I am driving along in my 1998 XK8 with 98K on the clock thinking all is well and bragging to my passenger on how quiet and smooth it runs. Suddenly it felt like I had a flat tire, no place to pull off freeway until about a mile. I started go really slow when I realized that it was the engine and not a tire, & pulled off to a safe place. Turned engine off as it was dying, and restarted. It was really hard to start and sounded awful. The sound is hard to describe, a bit like a blown manifold or head gasket but ran as if one side was out of time. I have recently had the secondary tensioners replaced with metal ones. No check engine light, nothing at all. From that poor description can anyone throw a light on it.The car is still parked and I will pick it up by trailer tomorrow. Someone suggested that it could be the variable cam shaft. I have no experience with 4.0 V8 so I'm not sure if this a job for me or the Indy. I have rebuilt Jag six's in the past and this may well be an expensive fix and I may be forced to do it myself. ANY HELP WOULD REALLY, REALLY BE APPRECIATED.

 

Check for pending OBDII codes, which might not have set the check engine light yet.

Also perform a fuel pressure check. There is a Schrader valve on the fuel injection manifold.

Don't assume the worst until the basics are fully checked out.

 

I will get the code checked on my way home. Wouldn't the engine acted starved if it was fuel pressure, I will check any and everything anybody suggest. Thanks for your help White XKR

 

It is tough to envision the sound from a description. Perhaps if you post a video it would be helpful.


If you are describing more of a banging sound shine a light on the belt tensioner and see if it is snapping back and forth. It could be one of the rotating accessories or idlers has a failed bearing and the belt tensioner is snapping back and forth.

 

Only code, low RPM still think it's a timing issue, chain, variable camshaft unit, don't know. I will pull the cam covers and see if anything is loose or broken. Will not run long enough to record sounds