auto kick down vers tappet noise ?

[browneee]

Ok, I've got a 94 XJ sport ...

Now every time I put the engine underload (overtaking, accellerating uphill etc) the tappet noise become audible when in "drive". If I drop it down a gear into "3" it goes away. Now I've gone through my service manual and it reconmends checking the "kickdown", which I did and followed the adjustment method...

Have any of you made these adjustments &/or cured this problem ?

[langer1]

Ok, I've got a 94 XJ sport ...

Now every time I put the engine underload (overtaking, accellerating uphill etc) the tappet noise become audible when in "drive". If I drop it down a gear into "3" it goes away. Now I've gone through my service manual and it reconmends checking the "kickdown", which I did and followed the adjustment method...

Have any of you made these adjustments &/or cured this problem ?
That don't sound like tappet noise, that sounds like detonation or spark knock.
Try better fuel and pull your engine codes, one of your sensors is off causing a lean air/fuel mixture.

[browneee]

well i checked the code's... "55" which indicated "normal" and end of check ?... Any other thoughts ?

[DeadEyeJ]

Spark knock, ping, predetonation are all the same thing. They are caused by a too-advanced spark, a lean fuel mixture, or too low an octane rating for your fuel. It typically shows up a mid-RPM under load, such as while climbing a long hill. In my experience, most engines will ping a little under these conditions. A little ping is harmless, but heavy pinging can be dangerous to an engine. Higher octane fuel would be the first route I would take to solve the problem. If that doesn't do it, start checking sensors.

Jared:patriot:

[Oatmeal]

I would check your knock sensor. Modern computer controled engines like yours shouldn't have any detonation (never a good thing) issues. It's basically just a microphone that'll pick up the "pinging" and tell the computer to make timing and/or fuel adjustments...........Hans

[langer1]

I would check your knock sensor. Modern computer controled engines like yours shouldn't have any detonation (never a good thing) issues. It's basically just a microphone that'll pick up the "pinging" and tell the computer to make timing and/or fuel adjustments...........Hans
What year did they quit using knock sensors? The newer ones don't have one.

[old_man]

Renix had them, HO didn't.

[Oatmeal]

What year did they quit using knock sensors? The newer ones don't have one.Ok, I stand corrected. After further research I found that '90 ('91 being the introduction of the H.O.) was the last year for knock sensors. I'm still learning about these things (just bought a '96) so, have patience with me.........Hans