vibration at idle - motor mounts?

[jlglr4]

If you’ve got a manifold pressure problem, that’s probably the cause of the slightly rough idle. Could be basically anything that is affecting (increasing or decreasing) the flow of air into the manifold - throttle body, vacuum leak, pressure leak, obstruction (air filters). Some specific things that come to mind are problems with the vacuum brake assist lines/pump (especially if this is the V8,), PCV valve on passenger side or crankcase vent tube on drivers side, purge valve, intake or exhaust manifold leak. Again, I think fuel trims might give some clue at what you are looking for - if manifold pressure is too high, the car will try to add fuel (positive fuel trim). If manifold pressure is too low, the car will try to subtract fuel (negative fuel trim).

 

[ftillier]

PCV valves are on order already with my oil change kit, I figure they've had a good run, no harm in just putting new in at this point. If it's every 13 years I'm OK with that.

 

[Longtrail]

Where did you order them? I'm thinking to do the same while the engine is all stripped own...

 

[ftillier]

I got them from FCPEuro, along with the throttle body gasket and oil/filter.

Land Rover Crankcase Breather Valve Repair Kit - Febi Bilstein LR133579

Land Rover Crankcase Breather Valve Repair Kit - Febi Bilstein LR133579

www.fcpeuro.com

 

[Longtrail]

Thanks, just ordered two! What oil are you using?

 

[ftillier]

I get the Liquimoly 5w20 from FCPEuro too, a 5L and 3x 1L jugs, along with a filter. I don't bother with their kits as they are just a convenience for ordering and I don't need the drain plug since I use an extractor.

 

[Longtrail]

Thanks, was thinking exactly the same, also have a vacuum extractor here... It's going to be part of the current work (by necessity)

 

[mgmavant]

I'm having the same issue with my new to me 2015 lr4 with 114k miles on it. I've cleaned the TB and changed the air filters, and prior work to the truck show a spark plug change about 5k miles ago. No change with, or without the AC compressor running. Slightly worse in reverse than in neutral and drive. Vibration is only noticeable at idle (~600 rpm).

Since I bought the truck I've also changed the oil and changed out the power steering fluid. Thinking about changing the transmission fluid, but haven't gotten to that yet. Doesn't appear to have unusual engine movement when revving, but didn't try it in gear.

 

[16FujiDisco]

I get a vibration at idle too, but only after the rpm’s first come down, then it stops. Is yours lasting the whole time it’s idling?

If I’m in park and blip the throttle, as the rpm’s drop to 600 the is a brief vibration in the overall feel of the truck and slightly in the steering wheel. After a second or two the idle settles at a needle width above 600 and is smooth again. I’ve noticed this since I got it at 50k mi. I figured that 600 rpm is the point just above ‘barely’ running, and when it dips to that point for a second, it’s kinda like off balance.

 

[ftillier]

Mine I can feel when we stop at traffic lights.