Thread: TD5-Chirping/Whistling noise

Get them to check the exhaust manifold studs and nuts.

Yep.... just had mine done, 4 studs were broken and the manifold warped.

All sweet again now.

Thanks...so it is not an unfamiliar sound and only occured upon acceleration? Do you reckon that would be covered under warranty ie is it a major or minor issue...thanks....Please note my technical expertise is very limited...but I am learning ,

Regards

Stevo

I would push to get it done under warranty if you can. It shouldn't be classed as "normal" wear and tear.

Id be calling warrenty repair and heres why it happens.... (assuming it is actually the exhaust system making the noise)

this is whats happened

For some reason, gasket failure, stud failure, loosening of the mounts, deformation of the manifold or if murphy doesnt like you deformation of the heads a small gap has developed between the joint of the engine and the exhaust manifold or the turbo and the manifold. If you're very lucky its a failure of the little pipe that provides boost pressure for actuating the wastegate on the turbo or the joint for the EGR system.

here is why it only whistles first thing in the morning or when your on the noise.

First thing in the morning when you jump in and fire up everything is cold and the gaps that might exist are at their widest so it will whistle on pretty much everything from mild acceleration up. The whistle is just gas moving through a small gap like when you whistle.

When everything gets nice and warm the expansion of the manifold, gasket and head pulls everything more or less into position again and the whistle under normal circumstances drops. Then you put your foot on the loud pedal, make more exhaust gas, spool the turbo up which among other things places a bit of a restriction on the flow of the exhaust gasses which causes the exhaust manifold pressure to rise. This increase in pressure will now force the exhaust gas out the little holes that remain or deform the gasket enough to open a gap through which the exhuast gas whistle through on their way back to the atmosphere.

Heres the bad news ,ITs not going to get any better and if you ignore it long enough the potential exists for the gasses to scoure away the mating face of the parts. untill it gets fixed I would suggest driving very gently to minimise the loading on the exhaust.

There are some field mods that can be made to the exhaust system to make it significantly less likely that there will be a recourance of the problem but you probably wont be able to get them done under warrenty and will have to fork out for them.

Excellent info gents and yes BlkKnight, that

First thing in the morning when you jump in and fire up everything is cold and the gaps that might exist are at their widest so it will whistle on pretty much everything from mild acceleration up. The whistle is just gas moving through a small gap like when you whistle.

When everything gets nice and warm the expansion of the manifold, gasket and head pulls everything more or less into position again and the whistle under normal circumstances drops. Then you put your foot on the loud pedal, make more exhaust gas, spool the turbo up which among other things places a bit of a restriction on the flow of the exhaust gasses which causes the exhaust manifold pressure to rise. This increase in pressure will now force the exhaust gas out the little holes that remain or deform the gasket enough to open a gap through which the exhuast gas whistle through on their way back to the atmosphere.

is exactly what I am talking about. On the way to an appt this morning, in traffic, it was very noticeable. On the way back, I could hardly hear it...if at all. I will get the dealer to attend to tomorrow along with aircon not working properly...plus I did get a 3 yr warranty with the vehicle as back up...glad I asked about the whistling. Much appreciated the feedback,

Regards

Stevo

Stevo, check the Double Cardan joint on the front drive shaft also, mine was near to failing recently and made a noise only on acceleration that would best be described as similar to crickets chirping I origionally thought it was my serpentine belt slipping or perhaps one of the belt pulley's and only checked the Cardan Joint by chance. Anyway, best to get it checked properly as if it fails while driving you'll be in a spot of bother.

Cheers, Phill

Thanks Phil, will do, and crickets chirping would be a good explanation of the sound. Also I have no tech expertise so me checking anything would be a recipe for disaster . Now a question, hopefully answered before I go to the dealers tomorrow, I just got home and with the vehicle in park, popped the bonnet and touched on the accelerator to see if I could hear the noise...no noise. Though on the way up the road driving, I could hear the noise. Does the possible explanations only occur when the car is moving and accelerating? Thanks again for the info,

Regards

Stevo