Intermittent rough idle

[CMGRover]

My LR3 has an intermittent rough idle. When I first start it and it settles into the "normal range" it goes from like 700 down to below 500 and then goes back up, sometimes pretty roughly. Put it in drive and it evens out. Then after driving it for a bit (half hour or more) it usually idles just fine in park or drive. I have 130k on it, V8. No codes.

Thanks

 

[roverman]

When is the last time you cleaned the throttle plate and MAF?

 

[uoflcardfan77]

My thoughts exactly. Throttle body cleaning and if that doesn't do it then the MAF.

 

[Houm_WA]

Since it only happens when it's cold, I'd look at the thermostat too AFTER those two suggestions above.

 

[CMGRover]

It doesn't only happen when it's cold...like if I drive it and fully warm it up, it's fine, shut it down and restart it (engine still warm) it'll idle rough.

MAF sensor is a year old, no more than 15k on it. I haven't cleaned the throttle body. I'll try that.

 

[roverman]

I was amazed just how instantly cleaning the throttle body worked, it was dirty but I didn't think it was THAT dirty. I'm 95% confident that's your problem. It's not hard to do, but I did find and follow a pretty good video on youtube just to make sure I didn't screw anything up.

 

[CMGRover]

Anything in particular I need to know about the LR3 throttle body since it's drive by wire? Or is it safe to open up the butterfly valve to clean it?

 

[CMGRover]

Thanks so much guys, did the throttle body cleaning and damn it hasn't idled this nice in years. Thanks so much, I have my LR3 back lol.

 

[roverman]

Crazy isn't it? Happy or you, nice work!