All right, here goes... I know its little farfetched when it's about engine sounds/noises, but here goes

Been hearing it for the last 2 or 3 weeks. The "whirring" starts to appear from 1700 RMP on, in any gear.. and it's loudest around 2-2300.. (tried to take a video before work today, but its hard to notice it.. will try again). It's hard to explain the noise, tried to locate it, but no luck... When it's stationary, no whirring whatsoever (so far).

It can be heard while driving in neutral, or with the clutch down (again, at those RPM's).

The truck doesn't appear to be losing any power. Although, the whirring/buzzing gets 'louder' under more weight.

Ok, that's all I could think of.

Any ideas where should I look, so I can check it out myself first - when I get some free time (over weekend), in case it's a DIY job.

Thnx!

does it sound like a boost leak then?

belts rubbing, cooling fan rubbing, power steering pump. intercooler fan, just throwing anything out there that could make a noise.

Thanks, guys..
Anything helps ... a mech nearby my work place looked at it and said "...best wait till it gets worse and louder so we can find the cause" ...so yeah, any ideas you guys have will help when I finally get under the hood to pinpoint the culprit..

Little update; the whirring sound from the engine turned out to be a snapped balance belt.

Truck's at the garage as we speak, and I decided to do a few scheduled and unscheduled repairs:

• New Balance belt
• Ne big / timing belt
• Timing & balance belt tensioners
• Alternator belt
• Power steering pump belt
• Water pump
• Thermostat
• Valve cover gasket + tuning of the valves
• And all the tiny bits & pieces that come with it; seals etc.

Last 'mechanic' mounted the alternator off for a few degrees, & that put some extra tension of belts & pulleys.. That gonna get fixed.

Next,
• New Electromagnetic turbine valves + tuning - the max pressure should be 1.2 - 1.3 max, mine was up to 2.4, hence the sluggish pulling after 3000 rpm (and overboost errors).

• Inner boots/cuffs
• Bits & bobs around front axle and steering parts
• New transmission bracket
• Brakes / Brake pads

• New Crankcase (was leaking, someone tried to weld it before but it started to leak again.
• All new alternator mount + oil pump

+ all the classic service bits, all liquids + filters

..etc. etc. I prob forgot to mention a few.

The inspection lasted for 2+ hours, he examined it to the very last inch..

Oh, and he just finished working on one of the trucks while I was over, so we did some testing... man, what a difference when everything is tuned right in these truck.



Total cost ~ 1.300 Ł ...but at least the truck will FINALLY be in great condition, after all those years. Cant wait to get it back.

A new crank case