Rumble/Hum at Idle

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

The "D" vibration has been covered extensively. My vibrating sounds, was coming from the roof rack. Some said take it off. For me the vibration sound is like a check engine light. It says time for a tune-up.

Vibration and shake at Idle

Having everything to factory spec is good starting point. 44K through a tank of gas, then doing a minor ture is next step. This includes a clean working PCV and all vacuum leaks repaired.

After trying about everything I found the "Key".
Key is a little bit of "advisive the FSM" gives before disconnecting & spray cleaning the MAF sensor which is part of minor tune.
KEY: "Disconnect battery" which is first step in a minor tune.
Don't reconnect battery for 30 minutes, this reset the ECU. Make sure too clean and grease battery post & clamp before reconnecting.
 
Last edited:
Yes it really is that annoying.

It's probably also the fact that I can't concede to the wife that our mid travel beat to hell 3rd gen 4runner was a quieter vehicle than the mall crawler 100 series we replaced it with.
 
I got rid of mine, not sure how because I wasn’t trying to cure it. But somewhere along the way it has gone, I just couldn’t tell you what I did exactly. Just one day I noticed it wasn’t there any more, I usually pop it into neutral when stopped, It is a habit.
 
Honestly if it was just the hum I could ignore it. Occasionally though it hits just the right frequency where something in the roof towards the rear starts loudly rattling. Its not the roof rack but something inside the ceiling. Drives a fella nuts.

I still need to run through some of those TSB items and probably replace motor mounts (I'm at 240k miles) so it's not like I've exhausted all options just yet.
 
Only use genuine Motor Mounts, aftermarket seems to be to rigid. Changing mine was in the top 3 of improvements I had done, they where only on 170,000 at the time. Seriously only 170,000. take note Range Rover owners.
 
Captramrod01 said:
Honestly if it was just the hum I could ignore it. Occasionally though it hits just the right frequency where something in the roof towards the rear starts loudly rattling.
Click to expand...
Same here, but I've got something rattling behind the dash. Lately I've been switching to neutral when at a red line or drive through. I'm not sure what's easier, replacing motor mounts or digging through the dash.
 
I found the Motor Mounts pretty easy to be honest, I was surprised. The one at the transmission is very simple, I took the trims off from behind the wheels for the front ones and I had no drama.
 
I changed all rubber on the truck when I first had it other than the body mounts and surprisingly the steering rack. I bought the rack ones but they where good, so preferred to keep it rubber, as at the time only Poly was available. The only ones that made any noticeable difference was the rear control arms and motor mounts.
 
Julian Stead said:
I found the Motor Mounts pretty easy to be honest, I was surprised. The one at the transmission is very simple, I took the trims off from behind the wheels for the front ones and I had no drama.
Click to expand...
Hey Julian,

Any other "pro" tips for swapping the motor mounts?
 
To be honest it was so long ago I can’t fully remember, all I will add is to use a good quality trolley jack and a solid peace of timber to jack up the motor. I didn’t plan this good enough and didn’t have the height to release the Mounts, lucky I could drop the AHC to low and then this allowed me to just do it. I attacked it from below and the sides, I can remember only using combination wrenches but I had to add a bit of leverage with a extra wrench as the Nuts where very tight. Once they broke free they unwound by hand so that helped. Mine is RHD so it might or will be different to yours if the steering shaft gets in the way. I can remember for the top nuts I placed a short combination wrench on the nut from the top of the engine bay, then put a long wrench in through the side and over the short wrench so I could crack the nut from behind the wheel. All this was done in the street in less than a hour for the front mounts.

Lucky for me I do have good quality wrenches, I needed a wrench where the ring end had a angle to allow me to get to them and add leverage.. I use Snap On wrenches and not sure of the design of other brands.

I would plan it first and make sure your happy that you can get to the nuts with the tools you have, I didn’t strip anything off other than the trims in the wheel tubs and the sump guards, so a bit of trial and error can be done first as you don’t immobilise the truck in anyway to gain access.

Don’t put your fingers in harms way, use pliers or similar to pull the mount out and back in.
 
I was able to access my drivers side motor mount from under the truck very easily. Haven’t tried to get to the passenger one but I suspect through the wheel well would be a decent choice like Juilian said.
 
Julian Stead said:
To be honest it was so long ago I can’t fully remember, all I will add is to use a good quality trolley jack and a solid peace of timber to jack up the motor. I didn’t plan this good enough and didn’t have the height to release the Mounts, lucky I could drop the AHC to low and then this allowed me to just do it. I attacked it from below and the sides, I can remember only using combination wrenches but I had to add a bit of leverage with a extra wrench as the Nuts where very tight. Once they broke free they unwound by hand so that helped. Mine is RHD so it might or will be different to yours if the steering shaft gets in the way. I can remember for the top nuts I placed a short combination wrench on the nut from the top of the engine bay, then put a long wrench in through the side and over the short wrench so I could crack the nut from behind the wheel. All this was done in the street in less than a hour for the front mounts.

Lucky for me I do have good quality wrenches, I needed a wrench where the ring end had a angle to allow me to get to them and add leverage.. I use Snap On wrenches and not sure of the design of other brands.

I would plan it first and make sure your happy that you can get to the nuts with the tools you have, I didn’t strip anything off other than the trims in the wheel tubs and the sump guards, so a bit of trial and error can be done first as you don’t immobilise the truck in anyway to gain access.

Don’t put your fingers in harms way, use pliers or similar to pull the mount out and back in.
Click to expand...
What performance or comfort difference could you feel?
 
Now this one is a bit harder to explain. It basically made the truck feel more solid and settled. A bit like the rear control arms, I didn’t realise that there was really a issue, but after replacing them, the truck felt more composed. It was noticeable.

My Motor Mounts where worn though, you cannot tell really until they are off. The rubber was separating from the metal plates, so this obviously gave movement on the road. You can drop your transmission cross member in 5 to 10 minutes to inspect the rear mount, this might give you the best indication to the condition of the front ones. I wish I had taken side by side pictures of old to new but I get blinkered when I work and forget.
 
Julian Stead said:
Now this one is a bit harder to explain. It basically made the truck feel more solid and settled. A bit like the rear control arms, I didn’t realise that there was really a issue, but after replacing them, the truck felt more composed. It was noticeable.

My Motor Mounts where worn though, you cannot tell really until they are off. The rubber was separating from the metal plates, so this obviously gave movement on the road. You can drop your transmission cross member in 5 to 10 minutes to inspect the rear mount, this might give you the best indication to the condition of the front ones. I wish I had taken side by side pictures of old to new but I get blinkered when I work and forget.
Click to expand...
I usually look at engine for movement while under a load. If remarkable engine movement noted, I then watch mounts while under a load. It's been very subjective, not have brand new to compare with. Did you happen to do this before replacing, if so what did you observer??
 
I didn’t check them before hand, I just bought them and installed them as part of a refresh. I think I tried prying on the rear one before but nothing alarming found. I just think near 20 years and 170k must take its toll on rubber, so changed everything. I changed everything with OEM, I done it fairly quickly after purchase and over 3 weekends to change the lot, so I can’t remember the exact details. But overall the ride was improved dramatically. I changed complete suspension components and not just the bushes. Somewhere along the line the D vibration has disappeared.
 
I have also addressed the dash board by applying some furry tape from velcro to contact areas and also taped it around some of the looms and connectors to stop any vibrations. I defiantly took pictures of this and posted them on here somewhere. I also used fabric ties around the dash and center console areas to help reduce noise.
 
I had a low hum at idle when the AC was off. The LX470 had 202k on the odometer. After changing the spark plugs it was gone.
 
You must log in or register to reply here.

Share this page

Back
Top Bottom