strange vibration noise

[Yorkshire4x4]

Hi I will try and explain this the best way I can

When I drive my kjdj95 90lwb auto, I get a vibration that I can hear at the back /centre of the car. I would say the vibration only happens at 1500rpm or when the car goes from 1st to second gear or when i rev the engine and ease off the gas pedal. I have checked the back door, the rear bumper,crawled under the car, and checked the exhaust but unable to identify or hear it from the outside of the car. my mechanic has no idea so again i'm asking you LC90 experts for your opinion and knowledge as this forum has resolved many complex landcruiser issues for me in the past . I think it may be something vibrating at the front of the engine and travelling through the exhaust for example the exhaust manifold guard . i changed the exhaust 12 months ago. im hoping its not the gear box. any ideas any one please? or has anyone had similar issues with their Land cruiser 90s

Thanks

 

[Michael Montgomery]

Noise & vibrations are always hard to locate but if its when you drive then its most likely some moving parts affecting through body.

Had an issue the other day with my 80 series that become ever more evident with noise & vibration, turned out to be the main engine pulley bolts came loose. But you wouldn't have thought so THB but thats as simple as things can be sometimes.

Hopefully you isolate the issue without to much worry....let us know how you get on

 

[Shayne]

Exhaust is the number one suspect but a rattle that annoyed me for months turned out to be my jack loose in the locker lol

 

[Chris]

So are you saying that you can hear it when you rev up and ease off the gas, the car isn't actually moving? If that's the case then it does sound like some sort of harmonic issue rather than some moving part - like a prop shaft banging about.

Is it possible to get someone to hold it at the revs it makes the noise at so you can crawl around and have a look and listen?

 

[flint]

As said, could be the exhaust. Worth checking for clearance around where it goes over the back axle, It might be fine when stationary, but when under load the exhaust does move about a bit.

 

[Yorkshire4x4]

As said, could be the exhaust. Worth checking for clearance around where it goes over the back axle, It might be fine when stationary, but when under load the exhaust does move about a bit.

Hi guys thanks for the replies and advise I held the revs and asked a friend to get under and no
joy! So i will drive the cruiser until summat goes bang ! it just has to be the exhaust

 

[StarCruiser]

As Chris has mentioned it's not clear whether this only happens when moving or you can replicate it at a standstill with only the engine turning. Perhaps you could let us know?

First thing to do is remove everything from the truck that isn't bolted down or otherwise held and see if it happens then.

 

[Yorkshire4x4]

Hi thought I would post a little update!! The vibration also happens when stationary!! I have just spent ages under the truck and noticed my rear axel looks a bit worse for wear!! I'm getting it welded on Monday so will see if this was the culprit

 

[Michael Montgomery]

That’s always the problem with vibrations and noise. Just have to diagnose then one by one. Hopefully you’ve found it.

 

[Yorkshire4x4]

That’s always the problem with vibrations and noise. Just have to diagnose then one by one. Hopefully you’ve found it.

Thanks Dervis my rear axel has always looked a bit rusty hope the rest of the suspension is OK! Like some one mentioned the Lc90 are 15yr old!! I've owned many a cars but none has give me as much pleasure than the Lc90!!

 

[Yorkshire4x4]

Hi can some one please advise if they have ever had their rear axle brackets welded and what's the best way to get it done so I can instruct my mechanic !! I also noticed a few cables in my picture may they be are the culprits vibrating

 

[MarkW]

Had mine done a few years back but can't advise on how I'm afraid, I just took it too a local engineering place

 

[Yorkshire4x4]

Had mine done a few years back but can't advise on how I'm afraid, I just took it too a local engineering place

Hi mark would you be able to confirm if metal plates were used and has it survived ?? Thanks

 

[Yorkshire4x4]

Had mine done a few years back but can't advise on how I'm afraid, I just took it too a local engineering place

Hi mark would you be able to confirm if metal plates were used and has it survived ?? Thanks

 

[MarkW]

Yep metal plates and it’s survived very well. I gave the engineers my axle and a spare one I had and they repaired the mounts on the top and also reinforced all the other mounting points while they had it.

That was summer 2013 and since then I’ve done 6 trips in Morocco and the Western Sahara with no further problems.

 

[Yorkshire4x4]

Hi, Guys, this has now been resolved .... The problem was the fuel pipes were loose and banging against each other or the body that's one problem another three to resolve

 

[Michael Montgomery]

Hi, Guys, this has now been resolved .... The problem was the fuel pipes were loose and banging against each other or the body that's one problem another three to resolve

Good Job there happy for you...... often a surprise where these noises stem from.

 

[Damien]

I've got a vibration in my Prado that I have been unable to resolve.

On hills it would start to vibrate a lot. But it never made any seriously bad thumping sounds. It just had a shudder that then went away.

I've done the flex plate. I've done the engine mounts. I've done the transmission mount. I've done the u-joints on both prop shafts but not the cardan on the fronts of them ( yet ) ...

I did the exhaust with an after market set of headers.

For awhile after all this it definitely seemed better. When this problem first developed it was I believed mechanical so I decided to just do all that in one go and that definitely seemed to help.

It has about 390'000 on it now so it is getting on a bit.

After I did all the above ran fine for a few months then about three weeks ago a long drive a new vibration developed. This is different now and I have identified that it seemed like the engine was having a bit of a stumble and that this was causing other further mechanical sounds further along the drive line.

I checked it for fault codes by the normal checkout light procedure. No faults showing.

So I did the plugs and leads anyway. This made a definite improvement and it ran great again for a bit.

But now the stumble is back. I managed to catch it yesterday while either in N or P. On revving up to about 2100 rpm it gets a definite stumble and an odd mechanical noise that almost sounds like the flexplate ( but I have done that ). Also it only sometimes does it and if I unplug the leads or the MAF sensor it goes away again for awhile.

Sometimes I can rev her all the way through to 3000 and she is fine. But if we take it out and drive it will always stumble under acceleration. I can hear some mechanical noise as a result but I think this is just being magnified by the fact the motor is having something interesting going on in the electrical department. At least I think it is. I thought it could be the MAF or the coil packs or the fuel filter so I was going to replace those next. Any other suggestions of what to look for?

Also I have asked this before but has anyone ever put a later / other region ECU in that supports OBII. I feel like if it just had a slightly smarter brain this would be easier to diagnose.

As I final note about 8 months ago I also did the heads. When I took them apart they had been Glyptal ( red stuff ) coated on the inside. When I cleaned up the heads this stuff got cleaned off. I vaguely remember something about this being a service item to stop the plugs jumping or some other oddity?