Turbo noise from cold?

[gac]

I noticed tonight that when driven from being stood, my car makes a slightly different noise at around 1800-1900rpm (so just as I'm about to change up a gear). It doesn't sound like the police siren videos I've heard on Youtube and the like, it sounds more like some kind of slipping belt, and it goes away after a minute or so. My old Leon used to do it as well so I'm guessing it's just a characteristic that I've only just started to notice on the Fabia, it seems to me like it's simply the fact that the oil needs to warm up a little in order to be circulated properly so when I pull off the turbo is "dry", which is of course exactly the reason I change up at 2000rpm and don't go anywhere near WOT when it's cold so it's not working too hard with no oil...

Sound like a sensible diagnosis, or have I only just noticed it because I've only just broken it?

[Lofty79]

my turbo changes note frequently, 50k ago i thought ooh its gonna pack in on me , but nope just noises. too much worry spread about, im sure itll be fine mate.

[danny6189]

Just let it warm up before you go anywhere. I always give mine 5 mins.

[chriswaite130]

Mine did this - the egr blank on the turbo had a slight leak, the pressure of the air sounded like a slipping belt. It gradually got worse though. Could be worth a check?

[softscoop]

Mine has been making a feint siren sound when cold since the day I got it. As soon as the temp gauge moves off the bottom the noise is gone.

I don't baby it when it's cold - if anything doing that takes longer to get it up to temperature. Oil is going round the turbo from the moment you turn the key. Don't get me wrong, I don't red line it, but I don't worry about whether it's up to temp or not. I just get on my way.

[billybaggins]

Mine has been making a feint siren sound when cold since the day I got it. As soon as the temp gauge moves off the bottom the noise is gone.

I don't baby it when it's cold - if anything doing that takes longer to get it up to temperature. Oil is going round the turbo from the moment you turn the key. Don't get me wrong, I don't red line it, but I don't worry about whether it's up to temp or not. I just get on my way.

I agree with that, i think letting a motor warm up at idle causes more problems. Esp turbo petrol cars, letting them warm up on idle is just fouling the plugs. They're best being driven but just not ragged.

[NoSmokeNoPoke]

Mines been making a slight noise for ages also! Like you say, get a stronger noise just below 2krpm - must be the turbo spooling up rapdily. Mines remapped though.

Is it just me that feel like im driving round a ticking time bomb and the turbo could let go at any moment!?

[Lofty79]

agree, diesel turbos like immediate but light load i.e 10 seconds in or so - as soon as oil has hit top of the engine your good to go. A cold diesel has poor emissions at first sitting idle coking up turbo, cat, dpf, etc etc. I must clarify gentle load, but move off within first 30 seconds. In winter i hate seeing people running cars in morning for half hour.

In bad cols i put a fan heater in my car and its totally warm in 5 mins then you can start the engine and drive off safely with full visibility

[danny6189]

agree, diesel turbos like immediate but light load i.e 10 seconds in or so - as soon as oil has hit top of the engine your good to go. A cold diesel has poor emissions at first sitting idle coking up turbo, cat, dpf, etc etc. I must clarify gentle load, but move off within first 30 seconds. In winter i hate seeing people running cars in morning for half hour.

In bad cols i put a fan heater in my car and its totally warm in 5 mins then you can start the engine and drive off safely with full visibility

That's a good point. Think I'm going to change my ways.

[Lofty79]

5 mins is quite excessive, but 20 to 40 seconds or so would be great for it then gentle driving until at running temp, then give her some.

[danny6189]

I always wait got the temp gauge to get to 90 before I even think of giving her a boot full. Going to get myself a couple of gauges because I know the original temp one is lazy as hell.

[Lofty79]

they all are.

[gac]

Yeah, I normally start the engine, then get belted up, and then pull away. So 5 seconds minimum before I move at all, then I just let the clutch out to roll to the edge of the drive, and then go. So it's driven off "immediately" but not driven hard.

I do have an EGR blank, so I might well check that, I have no idea what brand was used so I don't know about the quality of the parts, it's worth a look. Other than that, sounds like it's nothing serious (which I thought, given that my old Leon did it for many thousand miles, but if that had died I'd have just hybrided it, I already have a hybrid on the Fabia so I'd rather it didn't break! )

[Shadowphax]

Mine's been doing the 'more-noise-than-normal-when-cold' thing for just over a year now. It sounds a bit like the police-siren noise of a shot turbo but just very quiet.

It goes away once warmed up.

It only seems to do it when the outside temperature is a bit warmer. Over the last couple of damp and wet weeks it hasn't done it at all.

I wonder if it's just some carbon build-up in the turbo sometimes toushing the blades.

[RAPTURE]

+1

[gac]

Possibly some more to this; as the weather's cheered up a bit today I had the windows open a crack. Noticed that on uneven roads, when I was accelerating/maintaining speed, over fairly trivial bumps there was a kind of "squeaking" noise. However doing similar bumps with my foot off the accelerator, total silence. Only thing I can think of is that some of my FMIC piping is moving slightly over bumps and the "squeak" is again the noise of pressurised air escaping, which is why it's only happening under load/boost conditions. So I guess the next thing I need to do is strip as much off as I can get to and make sure my FMIC pipework is all in good condition, fastened up tight, and not moving too much. I guess it's possible that whatever's causing that is causing the odd turbo noise too...

[gac]

And another for my thread, mainly as a note to myself when I get chance to try and find out what's happening, I've noticed yet another occurrence, when I'm accelerating around a right hand bend, I get the same squealing/slipping noise. Doesn't happen going left.

[skoda_boy123]

To add to your last comment have you checked your wheel bolts? Round a right hand bend I heard noises to find the passenger worked itself loose.. just a thought , doubt its the same but 2 min check its worth a go I suppose

[gac]

Hmm, no, that's a good shout. Can't remember the last time the wheels were off, it's been a while, but it's a free 2 minute job as you say so no point not doing it...

"Expert" advice might point to a worn bush (although I don't see why that would only squeak on acceleration over bumps or right turns) so I still reckon it's got to be something to do with movement in the engine bay under certain conditions. Once I get a few hours spare I'll have to start pulling things apart and trying different tactics. The difficult thing being that none of these conditions can be replicated on a dyno so it's going to be road test after road test!