Sixto,

Those pics are fabulous. Thanks. Couple of questions...

1. Are you saying that I can disconnect the rod at the wastegate and turn it in (CW?) on the controller to tighten it? I believe there is a locking nut inside the diaphragm that may prevent this...

2. Should the wastegate controller move easily? I can move it only by boosting the diaphragm. I have not yet tried to disconnect it.

3. It's hard to tell from your pic... but it looks like the position of the wastegate controller rod attachment at the wastegate on your cleaned turbo is slightly closer to the diaphragm than mine. Mine is turned slightly left of perpendicular while yours looks slightly right. Based on the pic this would make a huge diff in flapper position. Perhaps this is just a spring problem.

I'll try adjusting the gate first and then I'll disconnect the downpipe from the turbo if that does not work.

4. If the problem is not the spring or exhaust I'm guessing the wastegate is gunked and not closing would be the next likely culprit?

5. How much of the turbo needs to be removed to get to that section to clean it?

Thanks for your post. I think this will help a lot.

Hugh

Those pictures are just to provide a visual. I don't think either of those are MB Diesel applications.

1) I don't know about the KKK turbo which came on some 603s but the Garrett actuator rod is threaded onto the actuator an inch or so from the actuator body. I don't see a locknut on either of my cars, just a nut to spin the rod. If necessary, gently clamp the threaded stub on the actuator then turn the rod.

2) Sounds like you have a healthy actuator or at least a healthy return spring. It takes a lot of force to move the rod by hand.

3) As mentioned, I don't think that's a MB application. All T3's are similar, though. The 603.96 application would have that image rotated 90* CCW and the wastegate flap shaft would be rotated 60* CW. The lever arm would also be oriented differently but I've lost my spatial orientation.

4) I've never seen a gunked wastegate flap. I've seen a misaligned flap.

5) It's a sucky job but I think you can remove the downpipe, remove the two brackets attaching the aft section of the turbo to the manifold, then remove the wastegate housing from the turbine section.

At the end of all this, the turbo might not be your problem. The ex-Jeremy '87 300D currently in my driveway has a recent turbo and cat courtesy of a trap recall. It didn't resolve a midrange bog in high gear. My other '87 is a bit of a slug off the line but boost is all in by 2200 rpm in any gear. The other car will run rings around this car (and leave smoke to prove it).

Sixto
87 300D^2

Sixto,

Thanks for your help so far. I disconnected the rod from the wastegate. Wastegate moved easily but did not feel like what looks like some sort of high heat gasketty type material. From the pics it looked like closing the wastegate should feel a little squishy. That was not at all the case. Was more of a metallic type close. I wired the wastegate shut. Not much difference from where the actuator put it. No real change there (maybe .1 extra to 2.1 psi). When the car cools down I'll try disconnecting the downpipe from the turbo. I'll also see if I can find that adjustment you're talking about.

Some more questions...

1. If the downpipe does not work I'm thinking the next step is to pull the turbo?
2. Or should I try removing the ALDA first (obviously simpler)?
3a. If I remove the ALDA I'm guessing I should run the line from the SO directly to the other contraption that looks exactly like it? (There is a Y from the ALDA back to that guy.)
3b. Or is it safe to just run a line from the manifold to that one?
4. What size is that clip that holds the rod to the wastegate? I pulled it with a magnet but then dropped it in my lawn.

Thanks,
Hugh

Gasket material? The wastegate flap is a thick metal disk. It's not a hermetic seal. Think manhole cover.

1) Could still be a fuel problem. Maybe even an IP timer that isn't advancing as it should.

2) I'm surprised you haven't done so already. I'm not saying take it out for good. I'm only saying take it out as a diagnostic step.

3a) The ALDA boost signal is shared by the transmission amplifier. Keep that in place or shift quality will get goofy. Just plug the ALDA line for now.

3b) You can do that.

4) Take your calipers to the wastegate flap shaft :/

Before you pull the turbo, check simpler things like the fuel tank vent and strainer.

Sixto
87 300D^2

Sixto,

Thanks again for the awesome help. I'm brand new to working on this car.

Popped the ALDA (though it tested ok on the car). Boost went up 1/2-3/4lb and a bit more performance. Smoked intolerably for city living. Plugged the Y going to the ALDA to make the other things work right.

I'm thinking now exhaust over fuel problem. Without the ALDA it was dumping a lot of extra fuel into the mix which was going out the tailpipe. I did not consider IP/timing issues as the engine runs very smoothly. Perhaps that's a mistake on my part. I will have to do a bit of research on that one.

More Questions...

1. It's my understanding that the timing chain can stretch and the IP can be adjusted rather easily for that?
2. Fuel strainer looks pretty easy to pull with a large wrench? I should have done that already!!
3. Where is the vent?

Happy to not be pulling the turbo just yet. Tomorrow I'll try disconnecting the exhaust from the turbo, check the screen and clean the vent.

Thanks for your help,
Hugh

1) Chain stretch or elongation is eyeballed by setting the cam to #1 TDC then reading the position of the crank pulley. I forget the spec but something like 5*ATDC is the point at which you should roll in a new chain. Offset keys aren't available for the 603 as they are for the 617.

2) Consider that the strainer is all there is between all the fuel in the tank and your face. It takes a 46mm wrench.

3) Heck if I know I've never dealt with it. Rather than mess with the vent, drive around with the fuel cap off (when the fuel level is low) and see if there's any performance improvement.

Sixto
87 300D^2

Sixto,

Tank is kinda full. Could one assume the strainer is relatively clear by pulling the line and getting flow? I'd like to keep my face a little clean...

Cheers,
Hugh

I'm leaning toward this as the problem as well. The chances of the wastegate being the issue are slim. They are a very basic contraption that operate for the life of the turbo with little issues.

Although the ALDA removal indicates the presence of too much fuel off idle, as would be expected, the real question is the available fuel under load at high rpm. I might want to see fuel pressure readings under load to be sure the pump is providing adequate amount.

There is a spec for fuel quantity during cranking over a 30 second time interval which can be utilized for a quick determination of available fuel quantity. This would be a valuable check and would verify the strainer and the fuel pump simultaneously, without the need to rig a fuel pressure gauge into the cabin.

If this proves to be adequate, the function of the timer must be investigated next.

Brian,

Thanks for jumping in. Disconnecting the exhaust from the turbo solved the problem to 6 psi with a lot more lag. I suspect fuel issues would jump things to 10.

I'm looking for a 46mm wrench to get the strainer out.

A question...

1. I assume that to test flow as you're talking about I could jump a fuel line off the pump and just see how much goes into a bucket while cranking the starter for 30s? Is that how you would do that test?

Thanks,
Hugh

I'm home now and checked the spec.

You need a minimum of 5 ounces of fuel coming back through the return line in 30 seconds of cranking. If not, you've got fuel problems.

Naturally, you'll have to hold the fuel shutoff manually so it won't start.

Don't bother. The wrench is way too big for the space, and, without some offset, it won't work anyway.

Get a 1 13/16" socket (it will be 3/4 drive).

You won't be able to use a socket wrench on it (if you even have 3/4) because of the half shaft. Just drive it with a pipe wrench. There isn't much force holding it in place.

Be a bit careful with the socket, however. Some have a huge chamfer on the ID and most of the available length to drive the nut is lost. The nut is very short............on the order of 4mm or so.


You can also get lucky and remove the strainer by putting a wrench on the hose fitting that attaches to the strainer. Many times, the strainer will turn before the hose fitting. Of course, you'd need to remove the opposite end of the hose from the hardline before attempting this.

Whatever you do.............all the fuel in the tank must be drained into a container via the supply line before removing the strainer. Kerry likes to run the return line into a container, start the engine, and sit back and relax while the tank is drained. It's the gentleman's way to do the job.

Sixto,

Again thanks for keeping me from pulling the turbo!!!

Q:
Without the exhaust connected to the back of the turbo I can hear it spool down. I'm hoping that's normal?

Thanks again,
Hugh

To eliminate it from your checklist remove the alda pot and test the boost, If it increases dramatically there is something wrong with your alda. easy to check and definitive. Cheers Dan

__________________
It's always something simple
91 300D 603.960 (from japan) 194K
92 Toyota Diesel Landcruiser HDJ81-t 116K
02 Golf TDI new head courtesy of PO
87 300D
97 BMW 525 TDS Wagon 5spd
bunch of Onan and other diesel generators