Hi,

Sometimes, when moving in low speeds (20-40 km/h (25 mph)), RPM drops to low levels and car sort of twitch for one time or another, so I just hit accelerator and issue disappears.

Today, I have started the car, let it warm up for 10-15 minutes and when tried to move, engine stalled. When tried to start again, there were no sound at all when turning ignition key. After 4-5 tries, it finally started.

I have previously bought sensor crankshaft and mechanic changed it today, as old one had some sort of mechanical sag. I thought this was the issue. However, upon driving home (engine was warm), rpm dropped again. Car starts fine now, by the way.

Any ideas on what could be wrong? Is this a sign of engine breakdown?

Daimler V8 Super 1999 with Nikasil engine.

 

Perhaps the transmission is searching for a gear.

 

Is this normal? Would any diagnosis help?

 

Do you have any check engine lights? If not, it's going to be a "hands on" diagnosis.

 

Well, it does not give any warnings, when turning the ignition key on, although check eng light is on (not below speedometer, but in the left side), not sure if this is a default behavior or not, but it goes away after car is started.

Also, I noticed, when when I started car today, it showed me traction control and stability control (or something similar) fail messages for a few seconds.

 

It does not sound like a Nikasil problem. The main symptom of a Nikasil problem is the engine spinning very fast and not starting, or oil blowby out of the crankcase showing up somewhere. Has your car had the throttle body recall done on it ? I believe it was the '98 - '99 that had this issue.

 

Hi,

No, it did not. Are there any quick and easy ways to check, if it does require that?

 

No, unfortunately that is only the gasket for the throttle body. Here is some info on the recall -

http://members.***.net/blackbeard200...le%20body2.pdf

Check and see if your VIN number is within the range. It says '98 and '99 superchanged XJs within the VIN range had this recall. I assume yours is supercharged (SC) since it is a Daimler Super V8. I'm sorry, I do not know if Jaguar dealers will still perform this recall work on your car, but if your VIN falls within the range, it might be worth a try. The throttle body is definitely not a cheap part to buy, somewhere around 1,000 euros. Don't take my word that this is the problem (of course). You might try cleaning the throttle body and see if that helps any.

 

Thanks Jimmy, appreciate your help.

 

Okay, so, I have turned on sport mode, hit gas pedal few times and after resumed to calm driving (tried with both, off and on sport modes), rpm started to go down and it twitched many times.

 

check for codes and explore throttle body issues and mass air flow sensor. Look for vacuum leaks, perhaps clean the MAFS to see if that clears it up.