A buddy of mine brought his truck to me yesterday and said that he noticed his turbocharger had stopped "whistling" even under heavy load. It's a 93 F350 with the 7.3L International Diesel V-8. So first things first, we covered all the basics: clean the air filter, lube oil and filter change, fuel filter change, coolant flush and fill, and a good under hood cleaning. I know most of these things don't have anything to do with the turbo, but the maintenance had been neglected. With the intake plenum off, we did a quick inspection of the turbo. The compressor blades looks good. They spun freely and there was no indicated contact with the inside of the compressor housing. After all of the work, we took it for a ride. Right away he noticed a dramatic performance increase, but I suspect it was due to the new fuel filter. The old was was completely clogged with crud and bio-growth. I took it to a few hills around town to load up the engine, but still zero turbo noise. I'm thinking that the wastegate may be stuck fully open, but wanted to check here before pulling it off. Has anyone else had this issue? Also, does anybody know a good aftermarket retailer for performance parts for the 7.3L International? Thanks in advance. <!-- / message --> <!-- BEGIN TEMPLATE: ad_showthread_firstpost_sig --> <!-- END TEMPLATE: ad_showthread_firstpost_sig --> <!-- controls -->

 

Before I did anything I would rig up a boost pressure gauge to see how much boost the turbo is making.

IDI turbos don't whistle like the newer turbos do.
The engines can't handle the higher boost pressures since the base compression ratio is higher in the IDI engine.

I would say the increase in performance was a combination of fuel filter and air filter.

Does the truck still have a muffler on it?

 

Yeah, I'm sure the air filter helped too. The truck still has all the stock exhaust hardware, muffler included. I'd love to install a new kit with a better downpipe and freer flowing muffler. Maybe I should misplace the catalytic converter too.

 

No catalytic converter on diesels unless it was manufactured for California or it is an 05 or newer truck.

I would remove the muffler and upgrade the pipe size to 3".
The down pipe also kills the turbo, the size is to small and it is smashed flat on top of that.



ATS left, stock Ford right

But the turbo outlet flange is also much bigger on the ATS turbo.



Again ATS left and stock Ford right.

Ford used the ATS turbo system, but they re-engineered it to increase the clearance between the firewall and down pipe.
A cab seam has to be folded over for the ATS downpipe to fit, not something the factory would be wanting to do.

 

I would check to see if the wastegate actuator arm clip did not fall off the wastegate. this happened to me in mid tow, before I new much about these trucks. it took me a while to figure it out, but i found it.

I just reconnected the wastegate actuator arm to the wastegate and wha-la, it was fixed.