SEE PAGE 2 FOR VIDEO

Hmm... noticed this the other day - thought it was the seized brake caliper (now changed).

At 30 mph in "D" on very light throttle the revs rise and fall by about 100 rpm. Seems to do it on the flat at about 30mph or going down hill (which is at idle). At 30mph it can give a slight rocking back and forth motion.

At higher speeds it does not seem to do it. Also seems ok at lower speeds.

Anything simple I can check?

Its had a new gearbox about 12 months ago. So I would hope its not that.

Could it maybe be another stuck brake caliper?
Perhaps the throttle pot or some other sensor?

Does it (4.4) have an idle control valve or something else?



Last edited by red_slr on 5th Nov 2010 1:30pm. Edited 1 time in total

Might be worth checking for a binding handbrake.... Land Rover Addict
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Back wheels off and take the adjuster back a few clicks? Or is it best to take the disc off and have a look?

Warped disc?

I'd have thought that a handbrake binding to that degree would be dedectable by a warm rear hub after a few miles.

If a disc is warped, you should feel the brake pedal pulse if you apply the brakes lightly.

Ah, well as the OS brake caliper has been stuck on then I guess that could have warped the disc..

For what it costs might be worth putting a new set of discs and pads on?

The rear discs have quite a bit of rust on them too.. about 1/2 inch of rust on the face of the disc??

Well just been for a drive, the car was fine for the first 5-10 mins. After a few reasonable speed stops I started to get quite a bad judder (in the whole car) and then it started to "hunt" the revs.

The issue seemed to go away after a few miles of gentle driving.

Had a feel of all the brakes and TBH they did not feel that hot. The rear N/S is maybe getting towards being too hot to touch but the rest were ok.

I think as a precuation I might just have to bite the bullet and change all 4 discs and pads. See if that helps.

If not I think it might be a gearbox issue???

Also, just to clarify what its doing.

Under more than 10-20% throttle load its fine. So up hills, general driving.

Under light throttle <10% at lower speeds you can feel the revs drop. Almost as though its going into fuel cut mode?

So if you drive along and you are doing say 1500rpm and you take your foot of the gas then the engine speed drops to idle (500ish rpm? maybe a tad less). Then, when you touch the throttle again the revs go back upto 1500rpm. That is normal right?

Well, its almost as though its about to cut, starts to drop, then rises back up again. At times the revs might fall by 200rpm then jump back up, but most of the time its a very minor drop 100rpm or so then it goes back up. The irritating thing is it only does it at gentle throttle, which is most of the time!

Again, it only seems to do it once warm...

Any advice is welcome before I spend £££ on brakes!?

switch off everything when you take it out next, to rule out aux driven things (i.e. a/c compressor etc) Land Rover Addict
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I will give that a go thanks.

Also check the air suspension compressor/ suspension units - you may have an air leak that is causing that compressor to cut in a lot. 2018 Mini Countryman Cooper S E All4 PHEV in Melting Silver - it’s whisper quiet in EV and polluter modes

Fairly sure its not the compressor but will check. Seems work fine (touch wood).

I am just putting a video onto youtube now showing the problem.

Tried a quick drive with the AC off, still did it.
Again, drove fine for the first 5 mins, then when upto temp it started to hunt.
Full set of brakes on order for Tuesday - so will see if that makes any difference. The rears need doing anyway, and if the fronts turn out ok then I can just keep them as spares.

Here is the video

The first 20 seconds or so are not much to look at.. sorry.

Speed is 29/30 mph and as you can see it bounces up a couple of hundred rpm.

I have spent all afternoon looking on the internet about this issue.

The best post I can find is this one

http://rangerovers.net/forum/viewtopic.php...p;start=30

This is the same issue that I have.

Sadly, after 3 pages there is no fix. There are several reports of people with the same issue.
Some say its EGR...
Others say its just "normal".

Confused now!!

Could it be a faulty MAF or a fault in the wiring to the MAF?