my buddys 1991 2wd ctd with 727 auto, and on are way back from utah out of the the blue this loud squealing (sounded like air being let out of a baloon) started sounding and the pitch increased with how hard i pushed the peddle, the noise only sounded when the truck was under load and at hard throttle, like when we hit hills, i came from the driverside, im thinking its a tiny vaccum leak but don't know, anyone have any ideas??? thanks


jason

 

Jason it sounds a lot like you may have found a small hole in one of the intercooler boots.
Check them closely especially around the drivers side as it seems the trans cooler line clamps may worry a hole on occasion if they get close enough. Make sure all the hose clamps have at least a quarter of an inch of hose sticking out past them to clamp good.

Stuff like that. The intercooler itself is suspect as well.

Hope this helps.

David

 

intercooling system. Mine did the same thing, when I wrapped the hole in duct tape, n blew a hole through that. Check yer boots.

 

ooops i didn't specify, my bad, its my buddys truck, but it is the non ic model, so with that do yall have any other ideas, there isn't any difference in how it runs at all, it just squeals underload or harder acceleration between 40mph and up, but if you slowly accel up to highway speeds it wont squeal.


jason

 

Like everybody else said, you most likely have a boost leak. An exhaust leak before the turbo can also cause a squeal.

 

well i guess this weekend my buddy and i will check all seals and tighten everything to be sure thanks


jason

 

Mine had a squeal but it was the middle u-joint on my driveline...

 

Wouldn't hurt to replace the serpentine belt. Mine had a nasty squeal under load.

 

Check the little steel line that feeds the AFC housing boost from the intake. I played with my timing one too many times and that line cracked. I chased that whistle for a week

 

Also check the belt tensioner.. The idler bearing some times get noisey...