How do you know if your turbo is working properly? - PeachParts Mercedes-Benz Forum

Actvs Dei · #1 12-24-2005, 12:04 AM

I have a 1982 300D. Runs great. But im not sure if the turbo is working properly. When I accelerate it seems sluggish. Should there be a noticable boost? And if so when should that boost occur? I dont have anything to compare it with so Im not sure. When it comes to the turbo is it a all or nothing kind of thing? either its working or its not? Another question.. can the car function as a regular diesel if the turbo is completely non functioning?

TheDon · #2 12-24-2005, 12:29 AM

sounds like the problems i had when i got my 300D.. tune your ALDA i did that and i felt a noticable difference.. and clean the banjo bolts.. if you suspect your turbo is broken do this simple test which board members here told me to try

remove the air cleaner and u-tube that goes to the intake of the turbo.. with the engine off and cold see if you can freely spin the turbo .. if you can your turbo is in good shape.. and check for shaft play by trying to move it back and forth .. just be gentle

of course it can function as a regular diesel.. it will just be slower than the turbo models.. not like they are rockets but it is noticable

sailor15015 · #3 12-24-2005, 12:48 AM

If you haven't messed with the ALDA then the turbo will probably feel like it kicks in around 2500-3000. The ALDA is the square thing on the back of the injection pump. There's a "tamper proof" seal on it and under that is a lock nut and adjusting screw. Losen the nut and turn the adjusting scew counter-clockwise a half turn or so. Keep doing this until you feel the same amount of power from a dead stop, i.e. it feels like there's always boost. Also yes do check that the small hose from the back of the intake manifold is clear and hooked up. Another thing that can happen is that the mess of throttle linkage tends to wear out after a while. On the bottom of the stop lever is a rod that disapears down beside the injector pump. Look down there and have an assistant press the pedal all the way down. Verify that the little swinging arm comes all the way to rest against the stop in the full-throttle position. If it doesn't then adjust the linkage as necessary to correct this. Just watch it move a few times, think really hard, and you'll understand what to adjust. That's what I had to do to figure it out. I adjusted the ALDA and the linkage on the '84 when it still belonged to my brother and it gave him second thoughts about selling it to me! It was like a completely different car.

TheDon · #4 12-24-2005, 12:56 AM

Quote:

Originally Posted by sailor15015

If you haven't messed with the ALDA then the turbo will probably feel like it kicks in around 2500-3000. The ALDA is the square thing on the back of the injection pump. There's a "tamper proof" seal on it and under that is a lock nut and adjusting screw. Losen the nut and turn the adjusting scew counter-clockwise a half turn or so. Keep doing this until you feel the same amount of power from a dead stop, i.e. it feels like there's always boost. Also yes do check that the small hose from the back of the intake manifold is clear and hooked up. Another thing that can happen is that the mess of throttle linkage tends to wear out after a while. On the bottom of the stop lever is a rod that disapears down beside the injector pump. Look down there and have an assistant press the pedal all the way down. Verify that the little swinging arm comes all the way to rest against the stop in the full-throttle position. If it doesn't then adjust the linkage as necessary to correct this. Just watch it move a few times, think really hard, and you'll understand what to adjust. That's what I had to do to figure it out. I adjusted the ALDA and the linkage on the '84 when it still belonged to my brother and it gave him second thoughts about selling it to me! It was like a completely different car.

to get into that tamper proof seel get some needle nose pliers and pry the metal away.. and tear the plastic cap off..

sailor15015 · #5 12-24-2005, 12:58 AM

That plastic cap was easy but the metal part was a royal PITA. It was cold and I was in a hurry so its still mostly on there. As soon as I can get it rolling again then I'll fix it.

whunter · #6 12-24-2005, 01:11 AM

Start the diagnosis slow and simple.

If the ALDA is not getting air PRESSURE (not vacuum) from the intake = no boost.

Banjo Bolt
http://www.peachparts.com/shopforum/showthread.php?p=733935&posted=1#post733935

Note:
After you get the ALDA/turbo function corrected, the engine will need an "Italian Tune up".
Italian Tune up
Italian Tune up

#7 12-24-2005, 05:03 AM

Yes check all lines feeding the ALDA and also check out the switchover valve.

Whunter gave you some good links there

Actvs Dei · #8 12-24-2005, 02:44 PM

I cleaned some gunk out of the lines and its working much better now

I would like to replace some of those hard clear lines but all I find on fastlane are the black vacuum hoses. what are those hard clear vacumm lines called?

Brian Carlton · #9 12-24-2005, 02:59 PM

Quote:

Originally Posted by Actvs Dei

I cleaned some gunk out of the lines and its working much better now

I would like to replace some of those hard clear lines but all I find on fastlane are the black vacuum hoses. what are those hard clear vacumm lines called?

Those lines are 4 mm "Tecalan" lines. You can get them by the meter at the local stealer. Not too much $$$.