Newbie here in need of some remote diagnostics.

s-type 2.7d 2007

From cold, starts and runs fine for 5-10 mins then restricted performance kicks in….no smoke, just the loss of acceleration and power.
same every morning…fine, then not fine.

There seems to be a million different reasons for restricted performance…. Anyway of narrowing it down without throwing the parts catalogue at it?

new fuel filter didn’t sort it.

TIA

 

Just read the trouble codes by OBD2 reader. If you don´t own one, pretty much any mechanic shop have for sure and will read the codes for low money.

 

should have mentioned - no codes🙁

 

No codes.. huh..
Hmm.. The fuel added are calculated by measured airflow by MAF sensor(s). These (2pcs) are right next to the airfilter box. There are spray solvent meant for cleaning MAF sensors. (do not touch the thin wires inside of the duct, they are fragile) During cleaning you can try to swap places of the two sensors. Upper one are for secondary (+2800rpm) and lower for primary.
This are pretty much only issue what i can think without codes...

 

Hi So Good,

Very sorry to hear of the issues you are having with your XF. I can only agree that you need to check the fault codes to make sure nothing is amiss there. I know its been said before many times but these diesels really need a really good long work out which in depending where you are is not always easy. I only use my 2008 XF for long distance cruising and that can be anywhere from a 400km to 500km day drive to in my case several thousanfs of KM. Never had any restricted performance warning messages ever.

The other thing would be to get it checked over by an independent Jaguar service garage (not the JLR dealership). I have an independent Jaguar servicing guy who keeps my car in excellent condition. I know none of that is technical advice but if a check shows there's nothing serious take it for the drive of its life.

 

From the sounds of it it is your EGR Valves that are failing. The EGRs (you have 2) are not meant to work when the car is cold or when the engine is not under load, so down hills or parked they're not needed, and I dont think they kick in until about 2,500 RPM. The reason you are getting the restricted performance is probably because the EGR Sensor A ( the MAP Sensor) is telling the engine that the EGR is already being used too much, you will probably get no fault codes on most basic fault code reader, more in depth OBD readers will see an issue, but in most cases will say its you map sensor.

Map Sensors are about £109 from Jaguar UK Dealers, or second hand from about £35- Cleaning the EGR and changing the MAP will work for about a week then the problem will slowly start again.
Jaguar EGR's are about £400 to £600 per pair from the dealer (you can buy singularly). You can get a pair on Ebay for just £70 if you're on a budget, it takes 2 hours to change each bank if you dont have fat hands or short arms

You can clean your Map Sensor but use suction- DO NOT POKE ANYTHING IN THE LITTLE HOLE! If you push debris in there it will fail and fail withing hours, most probably on a Sunday

Do you have any auto club or road side recovery membership? I drive out to the park when I have an issue I cant find the cause of and call them out to come diagnose the problem for me whilst I drink coffee and eat cake in the sunshine, its free (not the coffee & cake) if your have membership. I think you have AAA in the states, we have RAC, AA and Green Flag here in the UK. Their readers will read any ECU in the car and will tell you about any electrical issues you might have.