Evening all,


Apologies if this has been answered already - I did do a search for flatspots but most results looked to be tyre related.


My X type runs very well, except for a flat-spot when holding around 1600-1700rpm. I can accelerate through this small band and all is then well.


A bit of searching seems to mention the EGR valve. I think this is the one at the top-rear of the engine? I did wonder about using a blanking plate, as it seems that this improves engine breathing anyway. The only thing is there are two types (with and without hole) and I'm not sure which one I would need as I don't know what type of EGR valve I have.


I tried my code-reader plug and it doesn't seem to be logging any faults.


Any thoughts? Am I on the right track with this one?


Cheers in advance,
Daz

 

I think I should have put this in the proper section - can a mod move it if needed. Cheers.

 

You may have a bad throttle position sensor. If the car spends a lot of time in the RPM range you stated, it is possible the sensor has worn out in that one spot. Below and above the worn spot all is well, when it's right there at the worn spot the ECM loses the input and thinks you took your foot off the throttle and reduces the fuel accordingly. This will NOT post a trouble code since a far as the ECM is concerned the sensor is there and working.

The good news is that it's easy for any mechanic to check by looking at either the input to the CPU via the scan tool, or using a volt/ohm meter and checking the component directly.

I would be very hesitant to use a blanking plate for the EGR, it could cause more problems than it will solve. Best to do a proper fix.

Just my first thoughts on the problem. As with anything, it's devilish hard to diagnose something over the 'net without being there to see the car.

 

Good idea about the position sensor Ozzlefinch. I've just tried my Bluetooth diagnostic plug and the torque android app to check it, but the refresh rate on the display isn't really quick enough to show any brief trouble-spots. I'll get some batteries in my analogue multimeter and see if that shows anything up.
Cheers.
Daz

 

Ozzlefinch is correct, on both counts. I would go one further and just get a new TPS. If your car is high mileage the TPS will probably fail sooner than later. They do not cost that much, especially if you get one from a quality company like Standard ignition. Blocking off the EGR is always a bad thing. It does nothing negative to the running of the car, and actually helps combustion......Be cool....Mike

 

As this site is mainly USA based and diesel X Types were never sold there, experience of the oddities of the X Type EGR is not widespread.

If you also post here:

X-Type

you'll find huge numbers of diesel X Type owners with great specialist knowledge, particularly with respect to to blanking and partial blanking of the notorious EGR!

 

Cheers guys, appreciate the feedback.
Mike, that x-type looks very nice in white - don't see that very often!
Daz