Prado 95 Noise at highway speed, Any ideas???

zsandoe

New Member
Joined
Feb 16, 2020
Messages
21
Country Flag
united_states
So I just purchased my prado about a month ago and I have to say, I am already in love with it. Everything is great except for a pesky noise at highway speeds. Here are the details:

The noise seems to start around 60-65 MPH on the highway. Its a loud noticeable bass type vibration or humming noise. It does not sounds like a wheel bearing as its not present when I slow below 60ish. As far as I can tell, it sounds like its coming from the front passenger side of the vehicle. I should mention that there is no change when you put various windows down. The noise is fairly steady as in there is no pulsing or anything like that. Could this be an alignment issue possibly(car tracks straight)? The previous owner didnt drive the car very much over the past few years (only a few hundred miles each year).

Let the ideas fly! I am at a loss on this one...
 

Shayne

Well-Known Member
Guru
Joined
Feb 2, 2013
Messages
13,610
Wind speed related check your radiator cowl or manifold heat shield to see if they are loose .
 

zsandoe

New Member
Joined
Feb 16, 2020
Messages
21
Country Flag
united_states
Wind speed related check your radiator cowl or manifold heat shield to see if they are loose .
Thanks for the idea shayne. I’ll have a look! I don’t feel anything in the steering column so that is a good idea. It does seem to reverberate through the cabin. Would you expect it to be more of a whistle with wind speeds?
 

Shayne

Well-Known Member
Guru
Joined
Feb 2, 2013
Messages
13,610
I've had both , a loose radiator cowl touching the fan only very lightly at high speed actually threatened to make the truck overheat though i can't remember any noise with it .

But that flimsy little heat guard on the manifold made a right racket when i forgot to tighten it after removing it to paint .

When you can almost feel a noise its something to worry about but your description suggests its just sound so something loose flapping about or rattling consistently with your speed seems most probable to me , headlights , bumper , grill , airbox give everything a good shake see what moves .
 
Don't like the adverts?  Click here to remove them

zsandoe

New Member
Joined
Feb 16, 2020
Messages
21
Country Flag
united_states
I've had both , a loose radiator cowl touching the fan only very lightly at high speed actually threatened to make the truck overheat though i can't remember any noise with it .

But that flimsy little heat guard on the manifold made a right racket when i forgot to tighten it after removing it to paint .

When you can almost feel a noise its something to worry about but your description suggests its just sound so something loose flapping about or rattling consistently with your speed seems most probable to me , headlights , bumper , grill , airbox give everything a good shake see what moves .
Will do. If I can’t come up with anything there I’ll give you another shout.
 

Bob

Well-Known Member
Supporter
Joined
Jun 30, 2011
Messages
1,073
Country Flag
ireland
Vibration at speed will always point me in the direction of the UJs on the prop shafts to be checked. If a joint on the front prop was dried out or worn it can resonate at speed. Not a difficult fix either
 

diggerdave

Well-Known Member
Joined
Oct 5, 2014
Messages
541
Tyres with flat spots or gone out of round can have weird effects. Especially likely if the car has been parked up for a while. A basic test is to swap the wheels around and see if the nature of the noise/vibration changes... bit of a faff but it helped with a Trooper I used to have.
 

zsandoe

New Member
Joined
Feb 16, 2020
Messages
21
Country Flag
united_states
Vibration at speed will always point me in the direction of the UJs on the prop shafts to be checked. If a joint on the front prop was dried out or worn it can resonate at speed. Not a difficult fix either
I’ll have a look. I was going to grease them this weekend
 

zsandoe

New Member
Joined
Feb 16, 2020
Messages
21
Country Flag
united_states
Tyres with flat spots or gone out of round can have weird effects. Especially likely if the car has been parked up for a while. A basic test is to swap the wheels around and see if the nature of the noise/vibration changes... bit of a faff but it helped with a Trooper I used to have.
Honestly this isn’t a bad idea and I’ve wondered myself if the issue is in the passenger front tire. Noise seems to radiate from there(as far as I can tell). The tires seem like they are in good shape but the drivers side rear tire is a different brand and style. I did a quick highway run today and it seems if I change lanes fairly aggressively to the left the noise ceases
 

diggerdave

Well-Known Member
Joined
Oct 5, 2014
Messages
541
Out of round tyres or flat spots often aren't visible, so there may not be any obvious indication. That said,

drivers side rear tire is a different brand

I wouldn't be surprised if that's the problem.
 

Bob

Well-Known Member
Supporter
Joined
Jun 30, 2011
Messages
1,073
Country Flag
ireland
Now you mention it diggerdave, I had a hoppy tyre a few years ago, it was only brand new, I bought 4 Bridgestone Duellers (why...I have no idea) before a trip to France, and on the way to the ferry we got vibration.. stopped in a garage and he put the front right on the balancer and you could see it's ovality.. stuck a new one on and made the ferry..
 

Beau

Well-Known Member
Joined
Jan 28, 2011
Messages
2,005
Country Flag
guyana
Also check your airbox lid is tight with the clips. They can resonate through to the inside of the truck if they're loose.
 

outdoordan

Well-Known Member
Supporter
Joined
Dec 5, 2012
Messages
251
Daft question I know but is 4WD engaged? If the light on the dash doesnt come on 4WD wind up can cause otherwise untraceable vibrations.

Would expect it at slightly lower speed though.
 

goodoldboy

Well-Known Member
Joined
Apr 30, 2010
Messages
1,437
the drivers side rear tire is a different brand and style.
It's really important with permanent 4wd that you use matched tyres - same tread pattern/ make & similar tread depth.This is to avoid transmission wind up.
 

chadr

Well-Known Member
Joined
Mar 19, 2010
Messages
2,910
Garage
Country Flag
england
If you're running with diff locks ON, I can understand that but with open diffs surely there would be no wind-up regardless of tyre size etc. Obviously will have a negative impact on handling, braking and safety in general.

Happy to be corrected...

Add : @ OP - I assume the Prado you have( as per profile pic) is a petrol one, presumably with the 3.4 V6 (5VZ-FE) engine? If so, they have a "characteristic" that around 2700-2800rpm the OEM exhaust system can generate a booming noise/vibration. Something to do with a "flap" in the middle silencer or similar. (I've not experienced it personally as I have a stainless custom system). However plenty of posts on the topic if you search Pradopoint (Oz based Prado forum).

Just another thing to check in addition to all the good pointers already provided. :thumbup:
 
Last edited:

goodoldboy

Well-Known Member
Joined
Apr 30, 2010
Messages
1,437
but with open diffs surely there would be no wind-up regardless of tyre size etc.
Correct my friend.But of course it's in low where the problem lies & the damage can be gradual & go un noticed.Even on slippery surfaces tight turns are the problem.
 

frank rabbets

Well-Known Member
Joined
Mar 1, 2010
Messages
4,998
I was also thinking of tyres. I'm pretty sure tracking being off would not create noise or vibration. Sometimes tyres will wear strangely ( known as "castellation"). This causes drumming. Tyre companies have used the word "casellation" to confuse the public when they complain. The companies say they don't know what causes it. Well to me it's premature tyre wear involving crap tyres.

I bought a " fully prepared to Toyotas best standards" 100 from a Toyota stealership in Croydon. Foolishly I trusted them but when I checked the car over, on arriving home, I found 4 different brand tyres on it and a huge hole in the spare together with a host of other faults. They can't even read their own owners manual " All tyres must be of the same brand and specification ". Sorry thread drift.
 

diggerdave

Well-Known Member
Joined
Oct 5, 2014
Messages
541
it's premature tyre wear involving crap tyres

I'm sure that's right.

When I was on a tighter budget a few years back I experimented with remould off-road tyres (one of the better known makes) and bought tyres that were the same pattern on the same style as a well-known branded tyre.

They were great when new, but after a couple of years they became really noisy, even though there was clearly a vast amount of tread left. On the road they literally 'howled', and eventually got so loud and obtrusive that I had to change them. I have never had this problem with good quality branded tyres - never again.

Mind you, remould tyres have risen in price so much when I last looked that there'd hardly be any point in choosing them over real tyres.
 
Top