I’ve noticed that when driving at times, the engine sounds and feels lumpy, although the rev counter stays steady. The car drives with no issues, drives fine, accelerates well and appears to use no more extra fuel. Anyone got any ideas what may need attention?

 

Are you concerned about your XK8 or XJ8?

 

@DougXK8, is the MIL on? If so, post the codes here.

How many kilometres/miles on the vehicle?

Sometimes the AJ26/AJ27 can feel 'lumpy' if there's a failing or fouled spark plug or coil unit.

 

Sorry, I should have said it’s on my XJ8 3.2L. It’s only done 62,500 miles. Have undertaken a diagnostic which has shown nothing. Everything is fine.

 

Can you elaborate just a bit more on this situation? Example: Does it happen more so when the engine is cold, completely warmed up, at idle with the A/C on, driving up a hill, at a certain mph/kph, at a specific rpm or at wide open throttle?

 

Have the primary and secondary timing chains, guides and tensioners been replaced with the latest, metal-bodied versions?

 

I notice the “problem” only when I idling, I.e. when stopped in traffic. When driving, it sounds fine. As stated before, although noticed when idling, the rev counter isn’t showing any increase/decrease in revs. It doesn’t matter if it’s hot or cold on any type of road. The upper timing chain tensioner has been changed to later metal one.

 

First Clean the maf get maf cleaner spray it let dry for while then Install I used carburetor cleaner to be honest it did work way better than the maf cleaner
and check the air intake rubber around the throttle body and see if there's air leaks get the spark plugs out and see if there's cracks if they're not iridium get ngk iridium change air and fuel filter . If these things did not imporve the car condition then it will be time to remove the valve cover check if timing jump

 

Mobile 1: Thanks for that advice. Will do what you have suggested and see if it makes any difference.