Wastegate actuator swap for OM602.962? - Page 20 - PeachParts Mercedes-Benz Forum

Diesel Wannabe · #1 09-19-2012, 09:37 AM

I'm new to MB diesels and loved this thread, thought it would be my first project for my 92 300D. Now I guess I am in waiting mode for an alternative to the now discontinued actuator. Any other solutions that I missed?

JamesDean · #2 09-19-2012, 10:43 AM

My ebay alternative unit arrived last week. I've not had a change to install it or anything.

I plan on working on the transmission this weekend and trying to get all that fixed again... After that I'll try the turbo and see.

I originally wanted to build a test bed of sorts to see how exactly this thing operated..

shertex · #3 09-19-2012, 10:56 AM

Quote:

Originally Posted by JamesDean

My ebay alternative unit arrived last week. I've not had a change to install it or anything.

I plan on working on the transmission this weekend and trying to get all that fixed again... After that I'll try the turbo and see.

I originally wanted to build a test bed of sorts to see how exactly this thing operated..

Kris, what was the exact part you got? We'll all be interested to see how it works.

JamesDean · #4 09-19-2012, 11:10 AM

Quote:

Originally Posted by shertex

Kris, what was the exact part you got? We'll all be interested to see how it works.

Thats it below:

T25 T28 GT28 Turbo Internal Wastegate Actuator Nissan | eBay

Its for a T25 turbo which I think it the turbo ON the 300D 2.5... The only question left remaining is pressures.

If I can't get the pressure correct, at 14-15 psi, I'll get one of these:

TurboLogic Performance (TM) Model TL-21 MBC : BoostController.com LLC - America's Source for High quality turbo boost controllers, silicone hose, and more performance products - 877-836-6155- precision boost control. Turbosmart Warehouse Distributor

And be done with it.

Total Cost with Controller = $40 + 56 = $96 same as the original actuator at the start of this thread.

JamesDean · #5 09-22-2012, 12:13 PM

I got some time to play with the new actuator I bought from eBay.

I hooked it up to my air compressor and attempted to set the output PSI using a tire pressure gauge. I think I was able to set it to about 6-7 PSI. I hooked my blow-off gun to the actuator and the actuator moved when I triggered the gun.

They said you could adjust the rod and achieve different results. That must be done on the car..

IF we can adjust that rod to the appropriate length to achieve the appropraite boost we'll be OK.

IF not.. the only alternative is to add a manual boost controller. It'll act like a pressure diode. Blocking presssure to the actuator up until X psi. Once X psi is achieved BAM actuator moves and opens up the wastegate.

I also worked on my transmission a little bit more I had a going theory that the governor kicked out of its hole and was just moving (horizontally) freely. I figured that THAT would cause a whole host of issues involving governor pressure irregularities that might cause a second gear start.

So far I think that is the case. I opened the bore cover and turned the governor and it practically fell out of the bore. Snap ring came unseated OR was not fully seated to begin with. So I'll tackle that tomorrow and report back.

I also theorize that the second gear start would delay turbo spool enough that it would throw off the EDS's boost pressure sensor. EDS expects to see >500mBar (7 psi) at a certain time (I would imagine with respect to IP control rod travel)

That will remain to be seen after the transmission is all back together.

JamesDean · #6 09-30-2012, 12:02 PM

Update:

Transmission issues have been resolved. First gear is restored. The car pulls just as it did when I purchased it.

Now, according to my boost gauge (not sure how reliable it really is..) I am only getting a maximum of 5 psi of boost....

So... I'll have to check the gauge's plumbing and see again.

engatwork · #7 09-30-2012, 01:52 PM

Right now I'm just running full time vacuum to the existing wastegate actuator on the one I'm going to convert.

JamesDean · #8 09-30-2012, 04:57 PM

Jim,

What kind of boost numbers are you seeing at full time vacuum?

Eventually I will get to this modification as I think I've got some problem with one of the transducers. I'm only getting a small amount of boost as opposed to the 14 that I believe I should have..

I think the solution to this problem is best solved with the actuator that I picked up. (some cheap $40 unit that opened up at 7 psi, the ad said it was for a T25, T28..etc)

AND the installation of a wastegate controller. The one I linked to in a few post earlier was only $60 I think, so that will put the the replacement parts for the original mod's parts at the same price.. I think.

sixto · #9 09-30-2012, 05:20 PM

$60? Eps 8 $12 Boost Controller - YouTube

Sixto
87 300D

gsxr · #10 10-01-2012, 10:44 AM

Sounds normal to me. Boost is dependent on load. At a steady speed on a flat road, there may be zero boost. You're mostly concerned about seeing 12-14psi around 3000rpm at WOT and you've got that, so it should be fine.

JamesDean · #11 10-01-2012, 10:45 AM

Quote:

Originally Posted by gsxr

Sounds normal to me. Boost is dependent on load. At a steady speed on a flat road, there may be zero boost. You're mostly concerned about seeing 12-14psi around 3000rpp at WOT and you've got that, so it should be fine.

I will have to double check this 12-14 psi @ 3k/WOT. I dont believe I saw that on my 300D.

The car is not a dog really, it drives pretty well. The speedometer is pretty much useless under 40mph. It has a huge amount of bounce to it.

engatwork · #12 10-01-2012, 07:23 PM

I have not taken the time to run it with a boost gauge hooked up to it but will over the next few days. I just wanted to insure that the car will run like it is supposed to (performance wise) which it does

.

sixto · #13 10-01-2012, 07:41 PM

I find max boost an incomplete indicator. I spent time with an '87 300D that would run at 13-14 psi all day long but took all of the previous day to get there. As impractical as it is, 0-60 time tells a more complete story. 10 seconds is Dave/gsxr quick but you get your car from 20 seconds to 15 seconds and you feel ready to take on Garlits.

Sixto
87 300D

gsxr · #14 10-02-2012, 08:37 AM

Good point, Sixto. The 0-60 time is an excellent indicator. If a car is within a couple seconds of factory specs, AND max boost pressure is at spec, most likely it's running pretty well. Boost should build pretty quick, if you are cruising along and stand on the pedal, it should go to max boost within a few seconds. If not, the most likely reason is low fuel delivery (generally ALDA related).

engatwork · #15 10-11-2012, 08:40 PM

It will make 17 psi right now. The ALDA is still intact on the car. May try to tweek it when I come up with a way to control the boost pressure down a little.

I emailed them to see if the wastegate controllers are available yet.