Really Weird Tick / Rattle Sound

[Homelux]

I have a 2008 Toyota Hilux 3.0L D4D RWD with kun16 engine.

For the last week or so I have been getting a strange tick or rattling sound. It comes on kind of randomly, but seems to be triggered worst by driving up hills and slowing down.

It can be as little as one tick or a constant rattle for about 5 seconds. Sometimes it will come on and off several times a minute but most of the time I can go 30-60 minutes driving without hearing it at all.



The sound does not change with rpm and if you stop the car when you hear it it might continue to tick occasionally for 10-60 seconds. Also I can idle the car for 30 minutes straight and never hear it.

Sound seems to be at its loudest on the driver's side and has a metallic or plastic tone to it.



Hoping someone out there has a clue because I don't, thanks from NZ.

[Rob_Wood]

Without going into the long list of "Cable Ties on the Tail Shaft" possibilities, have you been driving in muddy terrain or on dirt roads recently? Could be as simple as bits of gravel flying out of the tire treads?

[Homelux]

It is now doing it occasionally at idle too.

[Gipsy]

Check for an exhaust leak

[Homelux]

Without going into the long list of "Cable Ties on the Tail Shaft" possibilities, have you been driving in muddy terrain or on dirt roads recently? Could be as simple as bits of gravel flying out of the tire treads?

Definitely not gravel in tires etc. we live on a gravel road and are used to that. What are the chances there is a stone flicked into a turning part like the alternator? Any other ideas along these lines?

Truck is running perfectly, you wouldn't know anything was wrong unless you hear the sound. No loss of power, starts smooth and perfectly.

About to pull it apart now and see what I find, will check exhaust.

Any suggestions appreciated.

[hiluxxury]

Is there a leaf in your heater fan?

[Homelux]

Is there a leaf in your heater fan?

Fan is off when it is happening and it definitely sounds like it is coming from outside the cab.

It is so darn illusive I just spent 20 minutes listening to various components with an automotive stethoscope and nothing happened but then when I go to turn off the car it makes the rattle real quick and stops again before I have a chance to get back under the hood grrhh

[Rob_Wood]

Definitely not gravel in tires etc. we live on a gravel road and are used to that. What are the chances there is a stone flicked into a turning part like the alternator? Any other ideas along these lines?

Never say Never. I'm on a dirt road too and I've had stones in all sorts of weird & wonderful places.
Hub Caps, Bell-Housing, Exhaust, Air-Con clutch, Dash Fan and probably many more.

About to pull it apart now and see what I find, will check exhaust.

Be careful what you actually "Pull Apart". My hilux had a small bracket that was there to hold hoses and wires in place, the mounting (stress fractures) broke through and caused a rattling sound. Cos the cables & hoses were holding it in place it took forever to find the actual broken bracket. Once found, removed the broken piece and no more rattle. Hoses & cables don't seem to be rubbing on anything or in any other way affected so it might take me some time to get around to making a new bracket. My old falcon had a loose baffle in the muffler, very annoying rattle that outlasted the car because all else was still working and I wasn't spending money just to fix a noise that wasn't affecting anything more than my sanity. Now my head head only shakes when I say it should.

Any suggestions appreciated.

[Homelux]

Thanks for your input Rob, I pulled out a few things to check for loose parts and or stones in things.

When I went to put it back together the part of the drive belt tensioner that one of the pulleys bolts into broke off when I went to bolt it up. Its a new tensioner so it might be a dud or I overtightened it, but I'm fairly sure I didn't. Either way perhaps the noise was the cracks forming and being worked back and forth.

I won't know until the new tensioner arrives on Wednesday now.

[1tuff4b]

I have a similar ticking / rattle noise also, although mine is in a v6 Prado. My noise seems to be coming from within the dash cluster. I’ve tried compressed air up under the dash, noise is there with car idling, driving, climate control on and off. It’s starting to drive me mad!!

Will be following your progress on this


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[Rob_Wood]

I have a similar ticking / rattle noise also, although mine is in a v6 Prado. My noise seems to be coming from within the dash cluster. I’ve tried compressed air up under the dash, noise is there with car idling, driving, climate control on and off. It’s starting to drive me mad!!

Will be following your progress on this


Sent from my iPhone using Tapatalk

Check for a leaf stuck in the fan. I dunno about Prado, but "some" vehicles might have the fan separate from climate control. Climate control indicates temperature and not air flow is all I'm thinking.

[Rob_Wood]

Thanks for your input Rob, I pulled out a few things to check for loose parts and or stones in things.

When I went to put it back together the part of the drive belt tensioner that one of the pulleys bolts into broke off when I went to bolt it up. Its a new tensioner so it might be a dud or I overtightened it, but I'm fairly sure I didn't. Either way perhaps the noise was the cracks forming and being worked back and forth.

I won't know until the new tensioner arrives on Wednesday now.

Is the tensioner arm straight or banana shaped? Not important, just make sure it's not upside down when you put it in.
Stress fractures forming aren't usually something you'd hear in smaller bits of steel unless there is already a crack that is "clicking" as the stressing actually occurs. Also remember not to over-tension your belts. I used to do this so I leave that job to the mechanic nowadays.