't been tested in 20 years so I appreciate things have changed a lot since then so possibly take this suggestion with a grain of salt, but reading your story the thing I keep looking at is it's pretty cold where you are which is really when you want those glow plugs doing their job.  I spotted in your video the engine in cranking before the glow plug light has turned off.  Back in the old days we used to set the ignition to "on" and wait for the glow plug light to turn off before cranking the engine.  If that's not helping, I don't know if you have a way to even give the car a double shot of the glow plugs heating up prior to trying a crank?

[Palazzo 478]

11 hours ago, Cammsport said:

I'm buying everyone beers if its the battery. Going to get a new battery tomorrow and give it a crack. Wouldn't be the first time I've looked past something so easy. 

I’m amazed by what low voltage does in a modern (ish) car. We have an ‘07 Civic, air con stopped working, thought “oh well”, needed a new battery, air con works. I’ve been reading thinking battery because you’re in a colder area, but I’m no guru. Look forward to seeing what the problem is.