Technical Any ideas what this noise could be?

[Govenor100]

This is a wee bit long winded so sorry if I blab on.

Car in question - 1.9 M-jet, lowered and mapped. 56 plate.

Best to start at the beginning. Had the water pump, timing belt and auxilary belt changed when my timing belt had snapped due to a frozen water pump. In this process the engine was also rebuilt with new valves and the head was skimmed etc. Before my car decided to do this, there was no abnormal noises from anywhere.

After the rebuild the garage noted that the turbo was squealing very loudly and asked me if I wanted them to check it. So they checked the pipes and turbo to say that there was no holes and nothing obviously wrong the turbo. They did however phone the manufacture of the turbo to confirm that they arent the best and are not the most reliable. I have noticed this from several posts on the forum.

I thought it was a case of waiting till the turbo blew then I would fit another one. However, a friend was down at the house and heard the car. He has a vast knowledge of building and preping rally cars as well as racing them so I was willing to listen to him. He said that it couldnt be the turbo as you can hear it start to spool (or woosh ) before this high pitched squeal appears. He suggested it would be best to take of the plastic guard to have a closer look but was 99.9% convinced it was not my turbo making the noise. I have not been able to get it up on a ramp yet to check myself.

I popped into the Fiat garage over the Christmas period and the service manage was so un helpful and refused to even come out and here the car without charging me £69. I tried to explain it to him and he suggested it could be the tensioners for the auxiliary belt.

The noise is best described to be a high pitch squeal. You never hear the noise when the car idles at stationary. When starting from cold, the noise will persist from about 1100 rpm to nearly 4000 rpm. It happens every time you change up gear. If it is squeaking when going along the motorway of I put my foot on the clutch after two to three seconds the noise will disappear until I take my foot off.

I have not got a loss in power yet, just my patience. Its starting to really annoy me haha.

If anyone could shine any light on the matter it would be much appreciated.

 

[D4nny8oy]

Just to clarify- is the Fiat garage the same place who repaired the engine?

If the squeal is closely linked to engine rpm rather than road speed, then you've got to assume it's engine related. Turbo's tend to whine or whistle, not squeal, so I'd be looking at the aux belt or cambelt first (especially as both were disturbed/replaced during the original repair).

If you can recreate the noise with the vehicle stationary, the first thing to do is remove the aux belt and retest- if the noise stops, then check the tensioners/pulleys/belt. If it continues, then I'd suspect the cambelt could be over tensioned. In that case, I'd be taking it straight back to the guys who fixed it originally.

If they heard the noise when they finished the job, then they should've investigated it, if only to confirm it wasn't a result of their work and to let you know what needs doing to fix it.

 

[Govenor100]

Thanks for that it certainly makes sense. I was considering recording it posting it on youtube and posting up a link. It was an independent garage that are family friends that did it and they claimed that by doing something to the turbo manually stopped the noise. I dont know if it was something to do with the actuator? dont know enough about turbos to say.

 

[D4nny8oy]

It was an independent garage that are family friends that did it and they claimed that by doing something to the turbo manually stopped the noise.

In that case, I can understand why the Fiat Dealer weren't going to listen and offer a diagnosis for free.

If the turbo was noisy enough to be squealling, then I certainly wouldn't recommend a customer driving away with potentially another failure which could affect the engine. Only 'manual' test with the engine running I can imagine is to operate the VGT vanes via the actuator and a pump, but i can't see how that's a useful diagnosis, compared to physically feeling for play in the shaft or inspecting the impeller wheel and housing for contact?

Did anything break off and pass out the exhaust- ie through the turbine housing and possibly damaging the turbine?

 

[Govenor100]

not that im aware. I think the turbine fins are all in good condition. my ignorance what is vgt? The service manager in Fiat didnt even know what an actuator is. so what hope you got haha

 

[D4nny8oy]

not that im aware. I think the turbine fins are all in good condition. my ignorance what is vgt? The service manager in Fiat didnt even know what an actuator is. so what hope you got haha

Variable Geometry Turbo, means the turbo's spool is dictated by altering the flow of the gases in the exhaust housing, rather than using a traditional wastegate.

IIRC, the compressor (inlet) housing intake on the mJet turns through 90 degrees, so it's hard to inspect the turbo vanes without a borescope/camera. Might be able to check the shaft for play though, just.

Haha- Service manager's don't get the job due to their mechanical knowledge, just on how well they can talk the talk in the interview while at all other times fobbing all their duties onto someone else. :devil:

 

[Gizmo89]

Hi.

Just thought id throw in my experience of a similar noise. Had a VW transporter a few years ago for work and it suddenly developed a loud squeal that could only be heard when revving or going up through the gears, once cruising at 70mph it died down, never totally went away but just died down. turned out to be a turbo bearing IRC, at least thats what the guy at the garage said it was. I dont think we ever got it fixed, it just disappeared one day.

Good luck!

 

[Lal B3N]

Does it sound like this by any chance?

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[Govenor100]

I wouldnt really say it does. To me that sounds like the guy has left his airbox off. Mine is more of a squeal. IF i can, I will record the noise later.

I wish mine would disappear very soon. It is becoming very irritating.

 

[Lal B3N]

I wouldnt really say it does. To me that sounds like the guy has left his airbox off. Mine is more of a squeal. IF i can, I will record the noise later.

I wish mine would disappear very soon. It is becoming very irritating.

Ha thats mine in the video, and just cant seem to solve it. Had boost pipes checked, turbo checked. Next is egr replaced and check pipes to throttle body and throttle body itself. Annoying when cold.

 

[Govenor100]

Have you checked your air box and pipes? sounds as if air is leaking somewhere.

 

[Lal B3N]

Have you checked your air box and pipes? sounds as if air is leaking somewhere.

They need checked too. No loss of power or any other symptoms though so thats hopefully a good sign for my bank balance lol.

 

[Govenor100]

Thats what im currently dreading. Time will tell if its the turbo or not.

 

[Lal B3N]

Thats what im currently dreading. Time will tell if its the turbo or not.

Not a huge hit if it is, ebay plenty refurbed for £400ish.

 

[Govenor100]

Ive always been in two minds about a refurbed one. will depend if and when it goes plus i defo cant sell it currently hahaha.

 

[D4nny8oy]

Ha thats mine in the video, and just cant seem to solve it. Had boost pipes checked, turbo checked. Next is egr replaced and check pipes to throttle body and throttle body itself. Annoying when cold.

Did they physically inspect the blades on the turbo compressor side? Heard that exact same noise loads of times, and it's always due to debris bending one or more of the fins. The induced turbulence makes the noise.

 

[Govenor100]

the noise is a pain in the tits certainly. If i take my turbo off can I see the fins as in the pic? I thought you needed a wee camera to see it? That pic defo is good at describing what the problem could be.

 

[Lal B3N]

Did they physically inspect the blades on the turbo compressor side? Heard that exact same noise loads of times, and it's always due to debris bending one or more of the fins. The induced turbulence makes the noise.

View attachment 97762

Not sure, but to be honest for what I seem to be able to pick a turbo up for im just going to change it for a used or refurbed one.

If that is the case a bent blade like so, how long will the turbo last? Or will it just continue its life as a normal turbo but make that pissing noise all the time?

 

[D4nny8oy]

the noise is a pain in the tits certainly. If i take my turbo off can I see the fins as in the pic? I thought you needed a wee camera to see it? That pic defo is good at describing what the problem could be.

That's just a generic pic I found, you probably would need a camera to see the blades with the turbo on the car. It shouldn't be your problem as any engine debris would have gone through the turbine side, unless it's a weird coincidence...

Not sure, but to be honest for what I seem to be able to pick a turbo up for im just going to change it for a used or refurbed one.

If that is the case a bent blade like so, how long will the turbo last? Or will it just continue its life as a normal turbo but make that pissing noise all the time?

If a fin is bent, it's knackered anyway as the compressor wheel is going to be out of balance and less efficient. If you're lucky it'll last as long as any other, if not, it may break-up and be ingested by the engine. You'll also need to find out how the debris got in (still running standard air filter?).

 

[Lal B3N]

If a fin is bent, it's knackered anyway as the compressor wheel is going to be out of balance and less efficient. If you're lucky it'll last as long as any other, if not, it may break-up and be ingested by the engine. You'll also need to find out how the debris got in (still running standard air filter?).

Hmm well going to get it booked in and take full air intake system off and get some one else to look at the turbo. Nope running a BMC panel filter.

Still not sure if it is the turbo, still runs full power like it always has, been like this for about 6000 miles now. Other than egr fault code nothing has been found yet