High pitch whistle or squeek when cruising

[Johnbrooks]

Does anybody know what would cause a squeek or whistle when cruising, with associated small lose of power (it won't go into overdrive) and very large increase in fuel consumption.No alarms come up on dash and it seems to be starting and running allmost normally.

 

[nakedape]

Have a look at all your induction/ boost pipes/ hoses for leaks.

 

[Old.Tony]

What he said.

Leaks should be visible by a small amount of oil coming from the charge air system (which refers to anything between the turbocharger and the intake manifold).

 

[sparra04]

check for a vacuim hose with a hole,perished,disconected?
good luck
wastegate working or stuck open?

 

[Johnbrooks]

HI guys, thanks for the input, I've checked all hoses for leakes,holes ect can find nothing. It is reluctant to go into OD. Somebody said it could be the exhaust manifold gasket, nots sure about this, surely there would be black soot around the engine bay.At Coober Bedy and may have to travel straight to Alice to the Nissan man. Its much worse while towing the Van.

 

[Old.Tony]

You're right about the gasket - you will see black soot from around any leak.

If your car is stopped, in neutral and you press the accelerator so that the engine RPM rises to around 2,000rpm and you let it fall again (repeat over and over) your turbo will be producing boost and you should hear the squeal.

So, while you've got someone pushing the pedal for you, lift the bonnet and listen around the engine bay for the squeal.

If it's not squealing then, it's possibly not the turbo or charge air lines at all. Drive for about 5km and pull over. How hot are the wheel nuts? You could have a dragging brake?

If it IS squealing and it's coming from the turbocharger, it's possible that the bearings in the turbo are letting go and the next step is fragmentation of the impeller (equals turbo destruction). Not sure I'd want to be stuck between Coober Pedy and Alice without the turbo operational - that's not only a big tow, but it's going to use gobs of fuel to let you maintain any sort of speed.

If the turbocharger HAS let go, you should look for the cause. If you're in the habit of treating the diesel just like a petrol engine and just switching off when you're done, this is probably the answer - a hot turbo cooks the oil in its bearings with the inevitable hard deposits causing bearing (and turbo) destruction. It could also just be old, maybe the oils used weren't up to being pumped through a hot turbo. Maybe the water coolant lines into the turbocharger aren't flowing 100% - there could be a number of reasons.

Hope it's not too expensive for you - a boost leak is the cheapest and most common cause, which is why it was suggested first.

 

[Pete22]

HI guys, thanks for the input, I've checked all hoses for leakes,holes ect can find nothing. It is reluctant to go into OD. Somebody said it could be the exhaust manifold gasket, nots sure about this, surely there would be black soot around the engine bay.At Coober Bedy and may have to travel straight to Alice to the Nissan man. Its much worse while towing the Van.

Make sure you keep an eye on any work done by Kittles Nissan in Alice....they don't have the most robust of reputations.