Odd new turbo noise

-bobda- · Apr 23rd, 2006, 00:05

I've suddenly developed a new noise when the car is under load (ie - not at idle) at around 1500-2300 rpm.

Where I used to get a hint of turbo whistle, I now get a noise which can only be described as a whirring/whooshing noise. It sounds like something spinning and it only does it when accelerating, and stops as gradually as it starts.

It's only started in the last day and the performance doesn't appear to have altered much, although (and it may just be my imagination) the turbo doesn't seem to be following itself through on gear changes as much as it used to and the engine appears to last a fraction of a second longer after I flick the key off.

What could it be? I'm almost certain it's something in the turbo area, but I'm not well versed on the workings of turbos, so I don't really know what to look for.

It's a 2002 S40 1.9 TDCi which has done 61000 miles with a remap at 60000 (if that makes any difference).

Apr 23rd, 2006, 01:54

Noise could be an air leak?
Or could it be overboosting do you think?

Don't see why that should make it run on though. Is the temperature ok (not too hot?) BTW if you ever find it won't turn itself off, just let the clutch up with it in gear and foot on the brake, to stall it. It can happen you know!

What happens if you leave it to idle for a fair while before you turn it off? Does it still run on then?

Dunno much about diesels I'm afraid, although I guess they're just like petrol engines but smellier

(Only joking!

)

-bobda- · Apr 23rd, 2006, 14:53

It could be an air leak, which may have reduced the whistle I was getting before.
I hear a lot of things about turbo hoses splitting, but I don't know where to start looking to check.

It's not running on as such, just maybe having one more tick before actually going off completely.

It's not running any differently (in terms of temperature and idle speed etc) as it was previously.
Driving it today, the turbo doesn't seem to be as progressive as it was previously, it's kicking in, but it's all coming in one lump whereas before it was a lot smoother.

-bobda- · Apr 24th, 2006, 11:55

A post on the Honest John website has advised me to check for air leaks on the output side of the turbo, which I did yesterday.

I came across what appears to be a patch of oil which looks like it is coming from the top part of the turbo manifold (I think).

This picture shows where the patch is, could a new gasket on this join solve my problem?

Apr 24th, 2006, 16:29

Is the turbo oil cooled on your diesel I thought they were water cooled? If you think the oil is coming from there then you could try a gasket as a cheapo thing to see if it fixes it. But be sure because oil is a funny thing, it can blow around all over the place so might be coming from elsewhere.

Cheers, Pete

-bobda- · Apr 24th, 2006, 22:29

Yeah, it's oil cooled.

I've had another good root around under there this evening and took my dad out for a listen, who agreed that it is DEFINITELY an air leak either before or (more likely) after the turbo.

Now to find where it's coming from...

PS - I think it's getting louder.

Rooster · Apr 24th, 2006, 22:39

Take the 3 10mm bolts out, if it still has all 3 in, they usually come loose and drop out, clean the seal and mating surface up and refit putting abit of locktight on bolts,

It could have been like that for ages, just it will probebly be running more boost than it was now so will be pushing more air through causing noise,

Petrol turbos are water cooled mitsubishi turbos and diesels are oil cooled garratt turbos

-bobda- · Apr 25th, 2006, 11:15

Right...

I'm a bit more convinced that the bit in the photo above isn't what's at fault.
There is a small patch of oil (it seems fairly fresh) on the bottom of the input hose to the turbo, a lot more than on the inlet manifold in the picture above.

What could cause a leakage of oil like this just before the turbo?
I'd try and explain where it is a bit better, but it's not easy to describe!

I'll see if I can take a photo this evening to show where I found the patch, or if anyone has a diagram of a turbo engine where the turbo is on the back of the engine, I'll show where I found it on that.

Apr 25th, 2006, 11:35

You sure the oil's not just blowing back from a leaky cam cover gasket?

-bobda- · Apr 25th, 2006, 12:07

It could be, but it's right by the joint of the hose which goes into the turbo.

Apr 23rd, 2006, 00:05	#1
-bobda- Member Last Online: Nov 5th, 2007 14:15 Join Date: Jan 2006 Location: Leeds	Odd new turbo noise I've suddenly developed a new noise when the car is under load (ie - not at idle) at around 1500-2300 rpm. Where I used to get a hint of turbo whistle, I now get a noise which can only be described as a whirring/whooshing noise. It sounds like something spinning and it only does it when accelerating, and stops as gradually as it starts. It's only started in the last day and the performance doesn't appear to have altered much, although (and it may just be my imagination) the turbo doesn't seem to be following itself through on gear changes as much as it used to and the engine appears to last a fraction of a second longer after I flick the key off. What could it be? I'm almost certain it's something in the turbo area, but I'm not well versed on the workings of turbos, so I don't really know what to look for. It's a 2002 S40 1.9 TDCi which has done 61000 miles with a remap at 60000 (if that makes any difference). __________________ Andy. --- 2003 S40 T4 Sport Lux.

Apr 23rd, 2006, 14:53	#3
-bobda- Member Last Online: Nov 5th, 2007 14:15 Join Date: Jan 2006 Location: Leeds	It could be an air leak, which may have reduced the whistle I was getting before. I hear a lot of things about turbo hoses splitting, but I don't know where to start looking to check. It's not running on as such, just maybe having one more tick before actually going off completely. It's not running any differently (in terms of temperature and idle speed etc) as it was previously. Driving it today, the turbo doesn't seem to be as progressive as it was previously, it's kicking in, but it's all coming in one lump whereas before it was a lot smoother. __________________ Andy. --- 2003 S40 T4 Sport Lux.

Apr 24th, 2006, 22:29	#6
-bobda- Member Last Online: Nov 5th, 2007 14:15 Join Date: Jan 2006 Location: Leeds	Yeah, it's oil cooled. I've had another good root around under there this evening and took my dad out for a listen, who agreed that it is DEFINITELY an air leak either before or (more likely) after the turbo. Now to find where it's coming from... PS - I think it's getting louder. __________________ Andy. --- 2003 S40 T4 Sport Lux.

Apr 24th, 2006, 22:39	#7
Rooster Speed freak Last Online: Apr 3rd, 2020 22:04 Join Date: Nov 2003 Location: Yorkshire	Take the 3 10mm bolts out, if it still has all 3 in, they usually come loose and drop out, clean the seal and mating surface up and refit putting abit of locktight on bolts, It could have been like that for ages, just it will probebly be running more boost than it was now so will be pushing more air through causing noise, Petrol turbos are water cooled mitsubishi turbos and diesels are oil cooled garratt turbos __________________ 04 XC90 D5 --- Big bus 00 pug 306HDi --- Run about 88 pug 309GTi --- Project track car 07 CB600 Hornet --- 2 wheel fun

Apr 25th, 2006, 11:15	#8
-bobda- Member Last Online: Nov 5th, 2007 14:15 Join Date: Jan 2006 Location: Leeds	Right... I'm a bit more convinced that the bit in the photo above isn't what's at fault. There is a small patch of oil (it seems fairly fresh) on the bottom of the input hose to the turbo, a lot more than on the inlet manifold in the picture above. What could cause a leakage of oil like this just before the turbo? I'd try and explain where it is a bit better, but it's not easy to describe! I'll see if I can take a photo this evening to show where I found the patch, or if anyone has a diagram of a turbo engine where the turbo is on the back of the engine, I'll show where I found it on that. __________________ Andy. --- 2003 S40 T4 Sport Lux.

Apr 23rd, 2006, 01:54	#2
peteS40 Guest Location:	Noise could be an air leak? Or could it be overboosting do you think? Don't see why that should make it run on though. Is the temperature ok (not too hot?) BTW if you ever find it won't turn itself off, just let the clutch up with it in gear and foot on the brake, to stall it. It can happen you know! What happens if you leave it to idle for a fair while before you turn it off? Does it still run on then? Dunno much about diesels I'm afraid, although I guess they're just like petrol engines but smellier (Only joking! )

Apr 24th, 2006, 16:29	#5
peteS40 Guest Location:	Is the turbo oil cooled on your diesel I thought they were water cooled? If you think the oil is coming from there then you could try a gasket as a cheapo thing to see if it fixes it. But be sure because oil is a funny thing, it can blow around all over the place so might be coming from elsewhere. Cheers, Pete

Apr 25th, 2006, 11:35	#9
peteS40 Guest Location:	You sure the oil's not just blowing back from a leaky cam cover gasket?

Apr 25th, 2006, 12:07	#10
-bobda- Member Last Online: Nov 5th, 2007 14:15 Join Date: Jan 2006 Location: Leeds	It could be, but it's right by the joint of the hose which goes into the turbo. __________________ Andy. --- 2003 S40 T4 Sport Lux.

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