Total Power Loss & Thick Black Smoke

[7builder]

I have owned my 2003 X5 3.0D for a few months now and I have been really impressed with the power, acceleration and just how smooth the gearbox is. On Friday I hooked up our caravan for the first time and set sail for the Wye Valley. I began to notice that pulling away from a standing start at junctions and traffic lights it seemed to be low on power for about a second then would pull like a train. I carried on up hill and down dale without a hitch and even the kick down was working perfectly. When we got to the camp site we stopped on a gradient whilst we checked in. When I tried to pull away I had the car in drive and it wouldn't budge at all. The engine wouldn't rev it just bogged downwind thick plumes of black smoke billowed out of the exhaust. In the end I had to reverse onto a flat section and take a run up before it would move forward. After we pitched up we used the car several times during the weekend and it was faultless. Today we hitched up and had to reverse off the pitch up a slight gradient and again the car bogged down and refused to budge and again deposited huge plumes of black smoke all over the camp site. When we finally got moving and out onto the main roads and motor ways all was well on the journey home. I have never experienced anything like this before and Google hasn't helped to shed light on the possible reasons. Can anyone suggest what the problem might be or am I going to have to spend all of my caravan holidays in Lincolnshire or Holland?

[X5Sport]

Not something daft like the overrun brakes on the caravan locking up by any chance?  Unless your van weighs something silly I can't think of any obvious reason for what you experienced.

Any warning lights at all?  Are all the vacuum hoses connected and intact?  Loss of vacuum could result in lack of turbo assist which will drop your power a fair bit.  Several members have had power loss following a vacuum failure - especially just after a service where the technician forgot to reconnect everything!  :doh:

Richard

[7builder]

It happened not only when trying to move forward but also when reversing so not sure if it would be overrun brakes. I have embarrassingly left the handbrake on before and still pulled away ok albeit with a 300TDi Discovery so would have thought the X5 would have been fine even if the brakes were stuck on.
I will check for split or loose hoses but it is fine usually. Someone has suggested it could be the EGR valve but I'm not convinced. We are not talking about being down on power here but a total loss i.e. not moving anywhere like it has been chained to a tree, a bloody big one.

[Horizon]

If it's running ok now, remove the vacuum hose from the EGR valve and plug it so the vacuum is intact, see if it happens again.
EGR valve may be sticking open, the EGR valves on the E53 are mechanical, so won't throw a fault light on.
They are easy to remove and clean with carb cleaner if needed.

[7builder]

Thanks Horizon I'll try what you suggest with the vacuum hose and see what happens. I might remove the EGR valve and clean it anyway as I bet it needs doing.

[Steamyrotter]

I tow a 1760kg Twin Axle with mine (When it goes) and never experienced anything like that..

Has it got the OEM towing wiring kit or a light bypass kit??
Just a thought as if you have the full integration it may be affecting the engine settings??
(Seem to remember the towing module will tell the car there is extra load and therefore would need a tweak!)

Try pulling off with the caravan on teh back, but the electrics unplugged and see if it does the same...
If nothing else is an easy and cheap thing to try..

[7builder]

Thanks Steamy my car has an aftermarket wiring system installed by a company called PCT and it isn't fully integrated. I was planning on swapping it out for an OEM wiring harness as the existing one buzzes when you indicate (as it should) but also buzzes continuously when you brake or when you turn the headlights on. For this reason alone it is on my to-do list but I thought the OEM electrics would adjust the air suspension if fitted and switch off the parking sensors only. I didn't realise it made adjustments to the engine management system as well.
Tonight I will do an inspection for split hoses, loose connectors and cracked manifolds and plug in a fault code reader to see if it reports any issues with things like EGR or MAF and order up an OEM wiring kit for towing.

[X5Sport]

The 'trailer module' alters the DSC and braking system as well as other functions as it 'tells' the car a trailer of some sort is attached.

It certainly sounds like yours was badly fitted if it's buzzing like a wasp at every use of rear lighting!

Richard

[7builder]

Thanks Richard I'm going to order an OEM trailer module today for sure and swap it out for the abortion I currently have installed. I will also carry out the other checks mentioned above for peace of mind. I did plan on doing that last night but the weather decided differently.

Paul

[TimX5]

[quote="7builder"]
Thanks Richard I'm going to order an OEM trailer module today for sure and swap it out for the abortion I currently have installed. I will also carry out the other checks mentioned above for peace of mind. I did plan on doing that last night but the weather decided differently.

Paul
[/quote]

I bought my towbar electrics from pfjones and when it arrived it was a genuine bmw kit and cost was £78 inc vat .

[7builder]

Hi Tim,
I've just ordered the very same kit. I hope to have it installed this Saturday.

[Steamyrotter]

Just hope the old install hasn't affected too much and is fully reversible.

Sounds like it was installed by a right muppet who didn't really appreciate what modern electrics are like..

[7builder]

[quote="Steamyrotter"]
Just hope the old install hasn't affected too much and is fully reversible.

Sounds like it was installed by a right muppet who didn't really appreciate what modern electrics are like..
[/quote]
We'll after yesterday's storms I managed to remove the abortion of an installation by a previous owner and installed the towing electrics from PF Jones. I must say how easy it was to do and noticed the modules and parts came in bags with BMW part numbers on so obviously OEM kit.  When complete I hooked up to the caravan and tested functionality and everything worked straight off. I was however getting a check brake lights message on the dash so thought I had screwed something up when unpicking the abortion but the wife said that message had been there since Friday. I replaced the bulb but the brake light still doesn't work so I have another issue to add to the list requiring further investigation. Not sure if the new electrics have fixed the original issue yet as I haven't had a chance to take the caravan for a spin.
Oh we'll onward and upward 

[Sanj]

Well done!

The rear lights will be the holder to the bulb needing a good clean up. Common failure.

[7builder]

[quote="Sanj"]
Well done!

The rear lights will be the holder to the bulb needing a good clean up. Common failure.
[/quote]
Thanks for the tip Sanj. I have a fiberglass filament pen for cleaning contacts. I cleaned the bulb holder contacts as well as the metal tracks in the main light cluster and hey presto, fully operational lights again. 
I just wish I had worn latex gloves as I now have tiny little shards of fiberglass between my fingers driving me to distraction.  :noexpression: :blink: :noexpression: