... the car was very sluggish. '03 TD6.

The car has run perfectly throughout the summer until this morning when the temperature was around 3 degrees. It started normally but I soon noticed that it would not go above about 30mph. The engine was sluggish, almost coughing but not quite, and felt like it would cut out and stop if I attempted to put my foot down so had to keep the throttle gently hovered.
After 5 miles, and just 200 yards from my destination, it was fine and running a treat.

Any ideas chaps?  Not Representative!

Last edited by Flunter on 4th Nov 2014 2:03pm. Edited 1 time in total

Diesel waxing? Cloud point of diesel is about 3degrees C. Is your pre-heater kicking in OK? John
2008 Stornoway Grey 3.6 Tdv8 Vogue - SOLD
2005 TD6 Java Black Vogue - Written off!!
GAP iiD BT-Sold

To be honest I don't know. I did notice the message 'Pre Heating' on the dash before I started the car.
Is there a way of knowing if it's working or not?  Not Representative!

At 3 degrees there is no chance it was diesel waxing. Could have been a glitch with the electrics if the battery is on its way out and when you crank the engine it pulls all the voltage out to get the engine going leaving nothing in reserve once it starts.

Modern vehicles are extremely prone to voltage issues and if the battery is not quite up to the job all sort of errors and problems can occur. After checking the battery I would look into fuel pump under the rear wheel, also when was the diesel filter last changed?

Thanks for the replies.

Obviously I can't say for sure that it isn't the battery but a new one was fitted back in April.
And I've only had the car since then, no filters have been fitted.  Not Representative!

Update:

The weather has been mild lately so I've had no issues, but the other morning it was down to 4 degrees. I was concerned that the problem may rear its ugly head again, and there was a touch of frost on the screen, so I started the car and sat for 10 minutes warming it up and defrosting. The RR had started and revved perfectly so I set off to work. 2 miles down the road I got the warning 'DONG' to say the outside temperature had dropped to below 3 degrees, instantly I began to experience a loss of power and the feeling that the engine would die if I put my foot down. It's only a 5 mile jaunt to work so managed to limp the rest of the way.

Now I can't for the life of me see how the temperature sensor should have any bearing on the running of the engine, you guys may well enlighten me, but would there be any detriment to me disconnecting the sensor and hopefully eliminating the problem?

With the weather set to get worse I really need to be able to rely on the RR.   Not Representative!

Any tips?  Not Representative!

I guess from the lack of response that I'm talking through my backside but you're just too polite to say!   Not Representative!

People on this site are extremely knowledgeable and helpful but if no one has any input you probably wont get a reply . So maybe keep the toys in the cot and investigate a little , like is it throwing any fault codes ? 2008 MY Supercharged
Rimini Red / Jet
four zone climate
remote park heater
and no ugly kid windows.
magnus satis quod turpis satis

More likely nobody knows anything - we have not heard of a prob such as this a (and we hear lots.. ).

The ice-warning and outside temp sensor have absolutely nothing to do with the DDE ECM (motor ECU). With a problem so severe, hopefully the car will have thrown a fault code. You should be able to have them checked at an indie specializing in LR or a main dealer. Or pick up a quality OBD2 code reader. Motor and transmission are standard OBD2 (emissions related) values so they can be read by any halfway decent device.

Also do a google with your symptoms and BMW+530d or 330 or 730 or M57. Many BMWs out there, if it is a known prob you should be able to find something.

Or pick up a real diagnostic tool...
 
RRC 2Dr, RRC 4Dr,
P38, and 2 L322s
(wife thinks I'm nuts - prob right, too)

axle wrote:

People on this site are extremely knowledgeable and helpful but if no one has any input you probably wont get a reply . So maybe keep the toys in the cot and investigate a little ,

I am aware of the knowledge of the members on this forum which is why I don't post my issues anywhere else. As it is not my style, my toys always stay well and truly cot side! No faults are being shown, I would have stated them in my first post.


I've done the usual Goggle searches but failed to find any similar problem. If it helps at all, providing the engine doesn't drop below 2000rpm (which generally means Sport mode) and I resist putting my foot down I can maintain around 45 - 50mph, the problem returns if I need to slow or stop for junctions etc, however a quick blip on the accelerator and away I go again.

Thank you both for taking the time.  Not Representative!

Well, I've never had a TD6 but from what you describe I think you can rule out anything electronic due to the lack of fault codes. Similar symptoms have been described for failing fuel lift pumps, split turbocharger hoses etc.

That's not to say all the electronic sensors will generate a fault if they fail, more generally it is the ECU expecting their inputs which log the error. Since you don't have these errors logged it is likely to not be stuff which talks to ECU modules. I would definitely check the mechanical stuff first.

Maybe that helps, maybe not. It's a weird one for sure but it's going to be a case of ruling out all the obvious stuff first I reckon.

I'd go with 47p2 above, fuel filter.
For what it costs to replace it's worth changing just to be sure.

I have been thinking about this problem for a bit now and can't really say that I have a plausible explanation. It sounds like there is a fuel restriction of some sorts that disappears when the engine heats up a bit. Looking at the relatively short time, I would be looking at either fuel filter and pump or maybe some small crack in the inlet tract letting air in and then closing due to the warming up.

My best suggestion is, follow the recommendations above, change the fuel filter, put some fuel system cleaner through. If the fuel pump has never been replaced, it may be worth doing it now, just to be sure as they do have tendency to show very few problems and then just die all of a sudden.

Also a good check of the hoses/pipes of the inlet tract may be a good plan, just to see if there is no false air coming in. Although that could throw up fuel/air mixture related faults and since there are none, this type problem may not be it.

But then again the fuel rail pressure sensor should also start throwing faults if the pressure drops due to flow restrictions of any sort.

It may be that the fault codes are not triggered because the values are not yet within the triggering range but that wouldn't make sense either.

This one is a bit of a difficult problem to diagnose TBH (well for me at least).

Hope the suggestions help.

Also maybe get the various ECUs updated with the latest software, sometimes that can help solving a problem (did for me with the 4.2 SC). MY 2010 5.0 SC Galway green and sand interior!!
Have the Faultmate MSV2 Extreme to be tinkering with the settings etc. !!

I don't know! But if you'll accept some guesses, here I go:

1. Summer diesel. I've never run a diesel car, but I know 'summer' diesel can become too viscous when the temperature drops. Try a different brand or service station.
2. Cold temperature is always hard on the battery. Also, because it's cold, I'll bet you've got lots of heated bits "on." That puts a lot if strain on the battery and alternator. These two are responsible for many a strange error. I'd check that both are healthy and there's no corrosion on the terminals.