Wastegate actuator broken....what did it mess up?

[woodstockva]

While working on my 93 7.3 IDI Turbo this afternoon, I noticed that the wastegate actuator was NOT opening the wastegate at any rpm (idle-full throttle) & the wastegate arm looked very rusty. I sprayed it with liquid wrench & tried to move it by hand (with the actuator still hooked up & engine off), nothing would budge even 1/100th of an inch. I then took the clip off that holds the actuator arm to the wastegate arm & attempted to remove the two....still no luck....in my struggle I snapped the actuator arm in half & the wastegate immediately moved forward (toward the firewall). It moves very freely inside the turbo & has no "sticking" at all.

So....besides needing another actuator, what problems can I expect to run into in the future from this?

From what I have read so far, with the wastegate completely closed, no boost pressure was escaping & all exhaust gases have been routing themselves through the fins in the turbo? Is there a semi-easy way to test my turbo prior to buying another wastegate actuator to see if the turbo is still any good?

I do not have any aftermarket gauges installed w/the exception of the factory oil pressure mod (actual sending unit & bypassed resistor on gauge panel). My oil pressure is very good, the truck has not overheated, no leaks that I can really see are active....hopefully I got lucky. I have owned it for 1 year, and put approx 3000 miles on it in that time. I do not know how long this problem has been going on & I have never checked it until today & I do not know if it was broken before I got the truck.

The only performance issue I have noticed is when I am going up long steep grades in 3rd gear while pulling a loaded car trailer.....it does occasionally loose 50% power in chugs (aka....30mph.....chug chug.....20 mph......back to 30mph)....not really sure how to describe it other than it seemed like a lack of fuel. Then it gets back to speed. (Also, this happened BEFORE I did any fuel system maintenance....injectors, lift pump, fuel leaks, etc).

Could the closed wastegate be related to my super rough idle/miss that I made a video about?

Thanks (ahead of time)!

Woodstockva

 

[icanfixall]

Wel you now have no way for the excess boost to bleed off and not over run the turbo. The exhaust gas will apply pressure inside the hot wheel area and keep the wastegate closed. Not good at all really. Now if you install a boost gauge you can run without a wastgate forever but watch the pressure. Limit it to no more than 12 to 14 lbs and the heads will stay on.e

 

[typ4]

the wastegate will flop around and just bypass, you likely willl have no boost. if it was stuck shut you may have burnt turbine wheel tips.

 

[woodstockva]

Update :

I removed the wastegate actuator today & pressurized it with shop air & it opened fine. I need to still test the actual pressure it is opening at, but it appears to be working now. Also, I was able to find an "adjustable 3" long wastegate actuator arm end" on ebay for $6.29 w/free shipping. I checked the threads on the new part & simply used a tap & die set to recut the threads on the existing arm to match. So hopefully early next week I will be back on the road.

One thing I noticed when pulling the actuator was that the supply tube from the turbo to the actuator (that pressurizes to open it) was loose & would easily twist & move with my hand.....not only the little red rubber line, but also where the brass nut attaches to the fitting on the turbo. There is a small rubber oring under it that was in very bad condition & it definitely was leaking pressure. I am not sure honestly if my truck had been making enough boost due to that leak in order to open the actuator.

When I reconnect the actuator, can I put a "t" in the rubber section that connects the metal tube to the actuator & run a pressure/vacuum gauge to it? What boost pressure at what rpms should I be looking for?

Thanks a lot!

Woodstockva