She's a whistlin'!

Hi guys,

Had a bit of a change in engine noise this evening. The cars a 140 2.0TDi on an '07 with 83k on the clock. I pulled out of the junction on my road a little 'lively' (as traffic can be a 'mare down my road). I noticed a funny noise after that: the cars whistling!

Basically, in any gear, from about 2k, it sounds like a whistle-but it's not a constant. I can rev it in neutral and it'll do the same. There is no noticeable loss of power, the car still performs as I would expect round town. It still picks up and pulls well under load, drives with no noticeable difference. It's noisier accelerating than decelerating, and the tone seems to match the rev range. *Almost* sounds like the ol' Bill have their sirens on!

My first thought was a boost leak of some sort, but I would assume I'd feel a loss of power to go with it. I had a boost leak on my last Turbo car about 10 years ago, it was a split pipe running from the Turbo, which did emit a slight whistling where the pressure was escaping from the pipe (similar to this). But times have moved on, and I'll be honest, I don't do a lot of my own mechanical work any more so I'm not sure if it could be this simple; or if I should be looking at something else.

As most people, I don't have a huge pot of cash to throw at it being on maternity salary etc: but are there any known weak spots around the boost system? Is there anything I can do in the drive to check for boost leaks?

Advice appreciated!

Dan

Good to hear i'm not the only one who thinks boost leak. I don't get to drive it that often, so as above, I didn't really notice much of a performance drop; but my other half has been out in it all day and she said she has noticed quite a difference.

I'll get outside tomorrow and see what I can find. Cheers for the info!

Hmmm...

Done some digging. When the car is cold, it's very sluggish, but when it's warmed up, it boosts really well, albeit not as well as it should.

Anyway, I had a spare 5 minutes today so before I got some water to spray in and around (so as not to clean any potential clues away), I got my other half to rev the engine. Now, when it was cold, I noticed a kind of smoke, like oil burns when it touches something hot), and the vapour or whatever you want to call it was rising from here:



I can't say I've ever noticed before as I've never really had to do any kind of investigative work around the Turbo, but I noticed that there seemed to be a great deal of what look like oil spots peppered over everything. Here are some more pics:







Like I say, I couldn't say whether they've been there a long time or not-and when the smoke (it is a very small amount) is evident, there isn't a great deal of it, nor does it last very long.

Could a faulty DV be the cause? When you come off the revs in neutral/stationary, it sounds like the Turbo is spooling down but it's audible-like a whistle fading away. I know the DV's can be prone to failure, but I still feel more inclined to say boost leak, as the peppered oil spots are indicative of something being sprayed out.

Does anyone still think it could be a boost leak? As I say, the car is very sluggish when cold, but after a couple of minutes, it does pull really well...

Dan

Thanks for the response, much appreciated. I'm glad someone else has identified the issue because when I posted the my last response I was hoping someone may be able to shed some light over the inconsistencies I've experienced with boost. I've actually had the car looked over at a local garage, and the guy knew what it was straight away as he has an identical A4 that had exactly the same problem. I had a bit of a shock when I saw the price of a new unit so I asked if it could be repaired. He did mention the gasket and 4 screws as thats what happened to his, but he didn't mention the actuator-that cured his, so we're going to start there and see if it makes a difference.

I've got to call him tomorrow to book it in-I'll mention this to him and see what he thinks. Thanks for confirming it though-it's good to hear to from more than one person!

Hi guys,

Well, today I had a gasket replaced on the EGR cooler as this was the first port of call. Unfortunately, it hasn't solved the problem. She's still whistling under load. I've video'd it this time from outside the car whilst driving, you can hear the whistling pretty clearly here.

Any ideas as to what may be causing it? There is no boost loss, although the other day the car was going into limp mode (or whatever it's called), foot flat down it just wasn't performing. Turning it off and starting it up again straight away cures it. Anyway, here's the video, see what you think... (link will take you to my Flickr page).



...and to add, here is the car in neutral, totally stationary:

Hi mate. It's not a consistent limp mode: it doesn't do it all the time, and I can give it a good boot and it will perform as it should. It's the whistling noise that's the issue-I want to make sure nothing untoward is going on.

Out of curiosity, did you rectify your issue? And if so, how did you do it?

I've not had the car scanned to be honest-I don't have easy access to that kind of equipment. Recon Turbo sounds expensive, really aren't in a position to consider something like that at the moment.

I'll try and get it scanned somewhere tomorrow and see what comes up and go from there!

I think there's a degree of denial in this for sure (cost alone is reason enough!), but my gut is telling me it's not the Turbo. If it was the Turbo, surely the car would have issues boosting and holding boost? Limp mode seems to happen when the engine is cold. I'm not doubting the vanes may be sticking occasionally but I don't think his is the root cause. Like I said, denial!

I've found a company online that do a refurb/exchange for genuine Garret turbos and the price is quite reasonable: that's a route I may have to consider, but I think the next port-of-call is to look at is actuator on the EGR cooler. The link to the TDi thread posted above points to some people removing it completely, but I'd be concerned that it'd throw up error codes and cause more issues in the long run.

I'll have a word with the mechanic who done the gasket replacement and see what he thinks...

Ok, so, time for an update.

The issues: whistling under load and occasional limp mode. We had the following work done:

1) EGR Cooler Gasket replaced, as is a common fault (see linked thread further up). Turns out the actuator on ours was absolutely fine, but the gasket was knackered. If the actuator was knackered, it can cause a whistle/hiss under load. Had the work done, no improvement. £86 all in (I haven't the space or time to do unfortunately).

2) I said that I was in denial, but some of you guys were right. It was the Turbo. There was about 2mm play in the shaft: not good! So, we have had a recon Turbo with 24 month warranty fitted. The car had a service whilst it was in with fuel filter too. Whistle has gone and the car feels the best it ever has. £474 all in.

So, unfortunately, thats all of the money gone that we had saved for my partners maternity leave, but the car does now feel amazing. We are still have a little hesitancy between 1600/2000rpm though. The guy who did the work also has a B7 2.0TDi, he wondered wether it was the DPF as his did similar. Ours doesn't have the DPF (a call to Audi has confirmed this) as ours is the 140 TDi.

What we are planning now is rather than replace the EGR is a remap. In a few months time, we're having an EGR delete and stage 1 map taking the car to approx. 180bhp. I'm not fussed about the performance increase, but the economy improvement is appealing, but deleting the EGR will be a big weight off my mind. The guy on the phone said EGR with regards to the hesitancy before I even mentioned it: he see's it on Audi's all the time. So, to clean and delete the EGR and map it will cost £249 all in. Very reputable garage in Norwich.

So, thats the end of it for now. Thanks for your input guys, shame it was the Turbo but glad it's all sorted out. And looks like i'm getting a map out of it too, which is a positive. So, all i need to do now is convince the O/H that it needs lowering, spacing and an RNS-E and I'll be laughing!

Dan

I think I'm pushing it lowering to be honest, although it would improve handling with the map on it's way. Maybe I'll go in from that angle! I was determined to keep this car standard and mint, but it's getting hard to avoid. If I can drop it another 15mm, space the wheels and get the RNS-E I think I'm on to a winner. She's already agreed tints are the way forward for the little one in the rear, so I feel like I might be starting to get somewhere!

All I want to do is improve on whats there, little tweaks-so you can see it looks different and better for it, but only in a way that an enthusiast would notice if you know what I mean... Keep it simple!