Faulty ignition coil give a code?

[chanlon1]

If you have a faulty ignition coil, would it throw a code that would be picked up by a reader?
I'm still looking for the source of a small idling flutter, and wondering if one or more of the coils could be at fault?
New spark plugs were put in at the start of the year.

If a coil is not performing as it should, would you expect a engine light on, or a code to appear?

 

[TheDan]

Typically it would show a code, I believe I've seen people with ignition coil codes on our Z4s. Also usually an ignition coil issue usually causes quite a lot more than an idle flutter.

Other causes of idle flutter I have seen (and tried so far to fix mine) are MAF or vacuum leak.

 

[j3nks79]

You would get a misfire code on a cylinder and it would bring on the engine light.
But it wouldn’t say it’s a coil pack. Just misfire.
You would then swap it to a different cylinder to see if fault follows. If it does then it’s the coil pack. If not you would look at plugs/injector/wiring etc

 

[Rockhopper]

I think i read somewhere that only a certain number of continuous misfires will trigger a fault code. Can't recall how many though.

 

[chanlon1]

Thanks. I am not experiencing any misfires, and no engine lights have come on. I did make up a homemade smoke tester and tried it, but no obvious leaks appeared.
In saying that, I maybe didn't do it correctly.

As for the MAF. Other than getting another, is there any way you can test it or identify that it may be faulty?

 

[enuff_zed]

As for the MAF. Other than getting another, is there any way you can test it or identify that it may be faulty?

If you unplug it the DME should run on a default setting. So if the MAF was faulty you should see the flutter disappear until you plug it back in.

 

[chanlon1]

As for the MAF. Other than getting another, is there any way you can test it or identify that it may be faulty?

If you unplug it the DME should run on a default setting. So if the MAF was faulty you should see the flutter disappear until you plug it back in.

Cool. Thanks. Will look at giving that a go.

 

[Z4Mariner]

Chanlon1, I'm following your thread, since I too have a 'silver top' N52. And I agree that a bad coil will not give its own code, and that an intermittent bad coil will have to get bad enough to cross the EML threshold for allowable missfires before it will set the EML.

Since I once owned an E46 with an M54 engine, I have been "conditioned" to look for a vacuum leak behind every little stumble - real or imagined. I now have nearly 105K miles on my coupe, and I'm planning to replace my CCV (PCV) valve & hoses this coming winter, together with a new starter, thinking that it'll all be easier with the intake manifold off. It's a long shot that your problem is related to CCV, but have you renewed yours yet ? I may be "over-maintaining", replacing mine without real symptoms so far, but I like to do the maintenance in the Winter so I don't have to do much other than tire pressures and oil changes during the Summer.

 

[chanlon1]

Chanlon1, I'm following your thread, since I too have a 'silver top' N52. And I agree that a bad coil will not give its own code, and that an intermittent bad coil will have to get bad enough to cross the EML threshold for allowable missfires before it will set the EML.

Since I once owned an E46 with an M54 engine, I have been "conditioned" to look for a vacuum leak behind every little stumble - real or imagined. I now have nearly 105K miles on my coupe, and I'm planning to replace my CCV (PCV) valve & hoses this coming winter, together with a new starter, thinking that it'll all be easier with the intake manifold off. It's a long shot that your problem is related to CCV, but have you renewed yours yet ? I may be "over-maintaining", replacing mine without real symptoms so far, but I like to do the maintenance in the Winter so I don't have to do much other than tire pressures and oil changes during the Summer.

Hi, I haven’t replaced the CCV “yet”. I did have the Intake manifold partially off a couple months ago when I changed the starter motor, but was able to do it without fully taking the manifold off. The reason I didn’t take it fully off was due to one hose that looked as if it returned from the rocker cover back down towards the sump. I was able to disconnect it at the rocker end, but just couldn’t get to the other end. I guess if I was going to replace it I could just cut it??
Are you aware of any way of knowing if the CCV could be at fault?

 

[Z4Mariner]

I don't have a specific "decison tree" that would point to the CCV, except that as they fail they can put oil into the intake or leak vacuum. Either of those conditions could give some subtle fuel trim or missfire issues that one might notice before they are severe enough to set the EML (CEL). My issues with CCV and other vacuum leaks in my M54 days made me ask.

A Google search for "N52 flutter" or "N52 hesitation" landed me on some E90 threads for which the CCV oiled up DISA's and spark plugs.

 

[chanlon1]

I am pretty sure that the larger of the two DISA's is accessible just above the throttle body and can be removed without taking the manifold off, so its maybe another thing to take a look at, however the N52 DISA's I dont believe are as big an issue as some of the others. The smaller one is under the manifold, so it would need to come off.

Its times like this that you wish the car would throw an error code to make life simple

 

[j3nks79]

This could be down to vanos check valves. Vanos solenoids. Vac leak. Plugs.
Trial and error without a code tho

 

[Mike6]

Could it be the idle control valve that needs cleaning. Not something I have had to do but am sure I have read that that can cause stumbling.

 

[chanlon1]

Never heard of the idle control valve, but the name sounds ominous!
Will need to research it.

 

[enuff_zed]

Never heard of the idle control valve, but the name sounds ominous!
Will need to research it.

I think that's more an M54 issue isn't it?

 

[chanlon1]

I pulled all the coil packs out and there’s no oil visible, so I’m happy the gasket I put in has done its job.
Was going to pull the MAF sensor but the rain came on…..