Engine cut out problem – E34 518SEi

[CossAir]

I was driving home from work last week when the engine on my E34 518 completely cut out while I was doing 40mph, there was no stuttering or spluttering, the engine just went completely dead. When I tried to indicate to warn other drivers that I was about to stop, I noticed that the indicators also no longer worked (although they did when the hazard switch is selected). A number of internal lights had also turned off – dash cluster lights were all off (besides the odometer LEDs), the stereo was still working and illuminated and the head lights were still on too. Additionally the power steering was not working. When I came to a complete stop I took out the ignition key, replaced it and the car started. While completing my journey home, the same problem occurred one more time.

The following day I popped the bonnet for a layman inspection, but could not see anything loose or out of the ordinary. So, I took the car to my local (usually very reliable) garage for inspection. Unfortunately, they could not seem to replicate the problem, though they did replace a cracked ‘vaccum tube’ and checked and cleaned the engine idle value. They also checked for fault codes, but reported that no codes were logged! They suggested re-testing the car to see if the vacuum tube was causing this issue. Unfortunately it was not and subsequently on driving the car today, I experienced the problem twice, and on one occasion I was able to dip the clutch and restart the engine while still moving.

Has anyone else had a similar problem? Any help would be much appreciated…

With regards to fuel, I filled up last week (full tank) and have about ¾ remaining.

[marti5]

When was is fuel filter last changed? or it could be the pump its self.

[CossAir]

Marti5 thanks for the information, though the fuel filter and pump were fine and the symptoms seemed to indicate an electrical fault.

Anyway, I am pleased to say that it is now fixed and here is the long story that may come in helpful for other owners….

The intermittent problem turned into a continuous problem on Christmas Eve, so I had to call on the services of the AA. They checked it over but couldn’t identify the exact electrical fault (the engine would turn over but not fire!) it was diagnosed as a potential ignition relay problem (they weren’t sure which one) or an alarm fault (Sigma). Anyway we managed to ‘hot wire’ the ignition in the fuse box to get it going again. I then took the car to a garage to get the alarm removed to see if it solved the problem, which unfortunately it didn’t, though at least it was ruled out.
Now today I had a car electrics specialist come and look at the car and typically the fault turned intermittent again! Though while he was doing the diagnostics I was fiddling with the glove compartment (it was coming loose) only to accidently stumble across the fault (the car cut out when I touched the wiring). Behind the glove box is the wiring loom connection plug and the ignition wire (thick green wire) had fractured in the plug and was either occasionally losing connection or shorting, thus the ignition was failing. A quick rewire/re-solder and the problem fixed!! Overall an expensive and time consuming simple fault!

I hope this helps

[marti5]

Glad you got it sorted and thanks for the write-up which I will keep for future reference.