Hey guys, newbie with a 1992 300D 2.5, and a 1987 300D, both w124. I've got a spare KKK turbo for the '87 and a garrett for the '92. I'd like to give rebuilding them a try. The '87 got a fresh turbo less than 40k ago, but keeping a spare on the shelf is always nice, the '92 I just picked up and I don't know much about, it may need a turbo. So I wanted to experiment on the '87 turbo and if all goes well, rebuild my '92 turbo.

Is the KKK on the '87 a K03? I've done some research on rebuild kits, some come with new bolts and cost around $90, others are just bearings and seals and are like $50. Do I want new bolts? I talked to a Kamak sales rep, they list a K03/K04 rebuild kit for $70.

I'll be post more and more in the future. The 87 is shifting like a dump truck, but the trans only has 40k on it. From what I have been reading things are pointing to a vacuum issue, the car isn't up here right now, but when it is I will work on that problem.

The bottom of the fuel cap has rust on it and the other day we found water droplets on it. The car idles rough, but runs smooth as glass and gets 30mpg on the highway. I presume there is rust in the tank and we're getting a low RPM miss because of crap in the injectors. Is this a common issue? Moisture in the tank? Is there some seal that fails? My plan is to pull the tank and seal it, then put in the new injector nozzles sitting on the shelf.

After that I'd like to pursue some mpg and performance mods. Is the OM603 worth messing with? Anything I need to know? I don't want to run 9s, but 9s to 60 could be nice (basing that off of the 10.8 stock figure I found).

Thanks!

 

Some backround: Back in the late 1970s I worked in a Fuel Injection Shop. One of the other things we did was rebuild Turbos (mostly for the Big Rigs).
What I have see missing from all of the threads and posts I have read so far concerning rebuilding Turbochargers is the specifications.

I have see no Max bearing Bore Sizes, no minimum Turbine shaft sizes, no Turbine Sealing (piston type ring seal) Groove/Land limits. And, not even what the Shaft Nut is supposed to be torqued to. (And, way less info for the KKK Turbos.)

People are just installing standard sized bearings and seals. Some have enought sense to have the Shaft and Wheel Assembly balanced. But, no one seams to be measuring any clearances and so on.

It could be that the Turbo on a Mercedes just does not take the beating a Turbo on a Truck gets and they do not have much wear on them;allowing them to be re-bearinged and re-seald.

But, not enough members of any of the Forums rebuild there Turbos to get any sort of stats.
If there Turbo leaks most just go to the Junkyard and get another Turbo; and apparently there is a high success rate doing that.

 

i have a couple turbo questions myself. i have a 1990 2.5 turbo that i just purchased and i wanted to see if a k04 turbo would work on that motor without having to replace injectors, and if i would make a noticable difference. could someone help me out with this?

 

then what could i do to make it a little bit quicker. i already have plans to make some sort of cone like air intake, as well as a straight 2.5" pipe with a flowmaster muffler. i was wondering if the injectors out of a w140 diesel would make a difference, or if i could reprogram the ecu somehow, i haven't figured that part out yet. what do you guys think?

 

thanks for your help, i'm probably being a pain in the ***, but what about the turbo that you have on your car, could i do something like that, possibly a front mout intercooler???? i really don't know how to hook up diesels. i have a supercharged VR6 and that easy to make fast, you just gotta have money. thanks again for your help,

 

one more thing...you said that the ecu controls boost pressure, what if i up the boost? and how can i do that? would the stock turbo be able to handle it? as well as the gaskets and manifolds?

 

Sorry threads suck when the op falls off the planet. The 92 is running good, so it may not need a turbo soon. I still need to track down why the 87 is shifting bad but I've been too busy to work on it. I ordered all the seals to the tank from mercedes and a tank resealing kit from kbs.

 

hey forcedinduction thanks for all your help. i went to https://mercedesforum.com/forum/diesel-performance-49/ and that's a great forum, but i seem to get all the answer from you here. so now what can i do to the injection pump to produce more power or do i have to get a bigger pump? also torque? i feel like not enough people are talking about torque? it's what makes diesels move. how do i up my torque?

 

i may sound like an idiot, but what is a VNT turbo, where can i get one, and how much do they go for? also what's the difference?

i started a new thread on under " how do i make my w124 faster?" i look forward to your posts there.