"Daddy, it sounds like a choo-choo train!"

[Floundered]

The kids were bang-on. A test drive with our recently purchased '03 Excursion 6.0l PSD and the 5000lb travel trailer on the highway produced a fast and loud "choo-choo-choo" from the engine at 2500-3000rpm when accelerating or working uphill. About 2 choo's per second. At the same time as the noise I noticed a loss in power, though the truck could still accelerate. No engine warning light. No boost gauge, so I couldn't tell what was going on there. Doesn't happen drivign around town or gently driving on the highway without the trailer.

Wastegate gone nuts? Some kindof backpressure sensor complaining about it's job?

Still under engine warranty, but some ideas would be nice before seeing the dealer.

Thanks!

[harald@bd]

What you are experiencing is the VGT veins in the turbo fluttering.they do not like to function under light load ,if you kick it down it will go away. Ford considers is normal for the VGT turbo.The loss of power when this happens is from loss of boost pressure as the turbo releaves itself with the flutter.
Basically ,the veins open and close quickly causing the noise.
Let it rev up and you will not have this issue.

[Jon]

That is the kind of answer I like. I wish we could get an answer like that from the engineers!

[Floundered]

Originally Posted by harald@bd

they do not like to function under light load

What is considered a light load? The loud choo's only happened when going uphill or accelerating while pulling the 5000lb TT. Never happened at constant speed on a flat stretch of road or when driving just the truck around town. I suspect it would happen the whole way up the Coquihalla Highway. (That's "Koe-kih-HAL-ah, a long mountain highway, to the non-BC'ers.)

Originally Posted by harald@bd

if you kick it down it will go away

What do you mean by "kick it down"? Stomp the accelerator pedal or bring down the RPM's? Accelerating through the noise brings the engine to normal again at over 3000rpm, as does backing off the accelerator to either shift up to the next gear or just slow down to under 2500rpm.

Originally Posted by harald@bd

Ford considers this normal for the VGT turbo.

Now why doesn't that surprise me, even though this is the first Ford I've ever owned? But the noise and truck hesitation/lurching with each "choo" seems too severe to be normal vane flutter or adjustment, although the sound of the "choo" seems to match something turbo-related like that.

Thanks for the reply Harald!

[Jon]

Some people say its normal, but I don't like it. When one comes in doing that we replace the turbo. As long as it is for sure the veins sticking.

[gcop]

Are you towing with OD on or off?

[harald@bd]

I too drive the Coq a lot,I just recently moved fromkamloops to kelowna,So I know the hill you are talking about. My 05 only creates this condition when lugging up hills when empty.But will do it when my trailer is on anytime but only lugging it.That engine and turbo are designed to rev.Kicking it down means having it drop to a lower gear .Don't be afaid to run that truck it's made for it.

[Banshee34]

My first thought was the overdrive as well....

[harald@bd]

This is definetely a turbo issue,the transmission has nothing to do with the noise he is referring to.

[Banshee34]

Originally Posted by harald@bd

This is definetely a turbo issue,the transmission has nothing to do with the noise he is referring to.

Sorry Harald.... you had mentioned lugging it uphill and I assumed overdrive was on.... that's why I asked about the overdrive... Still learning ya know! Any knowledge is greatly appreciated!