Hello to everybody,

I have a big question as the subject of the topic.

If an engine 4.0 of an XK8 is probably cracked down cause chain tensioner, so when you turn on the key the engine not start, the check engine light should be ON or not ?

tanx a lot for your thoughts about it.

 

I would think that the cam position sensor would set a check engine light if one of the cams was out of synch with the crank. There would also be a misfire code from the cylinders with no compression if the valves were bent. I imagine there would be others as well.....so yes, there would be a check engine light.

 

Not necessarily... most detected issues require a number of 'fails' to occur before the software allows a failure to be displayed. This eliminates a lot of false positives causing owner concerns and warranty expense for the OEM. By the time a code has been displayed for a cam being out of sync with the crankshaft the engine will probably have displayed its own mechanical 'notification' (banging, hole in block, refusal to start/run, etc.)

 

Tanx for the answers, but in my mind I think that it is "impossible" that neither one check light not only the engine light, but neither others are ON when i turn on th key all are ON for the usual global check, then all get OFF.

The engine don't start this is the problem, and very very quickly just open the boot engine a jag dealer mechanic said to me that it is the engine gone probably for the chain tensioner.

I never heard any classical noise tik from the engine before this happen.

 

Check this out:
https://www.jaguarforums.com/forum/g...d-first-30792/

and also

Cylinder Wash - is this your problem? Did you run your engine for just few seconds or a minute, and now it won't start?

Quote:
Originally Posted by steve11
The 1997 to 1999s had a serious problem with this exacerbated by fact that the cold start fuel cell algorithm was programmed overly rich.

First, you have to make sure that the battery is charged up so it doesn't die in this process. Next, try to start the car with the accelerator pedal held to the floor. Do short 20/30 second tries, letting the starter rest 30 seconds in between and continuing to hold the pedal to the floor.

Holding the accelerator fully opened shuts off the fuel delivery so you don't continue to wash oil from the cylinders which destroys compression.
It should eventually start (maybe 4/5 tries). This is a factory approved method for cylinder wash, a well known and documented condition.

There are (actually) two processes used to revive an AJ26 from cylinder wash, one factory approved and one developed by the shade tree mechanics. The proper way is to hold the gas pedal to the floor which shuts off the fuel, then cranking in small increments until cylinders dry out and compression is restored and the engine will eventually fire. The improper way involves removing the spark plugs, adding oil to each cylinder reinstalling the plugs then hoping for a start, but this method can have detrimental effects on the cats from the unburned oil pushed into the cats.

AJ26s had a poorly programmed cold start fuel cell algorithm when under certain conditions, would overflood the cylinders with too much fuel. This caused the oil to be washed off the cylinder walls and caused a temporary loss of compression. Without the oil coating the engine would not start, but fuel would continue to be injected into cylinders making the situation worse. Jaguar never fixed the problem in the AJ26s, but by the time the AJ27 came out the ECM had a corrected cold start program. Cylinder wash occurs when the AJ26 is cold started then shut off before the engine warms up.

Any time an AJ26 cranks but doesn't start, this is the first and easiest process to perform. It will save a lot of wasted time chasing fuel or ignition problems that very seldom are the cause. In my shop I see this condition several times a year - customer calls which I describe the restart procedure over the phone.

 

Tanx a lot for the guide, but I must explain how it happend.

First I have an AJ27 engine, november 1999.

I was in highway at about 130 km/h (80 mph) Suddenly the car was sobbing, the hand of the oil rise to maximum, and then the car turned off and luckily there were not many other cars and so I was able to park in the emergency lane and call the tow truck

with the tow truck we headed over to the dealership jaguar 'nearby, and the mechanic has not entered a tester has only opened the bonnet has tried to turn the key a few times, checked the engine oil (which was perfect ) and saw that the car would not start the engine it was ruled that time because of the failure of the supply chain

He told me that to change the engine will cost 9.000 euros.

For this I am asking why if I have the engine blowed the chek engine will not light on but all lights turn off after the check.