Hissing/squealing Turbo Toyoto 100 series FTE

I had an identical noise the other day, it was a leak at the inlet manifold.

We tightened the studs and no more noise.

While your at it check all the hoses and fittings to the turbo and intercooler

Syd

Check the hoses after the turbo to the intercooler, and from the intercooler to the inlet manifold for splits in same.

I have a KJ JEEP that over the past 6 years has incurred a split in both of these hoses and the noises that it made covered all of the above that you describe and some.

DD

G/Day Syd

I recently had a problem with the EGR Valve Gaskets leaking on our Patrol, had the same symptoms as you are describing.

Cheers

The sprung flange from the dumppipe to exhaust can leak if the cat converter gets blocked with carbon. Had it happen to mine - sound comes on at the same revs but was louder than what you are describing. Worth looking for signs of soot around this flange. The solution is to upgrade the exhaust to a 3" without a cat converter.

Recently had a similar problem with a whistle from about 2500rpm under load in our 100 TD. Thought it must be a leak but couldn't find it. I was a bit embarrassed when I took it to a mechanic who said "it's in the snorkel" then proceeded to take out the air filter to find a bloody great wasp nest in the bottom of the snorkel. Cleaned it out, new filter and no noise!!