Hilux 4x4 Forum

I drive a 2001 KZTE 4x4 that has done 220000 km. When I accelerate through the rev range a strange noise occur at around 2200 rpm, and stays there as the revs go higher for as long as I give it some stick. When acceleration stops and I maintain speed (irrelevant of what speed), the sound stops. If I accelerate slowly, the sound is not there.

The sound is very well correlated with acceleration, and I now after a bit of practice, I can completely control it with the accelerator pedal. Low range, high range, makes no difference. There seems to be a correlation to revs rather than vehicle speed. It does not sound when you rev the bakkie while it’s standing still. There has to be load on the system.

Someone from Toyota, as well as another mechanic listened to it but we are all unable to pin it down.

It’s not a fan belt slipping. It sounds more like a little bird trapped somewhere in the bonnet, chirping very loudly at high pitch :wth: !

Some options I have thought of:

- Gearbox bearing – I have a brand new reconditioned gearbox, and the sound seems to come from the engine bay, and not from underneath the bakkie.

- Turbo – Why then the sound only during acceleration, and not constant speed / load?

- Bearing for the alternator – Sound does not seem to change when I switch on the dual battery system.

- Bearing on the diesel pump – Maybe due to the high correlation to acceleration under load?

- Bearing of the fan / engine bearing / water pump / oil pump? Don’t know these to well.

Any ideas on what it could be?

Thanks
Herlu

Hi Herlu

Also drive a KZ-TE but never came across this one, I have 285 000km on the clock, but one thing for sure you made me stress a bit, hopefully the clever guys on the firum will be able to assist. Good luck,

Mmmmmm...

As small bird once told me...

Maybe the release bearing? But that wouldn't sound when accelerating?

Perhaps the aircon bearing?

Vat hom na RELPH toe by TOYO service sentre.HY werk elke dag op die goed.Raad kos jou niks,anders gaan jy bly spekuleer en die probleem word nie opgelos nie.nr Cell 0837892216

Herlu

I can not tell, but maybe Thabo is right. You can start a process of elimnation by replacing the aircon bearing and tensioner bearing. I have a 2003 KZTE and the aircon takes a Nachi 30BGS10DST (52X30X22) bearing. The tensioner bearing is a 6301. I bought both at a bussiness in Frederika str Pretoria of which I can't remember the name. The dealers will sell you the complete pulley assembly for about R1300 but the 2 bearings are in the region of R250 to R300.

You need to loosen the aircon pump in order to put a puller on the pulley. There is a little washer that is on the inside of the pulley (Spline side). Make sure it does not get lost otherwise the aircon clutch will not work. The complete job should not take you longer than 45 min. Hope you find the problem.

Goodluck

If the sound is only present when there is a load on the motor irrespective of the rev range (as I understand your explanation), none of the above mentioned possibilities sounds feasible. I would rather start by looking at all the mountings .... engine and gearbox. I would also look at the pulley wheels themselves for where they could possibly be touching something and for scour marks that would indicate which pulley is touching. What you could also do is to have a second person check under the hood around the motor as well as under the vehicle while the other puts the motor under load with the clutch (in gear) while holding the vehicle with the brake. The 'driver' must be someone with a bit of savvy so as not to burn the clutch or over strain the drive-train as well as be cognisant of the other person that's under or around the vehicle. This will help you identify the source of the problem a lot easier. If the sound is not present when doing this ... i.e. only present when mobile ... then the problem will be somewhere in the drive-train.

Hi Herlu
Ive got a 2002 KZTE 4x4 with about 210 000km on clock. I have had the same noise(sounds like what you have) for the past 6 months .Its a wyning type of whistle sound during acceleration. :problem: Mine I can also hear if the bakkie is standing out of gear and I give the accelerator a bit of stick.I took the bakkie to Steves Auto Clinic in CT, they thought it was a leaking exhaust gasket, removed the manifold,but gasket ok,then checked the Turbo.They said they saw a small mark on the turbo compressor blade,not a piece missing, just a mark, which they say could account for the noise.It is definately coming from that region.
You must remember the speed of the turbo is relevant to the demand on the engine, so once you are in top gear and cruising, as is in my case, the noise is gone.The turbo is virtually on idle when you cruising at 120km/h and under the power band,but when you "gee gas", the turbo is under heavy demand and will spin up a heluva lot, causing the noise.
I was very concerned at first,and wanted to imediately replace the turbo,but considering they are between R10 000 and R15 000 I changed my mind.
SAC also did a dyno test when the bakkie was there and it was all ok,so that made me feel at ease.They were very leka about it, I only paid for the dyno test, they never charged me for any labour,as they had really not changed anything and the noise was still there.
Ive been driving with it since and its fine on power etc, just the noise is annoying at times.
I hope it helps you out a bit,i suggest you prob look at checking out your turbo.
Cheers
Ian

Thanks Guys,

It’s really cool to see how people try and help on this forum. We are never alone with a Hilux problem, one of the pro's of driving such a cool car!

I replaced the aircon tensioner bearing as it felt loose, as well as all the vbelts. The other pulleys (aircon, alternator) seems solid, don’t think it’s them.

I will be trying the standstill test as Muddog suggested, and my next move will certainly be to take it to Steves. I am so tired of taking it to mechanics that gives these strange opinions, half of which I know can simply not be true due to pure logic. Like the other day at the gearbox place the oke was lying under the car, and he was arguing with me that the front prop shaft is always turning when the vehicle moves, while I said it only turns once you engage 4H of 4L and / or lock the front hubs. I dared him to try and turn the freaken prop, and after a long time he did. UUUm, that’s strange... was his reaction, as he could turn it, meaning its not locked to the wheels or transfer case. How must you trust someone that claims to have 20 year gearbox experience if he does not know the 4x4 setup of a hilux. He incidentally also drives the same model in petrol.

I will keep you guys posted.

Had a similar issue on my KZTE (260 000Km)... After much sweat and tears I discovered that the crankshaft pulley had issues. There are 3 pulleys on the crankshaft and a rubber seal / boot keeps the 2 larger pulleys attached to the smaller front pully. This had worn and now this frontal pully was free to move back and forward along the shaft. Whenever i accelerated it moved back and started touching / hitting against th e inner pulleys... quick to fix once the problem was found!!

His sound sounds like it is been made by the freqency of the motor(revs). Have a look at the cover that goes over the propshaft at the transfer. If there is cracks it will make a noise as soon as the engin are at a certen revs. Also look for heat displacment plates on the exhaust(plates welded onto exhaust to deflect heat to gearbox) if all the welding is in tact.
Hope this will help.

Just thought I would mention another possibility. Check the radiator cowling. When accelerating the engine obviously moves under torque and depending on the engine mounts being worn the engine will move more which could result in the fan just slightly touching the cowling. Or even the cowling which has moved slightly and now is in a position where the fan touches it. Just a thought.

We have something similar with Rafs's Jeep where the cowling is cracked at the bottom and when under torque the engine touches it slightly causing a soft squeaky/chirpy sound.

On my 2.7 I also had a sound similar to that and it turned out to be the speedo cable.

This sounds like a turbo or induction line problem.
We have these problems allot here in Angola due to the dust, fuel & oil conditions.

When you accelerate the boost pressure will be high, if you have a small hole in the induction line or if one of the clamps are a little loose you will get a whistling sound while accelerating.
The easiest way to identify a leak in the intake system is by letting the engine idle, then use quick start to spray along all the sealing areas (and aftercooler if fitted). If there is a leak the rpm will pick up automatically.

The easiest way to identify a leak in the intake system is by letting the engine idle, then use quick start to spray along all the sealing areas (and aftercooler if fitted). If there is a leak the rpm will pick up automatically.

Can you even do this with Diesel engines?

It only works on diesel engines.
We do this test on all diesel engines, from 1.6liters up to 10 000Nm 16 Cylinders.

Het al daai metode op petrol enjins ook gesien werk.

Dit bly maar die maklikste manier.
Solank die quick start vir niks anders gebruik word nie is dit OK.

Ja kyk daardie quickstart is die vinnigste manier om 'n diesel enjin op te dons!

Herlu wrote:I drive a 2001 KZTE 4x4 that has done 220000 km. When I accelerate through the rev range a strange noise occur at around 2200 rpm, and stays there as the revs go higher for as long as I give it some stick. When acceleration stops and I maintain speed (irrelevant of what speed), the sound stops. If I accelerate slowly, the sound is not there.

The sound is very well correlated with acceleration, and I now after a bit of practice, I can completely control it with the accelerator pedal. Low range, high range, makes no difference. There seems to be a correlation to revs rather than vehicle speed. It does not sound when you rev the bakkie while it’s standing still. There has to be load on the system.

Someone from Toyota, as well as another mechanic listened to it but we are all unable to pin it down.

It’s not a fan belt slipping. It sounds more like a little bird trapped somewhere in the bonnet, chirping very loudly at high pitch :wth: !

Some options I have thought of:

- Gearbox bearing – I have a brand new reconditioned gearbox, and the sound seems to come from the engine bay, and not from underneath the bakkie.

- Turbo – Why then the sound only during acceleration, and not constant speed / load?

- Bearing for the alternator – Sound does not seem to change when I switch on the dual battery system.

- Bearing on the diesel pump – Maybe due to the high correlation to acceleration under load?

- Bearing of the fan / engine bearing / water pump / oil pump? Don’t know these to well.

Any ideas on what it could be?

Thanks
Herlu

If it does it under a load, check the turbo vacuum hose or any other turbo boost pipes (turbo in to to turbo out). Mine developed a strange noise today (similar to yours but it does it without being under a load). I have two suspicions, one being the air con pump bearing or two the timing belt tensioner pulley. I've parked the vehicle for now in order not to take any chances. I'll take off the air con belt belt and run it to see if the noise goes away, if not, timing belt tensioner.

MAKE SURE TO IDENTIFY THE TYPE OF NOISE (Metal screeching, whistling air or screeching fan belts etc).

You would clearly hear if it was the turbo (whistling sound) and on top of that it gives you a warning sign (oil dripping out of the turbo housing area, when it's oo late already ), metal screeching would indicate a pending bearing failure (pulleys/tensioners), etc. I've had lots of sheit with my KZTE (not the vehicles fault but previous owners and so called mechanics who worked on it, word of advice rather ask the guys here before you decide to take it to a "mechanic". There's only 2 guys I trust with my vehicle. one of them being Ralph from Toyoservice in Krugersdorp, the other B&E auto in Benoni.

Good luck, let us know!

Mine had a high freq. vibratiing noise , only under power, above 1800rpm

Took a year to find.

Fixed the exhaust bracket just after the turbo.No more noise ....

Hope you find it SOON >>

Hi

Did you manage to find out what the noise was/is I bought a KZTE in Dec and the prev owner told me it's the turbo as you can hear it if you accelerate past the 2000rpm mark.

Let me know please

Hi, I had a similar problem with my KZ Prado. the sound sounded
like the veins on the turbo were rubbing on the housing round about the 2000 rpm range. Took it to a Diesel expert who was convinced that the turbo was on its way out. After tacking the turbo out and letting him have a look at it he was defiantly convinced the turbo was stuffed but wanted to charge me 7k to refurbish it. I wasn't happy with the quote so i went to Turbo Exchange in Parrow Industria who quoted me 4k (2 Years ago) to refurbish it. after pulling the turbo apart they found nothing wrong with the turbo but because they stripped it i had had to have it reconed otherwise i wouldn't have any warrantee

Long story short check around the EGR valve and piping turns out that the bolts holding the EGR valve had somehow worked loose and that's was what was causing the noise as the boost pressure was escaping causing the weird noise.tightened the loose bolts. no noise since then............ a very costly pointless exercise. But try all cheap avenues before the more costly expert advice avenue.

On the plus side i can can highly recommend Turbo Exchange fore any turbo related problems.

Hope it is a cheap fix.

Hi

I had a similar sound on my KZ. It turned out to be the tensioner pulley that was slightly dry. Took it off, cleaned it, oiled it .... problem solved.