I just recently purchased a '98 XJ8. It has the "Restricted Performance" message come on when you try to turn the engine on. When I turn the key I get absolutely no sounds coming from the engine compartment. I am believing after doing some research online that it has probably suffered from the faulty timing belt tensioners and probably jumped timing. As a result unfortunately the engine may be seized and that is why I am hearing absolutely nothing when I try and start the engine. Does anyone have any thoughts as far as diagnosing what can be wrong. I have an OBD II code scanner and tried clearing the restricted performance code from the memory but to no avail. Does anyone know how to remove the code apart from taking it to the dealership to be cleared? Any thoughts or advice would be appreciated.

 

It is turning over? What codes do you have?

 

It is not turning over. I can only hear a humming sound coming from the dashboard. I do not hear the starter trying to make any sound at all. The codes that I have pulled do not give me any information as to why it will not turn over. I am getting a P0327 Knock Sensor 1 Circuit and a P1000 OBD Systems Readiness Test not complete. Any thoughts?

 

Might I suggest removing the camshaft covers, turning the engine by hand (after removing the spark plugs) and see if the camshafts line up? It will take all of 15 minutes to do so and will answer alot of questions.

 

I would do basic stuff before taking the camshaft covers off (though you should do it to check the secondary chain tensioners, there are many threads about them and they should most definitely be replaced before your engine turns into a brick).

The humming sound is somewhat normal... My Jag does it if you turn it to "on" without it running.... I *believe* it is throttle body making that sound.....

The fact that the starter isn't moving is the 1st thing I would trouble shoot.....have you tried jumping it? Charging the battery? Perhaps the starter is fried?

The knock sensor is a problem..... the p1000 isn't - other than it means the codes were probably recently cleared. The knock sensor could be a bad connector or melted wire or just a bad sensor etc... but I am pretty sure the engine should crank even with this error.

 

Also, if you suspect a seized engine you can take a long socket/wrench and put it on the crank bolt and see if it turns (with the key out of the ignition of course).

 

Even if the engine was seized, you'd hear the starter bendix engage and try to turn the engine over...

I suspect it is something other than tensioner and seizure - much more likely electrical.

Certainly do what Ron suggests to verify that the engine will turn over - I suspect you will find that it does. This then leads back to electrical.

 

The easiest thing to check is the large battery + cable connector stud on the 'false bulkhead'.
It is the big wire to the starter and Alt. It has a bad habit of MELTING the insulators because the terminals get loose and overheat. Go to the passenger side of the engine compartment and pull the plastic cover from the control module housing assy. You will see both sides of the terminal stud. If that is OK, then remove the 4 TORX screws from the ECM/TCM housing to get to the starter relay. It should be the second one from the engine. Pull the relay and remove the brown plastic cover. Look at the contacts. Are they BURNT??????? You can swap with another relay to see if the engine cranks. You can also put a jumper wire from 30 to 87 to check for starter operation or manually close the contacts on the relay.

I have seen these fault many times. It is the fastest way to check the starter. The next thing is the starter itself which will require getting under the car.

let us know what you find.

bob gauff