Would a frozen wastegate linakage cause high EGT? And if it does, what damage does it do to the turbo?

I ask because I have to rebuild my turbo (excessive side to side play). During inspection/removal I've foung the wastagate linkage rusted fast. Truck came from NY east of lake Erie. '99 2nd gen w/ only 106K. Lift pump replaced w/ in-tank pump, IP is remanufactured. Judging by rusted/non-rusted bolts/nuts the turbo may have already been worked on.

Also, I'm a little confused on the clamp plate for the turbo housing. Mine only has 4 cap screws and Cummins rebuild buliten shows 6. What's up?

I'm fairly new to CDT and have a lot to learn. I read a lot of threads just so I don't have to ask something that's already been answered. Hopefuly, I'm not doing that now.

 

As long as the wastegate is frozen shut, your EGT's will be cooler if anything because it will be making more boost. If the wastegate is frozen open, then you will definately be low on power with high exhaust temperatures, and excessive smoke. If your truck is an automatic, then you will have the smaller turbo with a 9cm exhaust housing instead of the standard stick shift HX35 with a 12cm exhaust housing. The automatic turbo(HY-9) might have less bolts holding it together than the standard HX35. Hope this helps a little

Eric

 

This helps a lot. Real good explanation of turbo too. I really don't know how to determine which direction the wastegate is frozen. This is my first CTD so I don't know the "feel" of the power (yet). The turbo is HX35W. No smoke, but I wouldn't hold my hand near the exhaust tip for more than a few seconds.

Why such a smaller housing? 12 Vs 9 equates to 44% less area! Now I know why more people choose the 5/6 speed.

Would the wastegate issue cause premature turbo failure? Because that's what I have. I can move compressor wheel side to side and just barely touch the housing, but didn't touch when running (no marks).

 

Well it seems to me that it would be almost impossible for the wastegate to stick open, so i really dont think that should be a problemfor you. And like i said, If it is stuck shut it wont create problems anyway unless you increase the power a lot, and it is making over 35psi of boost. A stock truck would do good to make 25psi with a wastegate that is stuck closed. No smoke should mean that the turbo is working fine. A used turbo will have some side to side play. You shouldnt be able to make it touch the housing, but id say as long as it isnt touching while the truck is running you are fine. The smaller housing helps to spool the turbo faster, and with the automatic that is a little more important than the 5/6 speed. Faster spoolup also means less smoke, so it was also an emissions thing as to why they put the 9cm housing on the automatic. Only certain year automatic trucks had the 9cm housing though(the later years of the 24 valve), and if your turbo is the HX35w, then you have the better turbo. The one with the 12cm housing. I have the HX35w on mine, and i dont know why i didnt think of it when i responded the first time, but mine only has 4 bolts holding the exhaust housing on too. Hope this stuff helps a little. Let me know if ya have anymore questions, and if you really need to know if the wastegate linkage is stuck open or closed, unbolt the backing plate off the turbo(what the downpipe connects to), and there is a flap connected to the wastegate linkage that will then be visible, and you will be able to see if it is open or closed when ya get that off. Thats the simplest way to tell if it is stuck open or closed.

Eric

 

I think the truck would throw a code if it was seeing excessive boost wouldnt it?It would defuel if he was making more boost than normal,but he has no fuel mods so i doubt it

 

The first time I dynoed my truck, it was on HRVP and Jammer2 sticks alone, no tuner or anything. Hit 300hp, 35psi, and it never defueled or threw a code.

 

hmmmmmmm maybe the 00-02 are different?