Car whistling when accelerating when on Turbo - Suggestions?

qwerty321

A few days ago I noticed that my Laguna 2.2 dCi has developed a whistling noise when accelerating in the Turbo range (1800-3000 RPM or so). Doesn't seem to have affected power but had the car for 5 years and I haven't noticed this before. Car is a 53 plate with 112k on the clock.

Mechanics took it for a test drive and had a look around but couldn't spot anything. Coolant and oil was a little low so they topped that up. Might just be me but it didn't sound as loud afterwards, could just be my mind playing tricks on me though. Their advice is to keep an eye (or ear) on it for now and see how it behaves over the next few weeks. If it gets worse, they will investigate it further.

If it does turn out to be the turbo then I'm looking at £4-500 to get it sorted. The car is probably worth just over £1000 but I'm considering getting it done if I have to. Id like to keep the car for another year or two and generally it has served me well, If I have to spend £500 to last two years, I feel as though it would a decent enough investment. I would rather do that then but a cheap car that I don't know much about. Don't have the funds to get a decent car, by my standards, right now.

car-man

I had a similar thing recently with my Peugeot van...turned out to be an exhaust leak, however, my neighbour has a 1.9 version of the Megane which developed this type of noise and had a turbo fail.

Keep a regular watch on it, especially the oil level and whether there is any smoking out the exhaust.

qwerty321

Thanks. Haven't seen any smoke when driving it so far.

Will have to check the oil manually because when I had an MOT/service a couple of months back, after it I sometimes but not always get the SERV light on and the OBC oil level indicator flashing to say oil is low. However, when the oil is checked manually, it seems fine. Might have been that the sensor got knocked around.

rongood

Another one for the exhaust gone here, our turbo connect van whistled when the back box went.

qwerty321

One thing I forgot to add was the sound only seems to be present when the car is in gear and accelerating. It doesn't happen when the car is being revved in neutral.

Just in case that makes any difference to the diagnosis. I will get the exhaust checked out though.

Wardy257

A leak somewhere, could be a breather pipe or the exhaust.

FZR400RRSP

Definitely sounds turbo related, not exhaust.
Check the pipes around the turbo, see if any are loose or split.
That's the cheapest option.
Even if the turbo is guffed, it shouldn't cost £400-£500
There are umpteen secondhand units out there for £100.

un1eash

Also try getting the car up to motorway speed and keep the revs and speed constant with the turbo working. If power or speed slowly drops off you have a small leak somewhere, maybe the intercooler. Its hard to spot at low speeds as your constantly revving and the turbo is creating boost.

IronGiant

Despite two members reporting whistling from an exhaust problem?

qwerty321

Tried this today and everything seems OK. Maintained speed at 70 MPH and RPM stayed at around 2000 RPM in 6th Gear. No drop in speed or RPM.