ok, firstly i have had a good read from the threads about this 'problem' on here but i must be a bit dim.

my son-in-law bought this car recently and the seller said he had used it for a few months (his father owned it but died) and then had a fair amount of work done on it. it ran ok for about 3 months then started to be 'jerky' when driving and the engine management light along with the usual 'cruise control unavailable' occasionally dispayed - so we knew all was not well.

we are now at the point where it starts and runs sweetly but wont move 'cos as soon as you select a gear you get the messagethe message.

as far as i can see this car has sensors all over it and yet when we checked the bus for a fault code (using a £5k+ unit we borrowed not an ebay cheapy) there were no fault codes to display.

i know the message is generic so the fault could be virtually anything but since there are no fault codes does this mean its something that has no sensor? i am assuming this is the case as i guess even if its the usual o rings leaking they must have a sensor somewhere which would cause a code.

any suggestions please?

 

Hey BlackEagleS. To me it sounds like one (or both) of your knock sensors are going bad. When your engine gets out of sync from faulty knock sensors the computer doesn't think your cruise control will be able to maintain a set speed so it disables it and shows you that message. You didn't say anything about a check engine light though and these sensors can throw a fault code, but I think if the problem goes unattended a fault code will come up. I can't remember the code for this specific problem off the top of my head, but know it does take quite a bit of labor to even inspect these two sensors because you must take the top of the engine apart. For that reason you may want to wait for the sensor to throw a fault code so that you can know for sure that this is the problem opposed to just going in the blind and possibly being wrong. Hope this helped!

 

This was the culprit for me when I got the message. Worth a check.

https://www.jaguarforums.com/forum/x...culprit-75411/

 

Post #2, no sorry no way
post #3 wow very isolated and can be a brake switch.
2 things, 99 times out of a 100 the cruise unavailable is caused by a vacuum leak on the engine. And since you mentioned running roughly, i say youre also 1 of the 99. Replace rather than jacking with "trying" to isolate to one leak. I would since your car is 10 yrs old. Replace the imt orings, pcv hose with updated ribbed one, heat shrink sleeve the check valve or replace the brake booster pipe. And replace the upper and lower intake orings(all 12) these are your biggest issues on this car. For more info, pics etc search p0171, p0174 or i believe its also in the diy, faq section of the xtype forum here

 

thanks, i will pass these suggestions on to him.

i still dont see how the management system can know there is a fault unless a sensor tells it and so there must be a fault code generated but ther isnt. rather than using this fault code reader, i dont suppose (like some other cars) there is a combination of buttons/pedals you press and the codes are displayed on the dashboard?

 

Brutal, the exact problem just happened to my car. I fixed it last week.

 

Check your wiring harness going to the throttle body. I had one wire break loose (yellow) and the engine ran, but caused other problems without throwing a code. Also, have your battery checked for amperage, not just volts. Don’t overlook the battery.

If these are OK, then it’s the grocery list of things to change out. Just like Brutal stated.

1 – PCV hose – Make sure you have the ribbed one installed
2 - Check the rubber boot from the air filter box to the throttle body for any holes or cracks.
3 – Check for any Vacuum leaks – Listen or spray with WD-40 misting while listening for the engine to change RPM
4 – Intake gaskets and the ones below the fuel rail. 12 total.
5 – IMT Valve gaskets
6 – PCV
7 – Remove the throttle body and give it a through cleaning. Watch out for the coolant when you pull the 2 rubber hoses off.
8 – MAF Sensor – Change if the above are changed out and you get “Engine Lean on Bank 1” and “Engine Lean on Bank 2”
9 – MAP Sensor

Senior Members - Please correct me, if there is something stated wrong or omitted. I’ve just finished replacing all of the items listed above except #1 and #9. Had #1 on the engine and I hope #9 isn’t needed.

 

ok, thanks.

im not sure what this pvc hose is that has been mentioned.

if im looking for an air sucking noise then having had another check with a short length of hose in one ear and run the other over the engine to amplify any noise i find a 'sucking' comming from the connection of what i can only describe as a plactic union bolted/screwed to the right hand side on the engine which has a (about) 1" hose, which is just a push fit, comming from it and over the top of the engine. im guessing its something to do with engine/crankcase emmissions but the hose does not have any clip marks so i guess it does not need one - but i sure makes a 'sucking' noise.

sorry, but i cant find a diagramme/picture of the engine so had to try to describe it - badly!!

 

The PCV hose that needs to be on the car is the ribbed one. It comes from the PCV located on the valve cover to the manifold. Also, you need to have clamps on both ends. There's two pictures - ribbed and non-ribbed. The non-ribbed one will be sucked closed due to the vacuum pressure.

 

ok, checked it and there was a small split so changed it - one less thing to check again - but still the ehgine runs but thats all.

 

i should also add that i sprayed 'easy start' over everything else and the engine did not 'rev up' so i will assume the others usual suspects are air tight, but see

https://www.jaguarforums.com/forum/x...des-etm-81054/

 

Am i missing something here, or have we yet to find out whether this car is a manual or automatic - might be relevant?!

What I would like to know is

Auto or Manual?
Any dash warning lights on and when?
Does the engine stall on selecting a gear or is there just no drive?
If a manual, how's the clutch behaving?
If an auto, do any of the lights on the J Gate light up as the lever is moved?
Was the £5k scanner Jaguar capable? I just feel there must be some useful codes hidden in there somewhere! (But not in the dashboard diagnostic system!)

 

Did you pull any engine codes?

 

things have moved on a bit allbeit ive got nowhere - please see https://www.jaguarforums.com/forum/x...des-etm-81054/