Testing and Adjusting Turbo Charger Waste Gate Assembly

A faulty 617 turbo diesel waste gate can really affect engine performance

So what is the waste gate for?  Where is it located? Do I have to do anything with it or be concerned about servicing it? What does it "waste"? It literally "dumps" excess boost pressure back into the exhaust by opening a valve when the intake pressure reaches pre-set limits. This prevents damage to the engine by limiting the amount of "boost" intake air pressure that can enter the combustion chamber. The waste gate on the Garrett T3 turbo is located on the bottom of the turbo. 

Problem & Solution

Common among these chassis:


Correct boost pressure is essential for both engine health and performance. Too much boost pressure can overheat and damage the pistons. Too little and your engine will not perform up to its potential. It may even feel like you are dragging an anchor behind the car when driving down the road. As these engines age they will develop problems. Most common are a torn diaphram or a stuck open or closed valve. Working on them can be challenging.

Here is a recent email we received from a customer: 

Year: 1985
Model: 300td
Product Description: wastegate and turbo
"I have adjusted the waste gate with 3 full turns and am having a difficult time getting the spring in place over the waste gate cover. I would also like to remove the turbo and inspect it. It needs to have the lowest bolt next to the engine and the two bolts holding it in place underneath the turbo. I have no idea which tools to use on these trouble spots. If I buy the turbo removal kit I will have a better chance of getting the circular spring back on the waste gate. I would like to know if you have any tips on getting that stubborn spring back on once the turbo is off and can you throw that in with the cost of the repair manual. The waste gate had a lot of carbon in it and leaked some oil. The turbo may be leaking some oil but not sure."

We offer a kit that will explain how to take the waste gate assembly apart (including tips to get that spring removed), how to inspect it and how to adjust it properly. It should not be messed with or adjusted without attaching a pressure gauge to the engine. This kit is called the "617 Diesel Turbocharger Boost Pressure Test and Tuning Kit" and is listed in the related products you see here.

If you want to remove the turbo from the manifolds for inspection, cleaning or overhaul we do offer a special tool kit that Kent designed to get to those hard to reach bolts.