Hi.
Our 04 2.0 Turbo Diesel Zafira has just started with some what I will describe as engine rattle.
There is a little bit of history, so I'll begin with that.
Firstly, when starting, the yellow light comes on (car with a spanner through it) I can't right now remember what this indicator is for, is it engine management? Anyway, it always goes out within a minute or less.
There have been occasions whilest driving on the motorways around 70-80mph that the car has for a fraction of a second, lost power and the engine management light has come on. (image of a car with a spanner through it) The car has NOT entered 'limp mode', but continued as though nothing happened. This has happened no more than 5 times in the last 2 years that we have had the car. It has never done it at lower speeds.
About three months ago I noticed that it would not pull as it should. There was no warning signs, just took it out one morning and it simple had no power, just as though the turbo wasn't engaging. I read a few things and decided to replace the air and fuel filters. I also dismantled the EGR valve and cleaned it out, it was full of gunk, but the valve was free moving. (I have subsequently been told that there is a chamber below this that has aroung 8 valves in it, this wasn't cleaned) It didn't solve the problem straight away; it was better, much better, but not quite right. I decided to also add some Redex to the fuel and this seemed to bring back its full performance. It appeared I had sorted the loss of power problem, and the car was able to romp up the hills as it always had.
However, about a month ago, it seemed to lose power again, just wouldn't pull as it usually did. But then the following day it was ok, and for days following it. So the car would run fine for a while and then would have a short time, perhaps half a day with power loss. I did also realise that a very very slight rattle was developing during the occasions in which it wouldn't pull. When the car was performing properly, the rattle would disappear.
But the occasions in which the car ran properly were becoming less frequent, and the rattle as I would describe it, was getting louder, I am tempted to describe it as tapping sometimes. It has been underperforming for around 2 week now continually. But in all this time the car has NEVER entered 'limp mode' or dispayed any warning lights.
Now, what follows maybe important, I'm not sure.
1. There is no rattle when placed in neutral and revved, even at very high revs.
2. The rattle is not as evident in 1st and second gears at any speed or revs. When in 3rd and fourth the rattle becomes much more evident, especially if you floor it, although I can get it to stop rattling if I pull back on the throttle ever so slightly. If I accelerate very, very slowly it does not rattle. Whilst cruising the rattle is not apparent, but there is no pulling power should you require it.
3. I maybe wrong but I seem to remember that the idle speed should be 885rpm. This has dropped to 750rpm, and the engine is more lumpy now whilst in neutral. When first started in the morning it does hold revs at 885rpm for a short while.
4. Fuel comsuption has also decreased. It may be my imagination but I thought we could get around 550 - 600 miles to a 60L tank. (45mpg) combined. Now we only get around 415 (31mpg) I maybe wrong though. You other Zaf drivers will know what's about right.
Now the mystery continues. Two days ago I took it on the motorway and placed it third gear and drove for around 15 miles at around 3500-4000 rpms. Read that others had done this with success. No such joy for me.
However, today I took it out and accelerated very fast in 3rd gear and revved it way past 4000rpm even touching 5000rpm. (I never usually drive like this, I am a steady driver really, a plodder). After reaching the 5000rpm mark the car suddenly lost power, the management light came on and it entered what I believe to be 'limp mode'. From then on I could not get the engine above 2600 rpm. Upon reaching my destination I turned of the engine and went about my business. When I returned to start the car around 10 minutes later it started fine. The management light didn't even come on and the car was able to perform as it should. Most, if not all the rattle had disappeared and the car is now able to pull as it should. Lots of pulling power, even in 4th and 5 gears.
So, WHATS THAT ALL ABOUT?
Could the source of the problem be a faulty sensor?
Any help or ideas would be very much appreciated
Many Thanks
