Blown Coil pack leads to DME / ECU failure

[h4pry]

****Go to page 2/3 for actual problem***

I think….

This problem has been discussed extensively, however I think the variable valve system on my M Coupe is just about dead. No oil leak, no low level oil and if I can help it never over 3k revs when cold. However On Saturday I noticed the MC had a very lumpy rough idle to the point that acoustically it sounds like the exhaust is blowing. The car also shakes noticeably under light acceleration and very jerky at low revs when changing from first to second.

When under the bonnet and applying throttle this rough jerky tappet sound is undoubtedly coming from the vanos area. The car seems to be down noticeably on power and it is drinking Optimax like there's no tomorrow.

Car booked into the dealer for Thursday…..3rd party warranty runs out in three weeks…

Feck!

[h4pry]

Just had another listen to it and it sounds like one of the gears inside is mega noisy.

[petecossie]

Hope you get it sorted, doesn't sound good and symptoms point to the Vanos. At least you have 3rd party warranty, I take you have looked in the small print to make sure you're covered OK? Could be the solenoids maybe? I sure someone who has experienced this will come on this thread to give more info as to whether they think it's gears etc or just the soleniods.

[c_w]

From the symptoms I wouldn't rule out a misfire.

Were the gears noisy before? as from what I've gathered they generally get noisy through their lifetime rather than noisy all of a suden.

[h4pry]

From the symptoms I wouldn't rule out a misfire.

Were the gears noisy before? as from what I've gathered they generally get noisy through their lifetime rather than noisy all of a suden.


It just developed over the weekend. It does also feel like a misfire but from inside the car sounds like a blowing exhaust, however as mentioned when manually reving it from under the bonnet the sound is deffinately coming from the vanos.

I've also had the car in the air this morning and the exhaust system visually looks OK.

Were you thinking along the lines that it could be one of the coil packs?

[MGR]

That sucks - hope it turns out to be something cheap :thumbsup:

[Manic]

Sorry to hear about it. I just had exactly this experience, and it was the vanos, unfortunately.

Took a few days for the new vanos to arrive, so I was told not to take the car above 3000 rpm, but otherwise okay to drive. No oil leaks, but the lumpy idle was a bitch.

See my experience here:
http://www.z3mcoupe.com/forum/showthread.php?t=6266

Good luck.

[h4pry]

Well, after 2 1/2 days with the dealer he came back this afternoon and said that the coil pack on number 6 was burnt out! They offered to replace the coil pack (they had one in stock) at a cost of £200+vat but warned that this might not cure the problem.

So I thought £200 doesn't sound too bad and gave them the go ahead.

Two hours later dealer called me back to report that the CP has been changed but the fault is still there / manifesting. They are now suspecting / reporting that the DME is fecked and request my permission for 1hr labour to investigate it.

In a passing comment at the end of the call the service advisor quoted me that in the event of DME change the cost would be £500 + 2hrs labour.

I'll update next week when I hear more...Moreover I'll update the title of this thread when I know exactly what the problem is.

[UJM3]

Man really sorry to hear about the trouble your facing (its a worry in the back of my mind too)

My concern would be with that dealer replacing the coil pack. if it was just misfiring on number 6 could they not of taken the coil pack out with the plug attached and ran the angine to see if the plug fired? That would of shown up if the coil pack was faulty.

I know its a bit late now, but im always concerned with dealers who do the "well try this" approach..i've had it before and wouldn't let them near my car again.

Would you consider taking the car out and bringing it to a specialist?

[SilentBob]

Hi Mate,

If you do decide to take the car to a cheeper specialist I can 100% reccommend MJF engineering in Dorking. From your sig your in Kent so Surrey not to far away. Not much he doesnt know about M engines so may even be worth a call, they are pretty friendly and genuine enthusiasts.

Contact details are:

MJF engineering
Mark: 01306 713232
Unit 1a Oak Down
Horsham Road,
Beare Green
Surrey RH5 4PF

Cheers
Matt

[h4pry]

Hi Mate,

If you do decide to take the car to a cheeper specialist I can 100% reccommend MJF engineering in Dorking. From your sig your in Kent so Surrey not to far away. Not much he doesnt know about M engines so may even be worth a call, they are pretty friendly and genuine enthusiasts.

Contact details are:

MJF engineering
Mark: 01306 713232
Unit 1a Oak Down
Horsham Road,
Beare Green
Surrey RH5 4PF

Cheers
Matt


Thanks for that.

Yes, indeed if this thing gets out of hand and the warranty won't cover it I'll certainly be calling them or even ML / Thorney...

I still have a funny feeling that #5 big end is the problem.

[h4pry]

Here's the latest update:

Dealer has confirmed today that the pin out on the DME to the suspect CP is non active and thus appears to have been damaged (either chip or track).

So the car needs a new DME. But, here's the unsurprising bombshell:

Warranty company will pay for the new CP but not the DME as the damage is consiquential (failed CP has lead to damaging the DME). It seems my fortunate previous dealings with motorcare warranties has come to an end.

Moving on I am very reluctant to actually pay the dealer nearly £800 for this work / dme parts. So, I fortunately have a friend that is willing to help me attempt repairing my DME by actually replacing the driver chip or replacing the DME with another used unit out of an M3 evo. If we are to source another used unit we'll need to realign it with the ews using carsoft...

One half of me says pay the dealer and just be done with it...The other half is quite intrigued to see if this repair / used replacement can actually be done...

I'll sleep on it.:D

[MGR]

Not sure but you may have problems if you are keeping it in the BMW service network in terms of servicing as the computer will think its an M3 and all of the programs / updates etc will be M3 based as its all automatic now.

If you are not might be worth it.

Can't you just pick up a 2nd hand one from a crashed car ?

I think I'd just sort it properly either with a new one or a 2nd hand one.

Also one thing to note is the older DME things have a limited number of update s they can have before they have to be replaced. I think it is 15 so if getting a 2nd hand one then be aware of this.

[h4pry]

Not sure but you may have problems if you are keeping it in the BMW service network in terms of servicing as the computer will think its an M3 and all of the programs / updates etc will be M3 based as its all automatic now.

If you are not might be worth it.

Can't you just pick up a 2nd hand one from a crashed car ?

I think I'd just sort it properly either with a new one or a 2nd hand one.

Also one thing to note is the older DME things have a limited number of update s they can have before they have to be replaced. I think it is 15 so if getting a 2nd hand one then be aware of this.

I will be trying to pick one up from a crashed car however evo's are much more popular than S50's...Same part number anyway.

In the event of fitting a replacement unit, in theory I should be able to download all of the settings / software from my DME/ECU and upload them to a "clean" new/used unit.

Advised that - Keys are hard coded to the EWS module, not the ECU. Each EWS module contains an ISN (individual serial number). When you replace an ECU, you need to program this ISN into the new ECU (the alignment process), or the ECU/EWS will not talk.

[maahny]

It is pretty straight forward replacing with a 2nd hand ECU and aligning the EWS with Autologic or the like. You should be able to get someone to do this for you for about £70.

I'm not sure how true the 15 updates thing is - I have written (remaps) to my old ECU and some customers ECU's far more than 15 times without any issues.

M3 EVO maps and MC maps are identical so you are fine using an ECU from an Evo. If you get stuck finding one let me know - I'm sure I will know someone that has one knocking around.

[MGR]

I'm not sure how true the 15 updates thing is - I have written (remaps) to my old ECU and some customers ECU's far more than 15 times without any issues.


Its defintely right - I guess it just applies to some older cars its not true of the newer cars. Maybe the M style ones are better anyway so even an old M DME will be ok.

[c_w]

When you hook up a diagnostics machine to the car, is it the engine ECU it talks to for related error codes (for all faults, ie airbag etc) or is there another central ECU for general diagnostics? What happens when they are not "aligned" will the car just not start?

[maahny]

When you hook up a diagnostics machine to the car, is it the engine ECU it talks to for related error codes (for all faults, ie airbag etc) or is there another central ECU for general diagnostics? What happens when they are not "aligned" will the car just not start?

Yes it speaks to the ECU - the ECU itself contains more than the software to run the engine.

If the EWS is not aligned the car will not start.

[c_w]

Yes it speaks to the ECU - the ECU itself contains more than the software to run the engine.

If the EWS is not aligned the car will not start.

Sorry to hijack; Maahny, have you ever come across a car that won't talk to a diagnostics machine, but the car otherwise runs fine? Cos I can't get mine to communicate with any diagnostic machines (tried 3 on it now), but nothing else seems up. I got an airbag light on last year that I tried to reset (this is what highlighted the problem; the airbag light is still on as it won't communicate with the car).

[maahny]

Sorry to hijack; Maahny, have you ever come across a car that won't talk to a diagnostics machine, but the car otherwise runs fine? Cos I can't get mine to communicate with any diagnostic machines (tried 3 on it now), but nothing else seems up. I got an airbag light on last year that I tried to reset (this is what highlighted the problem; the airbag light is still on as it won't communicate with the car).


Not had that problem on a BMW but have had it with a Seat. If BMW dealer diagnostic or Autologic doesnt communicate with it I would wonder what is causing the issue.

[h4pry]

Here's the latest update:

Last weekend we plugged in to the car using an OBD socket and inteface - combined with carsoft running off a laptop. The Carsoft was easily able to read the cars fault codes from the original DME and new DME when installed. We cleared the fault codes and began to initiate the alignment process with the EWS module.

Removal of the old damaged DME/ECU and replaced it with the unit from the E36 M3 evo that I sourced. They are identical in every way....

Removal of the old unit:

http://evospeed.co.uk/photo16012008122240/1213019339.jpg



The DME's have a huge connection inteface that just simply unclips.


http://evospeed.co.uk/photo16012008122240/1213019353.jpg



The laptop that is running carsoft plugs into the OBD port in the engine bay.


http://evospeed.co.uk/photo16012008122240/1213019378.jpg




At the end of all of this we hit a big snag in that carsoft just refused to run the ISN alignment with the new DME. Following this I did some research and found that I am not the first person encounter the problem with Carsoft / BMW alignment. It seems to do this alignment I would need to use autologic or a dealer Modic.

So back to square one! Well not quite. My friend Ian who by trade is an electronics engineer opened my damaged DME and traced the fault back to a specific componant on the board. So I had two choices - I could canibolise the known good DME for the required componant or try and get another damaged unit to canibolise. I was hoping this CP controller inside the DME would be the same on another BMW 6 pot DME however I can confirm that after stripping down a 323 and 328 DME they are different.

In the meantime ebay turned up trumps (well hopefully) and I've bought this:D. (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=160246435569&ssPageName=STRK:MEWN:IT&ih=006) SO the idea in theory is to take the damaged coil controller from my DME and fit the good one from the ebay DME.

The car ATM is declared sorn so luckily there is no rush to get this job done.

Next update to follow in due course...




@ Maahny-Do you have autologic at your garage?

[maahny]

No we don't have it - we usually use either Bexleys, Sanspeed or Phil Crouch who all have one. Bexleys and Sanspeed are down Kent way so give them a shout and tell them Imran from Evolve sent you.

[h4pry]

Ok...so job done and car is back on the road.:D

By traceing the resistance across all 6 CP's we were able identify the bad one. Moreover being the last one on the board in theory would dictate that it is for the #6.

We then managed to strip down the spare DME and remove its #6 Coil pack transistor. Then we dismantled my DME and removed the burned out unit and fitted the donor one.

Worked first time.:D Big thanks to my electronics engineer friend:thumbsup:

I will now offer a repair service on DME's that have suffered a similar fate to all S50 forum members.

Here's the pics:

DME out of the car...

http://evospeed.co.uk/photo16012008122240/1214319547.jpg



Pictures of the 6 CP drivers with the heat sink over them...


http://evospeed.co.uk/photo16012008122240/1214319522.jpg



Picture of the defective componant....



http://evospeed.co.uk/photo16012008122240/1214320132.jpg


Thanks for all the replies to this thread.

[h4pry]

Update 30/07/08

Just to report back that after a month or so of driving with my repaired ECU the car is performing brilliantly. Amazing to think that the car was repaired for 99p when the dealer wanted over £1k for fitting a new ECU. Moreover having just had a dealer inspection 1 she is running so smoothly and as such has totally re-inspired my love for the MC.:D

Oversteer and sheer driveability has never been so much fun.

Next on the list for the car is a suspension overhaul.:thumbsup: I'd also like to investigate at some stage my suspicion that the fan / belts etc could do with renewing.

Cheers.

[ghibbett]

Good news and a great thread :thumbsup:

[cragg711220]

Amazing thread, inspiring stuff.


h4pry - Do you remember if you #6 spark plug looked discoloured/sooty or whether it looked fine?

I have similar (perhaps less severe) syptoms but my plugs all look good.