Sudden Loss of Power !!!
 

I drive a Jaguar X type and something strange happened yesterday.
I was turning right into a junction and dropped speed accordingly but then when I tried to accelerate there was a sudden loss of power. I dropped down into 2nd gear with no improvement and as I then was going uphill I was forced to drop into 1st gear and the maximum speed I could get was 20mph. The rev counter was showing revs up to 6/7 thousand when I put my foot down but there was no increase in speed.
I pull over and turned off the engine at which point I noticed that the fan appeared to be running fast and not stopping.
I turned the ignition on and off again and the fan stopped.
I started up again and all power was resumed as normal!
Does anyone have any ideas as to what might have caused this?
Regards

Vikingdon

Can anyone please help with this ?

Don, what I would recommend you do is to have your battery checked by having a load test done to it. You may find that if the battery is starting to get weak, it will allow voltage fluctuations to occur, which messes up the ECU and it will cause it to drop into a "safe mode" and it will significantly drop the power. Then, when you turn off the car and restart it, the ECU is reset and it goes back to normal.

Thanks for replying Thermo !

I will get the battery checked on Friday.

Vikingdon

I had my battery load tested this morning and was told it was perfect!

So has anyone any other ideas as to what is wrong?

Regards

Vikingdon

The problem appears to have been solved !!!

For the benefit of others it seems that the cause was a faulty temperature sensor on the cylinder head. The sensor was incorrectly sending a message to the ECU that the cylinder head was overheating and activating the fan even though the water temperature guage was normal. The car was then put into Limp mode which reset if I turned off the ignition until it gave an incorrect reading once more.

The sensor has now bean replaced and I have not had the problem since.

Here's hoping that is the end of it !

Regards

Vikingdon