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E46 EML Light, useful tip!

240K views 26 replies 20 participants last post by  Xexygetty_1 
#1 · (Edited by Moderator)
Recently there was a post here regarding the EML light and loss of power on a 318 E46. My wife's car developed the same problem and on a diagnostic computer, it said Valvetronic unit. I phoned BMW and got a huge quote to supply and fit a new unit. I got other varying suggestions one being to try the coil packs!

However, I was on the phone with Mark (BMW breaker Straffan) regarding a different matter and I explained my problem. Straight away he said your problem is an air pipe at the top of the engine underneath the plastic engine cover. He said these pipes are flimsy and often collapse. He was bang on. A similarly sized sturdier pipe from another engine fitted and the car is running fine ever since.

I have put this post here so that people don't
  • (A) get ripped off or
  • (B)don't spend a lot of time and effort chasing a problem!

When your car is being serviced next it would be worth your while to check the condition of the pipe or consider changing it for a sturdier one before the car lets you down.
 
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#7 ·
If you take the plastic cover off the top of the engine you will see a kind of foam type pipe sitting at the top of the engine. My one almost looked like two pipes as it was collapsed in the centre. If your pipe is collapsed you can replace with any similar sized sturdier pipe or a rplacement OEM one for about 40 euros. If this is your problem your car won't run right straight away. You will need to drive it and rev it hard for 15 mins or so until she comes back to normal!
 
#4 ·
I have two in at the moment and neither of them got fixed with this. One had a faulty fuel relay one had a shagged valvetronic motor..... So sometimes they are to blame.
The hose however is a known culprit and BMW released a service advisorey on it.
 
#5 · (Edited by Moderator)
I have two in at the moment and neither of them got fixed with this. One had a faulty fuel relay one had a shagged valvetronic motor..... So sometimes they are to blame.
Agreed, the EML light itself is in no way specific at all. In this thread Warning Lights Galore, a faulty MAF was the cause of the EML light. But, a simple check of the condition of the hose is definitely worth a check before looking at the more expensive causes!

Also, just in case, you are referring to this light
, aren't you? The reason I ask, is because some people assume that this light
, is the Engine Management Light, when it's actually the "Check Engine" light.
 
#6 · (Edited)
After I changed the pipe I was told it would take about 15 to 30 mins for the shit to blow itself out and for the car to gradually start to rev properly. The guy Mark said that when replacing this pipe people expect the car to start running correctly straight away and don't give it enough time and then start changing other more expensive items that don't need changing at all. My diagnostic showed up as a valvetronic unit fault and the local BMW dealer also said that was the problem. I have to admit even after I was told I expected the car to run well straight away after changing the pipe. After twenty minutes driving and spluttering I thought it has to be the valvetronic unit and ten mins later the revs went up and she started to run smoothly. If I had given up sooner I would have brought it to BMW to replace the valvetronic unit and been convinced that was the problem. Once again thanks to Mark for a top tip and for saving me a small fortune!!
 
#10 ·
EML issues

My 2004 316i was idling rough for a while and then one day the EML and check engine light came on. The car then wouldn't start. It kicks over and almost catches but then dies. I know its not the starter and not the battery and from past experience it seems that the engine isn't getting enough air. Sure enough I pulled the plastic cover off and found that the air pipe looked like it was two pipes because of the crease down the middle.

So before I have it towed to a mechanic I thought I would try replacing the pipe. Does anyone have the part number or the actual name of the air pipe so that I can order a replacement part online?

Cheers
 
#11 ·
I would be interested to know also if there is a similar air pipe in the same location on a 6 pot engine? I am beginning to suspect a slight leak or something in my hoses and if this is a simple enough fix then I would like to try it, if of course it can be done on the 325 E46!!
 
#12 ·
316 e46 error lights galore!!!!

Hello. Have a 316 compact. Car started to lose power and check engine light came on. Mech told me that the mass air flow sensor came up on diagnostics. Changed that. Still no better. Checked diag again. Got 2 more errors. Valvetronic adapt. O2 sensor and mass air flow sensor again! Saw thread about pipe under the engine covwr. Had a look and there is a bit of a crease but nothing major. Dont know what to do mow as im afraid of throwing money that i cant afford into the car when it might be a simple pipe needing to be rwplacwd. Anyone any thoughts on this.
 
#23 ·
Vent Hose problems

Hi, I noticed over a period of time that my 2004 BMW 318i was starting to idle a little erratically. I wasn't too worried about it until one day the engine revs started to hunt and I lost power in at low revs. Initially I though it was the ECU going into limp home mode after a battery change. So I coughing up £42 to get the ECU read and reset with little effect.

Over the next few days the fault got much worse. The EML light would come on intermittently and the car would cough and splutter at low revs. Also on occasion the car would stall as soon as I tried to start it. Then wouldn't fire at all for several minutes afterwards.

I started to fear a hefty repair bill until I heard about similar problems being caused by the vent pipe that sits under the inlet manifold cover but runs across the top of the inlet manifold (see pics attached for location of the pipe and what it looks like. It is item 2 on the schematic). Looking at the pipe I couldn't tell that there was anything wrong as the pipe is covered in a soft rubberised sheath but as soon as I squeezed the pipe it was apparent that the rubber hose inside the sheath had deteriorated. When I pulled the pipe off I found that the last inch on either end of the pipe was still quite firm but the central 4 - 5 inches were soft and squidgy. Not only that it also felt sticky inside as if the rubber had vulcanised.

My current situation is that the replacement part is still in the post. In the mean time I cut out the central section of the pipe and replaced it with a small section of steel tubing I had to hand. I could tell more or less straight away that things were better than they had been. I still have problems in that the car can still run a little erratic and once the engine is up to temperature the EML light comes on below 2000 rpm but then goes out once it hits about 2200 rpm. However I think these problems are down to my DIY job being a bit leaky and hope that the fault will go away once the correct part is fitted and a suitable run in time allowed to pass.

One point I'd like to make is that I loathed paying my local garage £42 for what was in the end 5 mins of work to clear fault codes from the ECU. I'm just about to invest £43 in my own OBD meter so I can clear fault codes to my hearts content as well as monitor in real time any issues.

My head tells me that the pipe is the problem but in my heart there is still a nagging doubt that there's more issues left to be found. Only time and a new vent hose will tell.

Does anyone have any idea as to what sort of mileage you can expect from a BMW N42 engine that gets an oil and filter change every 5k - 7k? I'm currently at 110k with only a couple of coil packs and a couple of sets of plugs needing replacing to date?
 

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#24 · (Edited)
It got worse, a lot worse.

Ok, so thing went from bad to worse.

Started the car on Thursday evening only for it to start misfiring like hell. Then the Engine Check Light came on for about 10 seconds and then started to blink on and off and I noticed a blue haze smoke issuing from under the bonnet.

When I had a look it was oil burning off on the exhaust manifold. For some odd reason oil had been leaking out of the oil filler cap. My initial thought was that I'd blown a coil pack or possibly 2 but the oil leaking got me wondering.

So Saturday morning and I've stripped off the rocker cover to have a look before I went and bought some bits, new coils, filters, oil etc. Glad I did because what I've found is that the timing chain guide has broken and it looks very much like the timing chain has jumped.

I had a chat with my local garage, the guy there has always been pretty good with me. He thinks that the miss fire is due to the valves being bent and to replace them, the timing chain & guides plus bolts, gaskets and labour it's going to be close to £1000 :eek:

I've done heads myself in the distant past, an old Rover SD1, Ford Escort and Renault Clio but nothing as complicated as this engine and think I'm out my depth. Is there an easy way to check if the valves are damaged, the only thing I can think of is a compression test? If the valves are ok is it still a major job to get the timing chain replaced, ie head off?

Any advice at this point would be helpful. Otherwise it's going to the scrapheap in the sky.

And the good news, the vent pipe arrived on Friday!!!!
 
#25 ·
Better news

Ok, so after thinking I've written off my engine I had a chat with my brother who's always been handy with a spanner. He advised me to pull the plugs and see of I could turn the crank and if so if it bound at any point or got tight. I did this and to my relief there was no binding or tightness and all valves appeared to be working fine.

I then remembered a post on here about setting piston 1 to TDC by putting a long screwdriver into the spark plug hole and turning the crank until the screwdriver was at it's highest point. Not very scientific and I could have been out by a degree or two but I did it. Rocking the crank back and forth around TDC until it felt about right. I then checked the position of both the inlet and exhaust cams, thanks to the rectangular section on the end of the camshafts. I could see straight away that both of them were out. Inlet by about 1 link of the chain and the exhaust by about 2. This matched what my little diagnostic meter said. Inlet crank out of range, Exhaust crank out of range and a couple of other faults, some of which I believe were to do with the vent pipe.

I removed the cam chain tensioner and was surprised to see how strong he spring still was. With the tensioner out I was able to jump both cams a link or two on the chain so they looked about right. Tensioner back in I did another couple of turns of the crank by hand just to make sure nothing was sticking or hitting each other. The I rebuilt the top of the engine, rocker cover, cables, plugs, coils etc. After connecting the battery I cleared the fault codes and even fitted my new vent hose pipe.

Holding my breath I turned the key and low and behold she started straight away. It sounded like there was still a misfire on one of the cylinders. I checked the diagnostic and this time I only had 3 errors. One to do with the inlet cam being out of range, so it either slipped a little when I started up or I was out by a link on my realignment. However I'm still showing a misfire on cylinder 4, which is a bit annoying. I tried moving the coil pack between 3 and 4 clear the code and started up again with the same result. So compression test next.

However as this is a thread about the vent hose I would like to point out that the car was running a lot smother even with the misfire. The engine wasn't hunting at tick over and all of the other fault codes have cleared and not come back. Which would suggest that the vent pipe was the source of my other problems.
 
#26 · (Edited)
My E46 N42 has thrown up an Engine Light. It's a 04 318Ci with 88k miles. Reading the codes with INPA gives the following

====================================================
E R R O R M E M O R Y R E P O R T
------------------------------------

Date: 04/19/15 12:02:51
ECU: ME9K_NG4
JobStatus: OKAY
Variant: ME9K_NG4
-------------------------------------------------------------------

RESULT: 2 errors in error memory !
-------------------------------------------------------------------

10062 CDKMD - Misfire detection, Checksum failure

10051 CDKMD01 - Misfire detection cyl.3

I have replaced all 4 of the Coil Packs and the Chain Tensioner. I then came across this thread and so I decided to check the vent host. As previously described, the middle of my pipe is spongy and sticky / gluey. However, the most blocked part appeared to be the Angle Connector on the end of the Vent Hose. There appeared to be a large buildup of grit type stuff, which I assume is some sort of solidified oil. It was jet black in colour, like black sand, in oil. I assume it's some sort of carbon type deposit. I cleaned it out as well as I could, just scraping the deposits out with a small flat screwdriver.

I also checked both the Inlet and Exhaust Camshaft Sensors. Both were prefectly clean with just a coating of clean oil on them - signs of a well maintained engine I think.

Unfortunately, there's no great change. The car is idling very rough. Any thoughts or suggestions ?
 
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