Hi,  I got a whistle/high pitch screaming noise coming from the car when under load. the problem is that the car doesnt do it all the time when under load and there is no change in weight at all. sometimes when i rev is then its up to temperature to 4000 Revs it will squeal and sometimes it does not and the same when i put my foot down in 3rd gear it does the same. sometimes i can feel the power come and do as i floor it. 

i have replaced all of the intercooler hoses on the car and the probem still goes on. my friend has felt the turbine on the turbo and says it feels fine, just like it should. there is black smoke when i floor it and revs from 2k to 3500k but i didnt think much of it as its a diesel. it doesnt smoke at all when im driving normally. My only thoughts if that the gaskets are leaking? 

i need help thank you and sorry for the bad grammar. 

Have you checked/replaced the Aux drive belt ? There is a chance it just needs a new belt.

No I haven't. It's original with the car I believe as we've owned the car since 2008 when it had only 9k miles on it and now it has 143k. The belt doesn't even looked cracked, it does look shiny though. Everything seems to work fine too, the AC comes on fine and the alternator keeps a steady voltage while driving (I got a plug in volt meter to the 12v port) ect ect. But when I am driving with 3 or more people in the car accelerating up a hill. The power does drop and come back a couple times

23 minutes ago, ciaranJM said:

9k miles on it and now it has 143k. The belt doesn't even looked cracked, it does look shiny though.

For the sake of £30 and 30 minutes work change the belt, it's well over due. 👍

Has the timing belt never been replaced?  So it's 16 years old and 143k miles? 😮 

If so, I'd make that a priority, the aux belt has to be removed for that so they're generally replaced at the same time.

Ofcourse the timing belt had been replaced. It got replaced at 70k and I'm due to do it again now. Just the belt driving the alternator (accessories) has not. I got videos of the noise on my dash cam which I'll upload when I am home 

 

So are you saying the timing belt was replaced but the auxiliary belt was re-used? That seems rather false economy.

I probably was replaced back then? I have no idea because I was too young 😂 but either way I really don't believe the aux belt is causing me any problems

the microphone on my dash cam isnt good enough, so you cant hear the whistle at all. all you really hear is static 😄

So almost 3 months later and 3,500 miles later. I now got slightly reduced power and a engine systems fault warning on the desh and it comes up with turbo under boost pressure. These turbos are VGT? I'm guessing the little flappy doors are stuck and they need a clean? 

Yes, it's a VNT turbo.

These use an electronic vane actuator which is a rectangular plastic box mounted on the turbo itself.  You can disconnect the arm from the actuator box and then manually see how far you can move it in each direction.

If you can't move it, the vanes are totally stuck and probably beyond cleaning.  If you can only move it a few mm or it feels really stiff then you may get away with cleaning them.

I must admit though, the fact that it whines suggests more likely a boost leak or a worn turbo bearing than sticky vanes.

Heya. I had a feel of the arm, it did move but not as much as I thought, maybe maybe half an inch in total? I have no idea how much it is meant to move. 

She's at 146500 now, had an change every 7k or so since 9000 miles (thats the millage we bought her at). I'd be quite gutted if it was the bearings. I've got brand new silicone high pressure pipes on too. When I drive with the windows down, I do notice a lot of "PHHHHHHHF" when the turbo spools. I'll upload a video on yt and send a link. 

Thank you for replying, I'm quite surprised with it being an old thread 

Hello, these are the vids (I obviously don't drive like this normally, it just for video purposes) 

 

 

 

 

 

Sounds like a boost leak to me.

Silicone pipes don't always seal well on OE parts.  Top tip is to use some hairspray around the inside edge before fitting as that helps them seal.

You may find one of the metal boost pipes is damaged.  The bracket welds can fail which then leaves a thin air gap that's hard to see but will blow under boost.

You may even find that the intercooler is damaged.  They tend to fail along the plastic end tanks or get pierced by stones through the grill.

A 'smoke test' might help find the leak in the boost system.

Thank you for the tip about the metal boost pipe Tom, that is actually pretty handy to know! 

And yes you are right! The intercooler has got a crack in it! Im very thankful the turbo is (probably) okay, I'll have to get back to say if the turbo is good because I've never noticed the intercooler being broken before i noticed the squeak, the crack must of gotten bigger since I looked. I got a new intercooler on the way! I'm very chuffed it has been found. 

She's all fixed and absolutely flies along now for her age

On 2/12/2024 at 5:04 PM, ciaranJM said:

She's all fixed and absolutely flies along now for her age

Always nice to see a happy ending!