Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help




Go Back   PeachParts Mercedes ShopForum > Technical Information and Support > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 03-01-2005, 09:04 PM
Registered User
 
Join Date: Feb 2005
Location: Denison, Texas
Posts: 290
Turbo

I finally had success with my turbo boost problem. I adjusted wastegate in 4turns I guess my spring in the wastegate was very weak the boost pressure is now 13psi at ALDA at 3600rpm. The car still does not seem like it was when
I first bought it at 65000 mi. I remember the car would pin your head against the head rest at about 1200 rpm if you really pushed the pedal down, it does not feel like it has the low end boost anymore. Is there any way you can tell if the ALDA is providing the factory enrichment that it had when it came from the factory. Thanks Brian and everbody that helped me get this far.
Reply With Quote
  #2  
Old 03-01-2005, 09:27 PM
R Leo's Avatar
Stella!
 
Join Date: Mar 2003
Location: En te l'eau Rant
Posts: 5,367
What kind of engine? 617, 603 etc???

Regardless, whatever engine you are running, with any kind of a load you should have full boost by 2100 to 2300-something rpm. Try hard acceleration on a long grade and see what kind boost you are making at WOT at various rpms.

Quote:
Is there any way you can tell if the ALDA is providing the factory enrichment that it had when it came from the factory.
Not exactly. However, you can diddle the ALDA and you'll probably see some bottom end improvement. Search the forum for ALDA how-tos.

Report back with your results.
__________________
Never a dull moment at Berry Hill Farm.
Reply With Quote
  #3  
Old 03-01-2005, 10:01 PM
Old Geek's Avatar
Registered User
 
Join Date: Mar 2005
Location: Houston
Posts: 31
Smile

Quote:
Originally Posted by lakerat
. Is there any way you can tell if the ALDA is providing the factory enrichment that it had when it came from the factory. Thanks Brian and everbody that helped me get this far.
----
There is a way -> Brief method -Turn the ALDA adjustment screw 1 turn CCW. Then test drive. If there is no smoke, go add another 1/4 turn CCW; repeat the 1/4 turns CCW until you see smoke during accel. Once you see smoke, then go 1/4 turn CW. That should make 'off the line' accel better...
Reply With Quote
  #4  
Old 03-01-2005, 10:26 PM
Registered User
 
Join Date: Feb 2005
Location: Denison, Texas
Posts: 290
I have adjusted it all the way CCW and never saw an increase in smoke but did see a little more pep at low rpm, I have leak tested the ALDA also and it hods pressure for a long time. Would a new ALDA bring the enrichment back to factory specs. It also made the tran. shift a little less crisp.
Reply With Quote
  #5  
Old 03-01-2005, 11:25 PM
R Leo's Avatar
Stella!
 
Join Date: Mar 2003
Location: En te l'eau Rant
Posts: 5,367
Quote:
Originally Posted by lakerat
Would a new ALDA bring the enrichment back to factory specs?
Not if it is holding pressure OK now. If the adjustment is fully CCW, your ALDA probably needs some shims underneath it to compensate for wear in the IP. The softened shifting phenomenon is due to a change in power output because of the ALDA adjustment...less throttle is now needed to accomplish the same acceleration so now there's more vacuum at the transmission modulator which will in turn produce softer shifts.
__________________
Never a dull moment at Berry Hill Farm.

Last edited by R Leo; 03-01-2005 at 11:30 PM.
Reply With Quote
  #6  
Old 03-01-2005, 11:46 PM
Banned
 
Join Date: May 2002
Location: Blue Point, NY
Posts: 25,396
Quote:
Originally Posted by lakerat
I finally had success with my turbo boost problem. I adjusted wastegate in 4turns I guess my spring in the wastegate was very weak the boost pressure is now 13psi at ALDA at 3600rpm. The car still does not seem like it was when
I first bought it at 65000 mi. I remember the car would pin your head against the head rest at about 1200 rpm if you really pushed the pedal down, it does not feel like it has the low end boost anymore. Is there any way you can tell if the ALDA is providing the factory enrichment that it had when it came from the factory. Thanks Brian and everbody that helped me get this far.
That is good news. I agree with eveyone else who posted on this thread.

Just for future reference. Your experiences with this vehicle would be quite valuable for someone in the future. Unfortunately, you have split it up into three separate threads. There is no way to ever get continuity with what you have done.

In the future, please continue with the very first thread, no matter how old it was. It will be an excellent reference.
Reply With Quote
  #7  
Old 03-02-2005, 08:40 AM
dannym's Avatar
I'm not here
 
Join Date: Oct 2004
Location: Deltona, Florida
Posts: 2,360
Quote:
Just for future reference. Your experiences with this vehicle would be quite valuable for someone in the future. Unfortunately.
Yeah, me! This is very interesting to me because I have the same situation. My ALDA is dialed all the way ccw and it doesn't seem to have the acceleration that it should. I am going to check the timing chain and IP timing but in the meantime I would like to know how things turn out.

Lakerat, if you come across any interesting forums please post a link to them here.

Danny
__________________
1984 300SD Turbo Diesel 150,000 miles

OBK member #23

(\__/)
(='.'=) This is Bunny. Copy and paste bunny into your
(")_(") signature to help him gain world domination
Reply With Quote
  #8  
Old 03-02-2005, 09:18 AM
R Leo's Avatar
Stella!
 
Join Date: Mar 2003
Location: En te l'eau Rant
Posts: 5,367
Boost Stats — Your Results May Vary

Here's what lovely and charming Marlene (OM617.952) does for boost.

Slight grade in third gear (remember, she's a manual), 650ft MSL, 48F

1500 RPM, approximately 1/3 throttle, holding speed on grade: 5-6 psi
1800 RPM, approximately 1/3 throttle, accelerating on grade: 6-7 psi
2000 RPM, approximately 1/3 to 1/2 throttle, accelerating: 8-8.5 psi
2200 RPM, approximately 1/2 throttle, accelerating: 8.5-9 psi
2500 RPM, approximately 3/4 throttle, accelerating: 9-10 psi

Level ground, drifting (1/8 throttle) at 1800 rpms generates about 3-5 psi.

FWIW, my wastegate opens fully at approximately 10 psi; I may change it to spec someday.
__________________
Never a dull moment at Berry Hill Farm.
Reply With Quote
  #9  
Old 03-02-2005, 09:52 AM
Registered User
 
Join Date: Feb 2005
Location: Denison, Texas
Posts: 290
I remember when I first bought my car I sped my rpm up to about 1200 and put a pair of vicegrips to lock it at that rpm to check something and within about a minute the engine started running away I guess after the turbo started building boost, now I have no boost untill about 2000 rpm is this do to the ALDA or do I need to dial the wastegate in a little more.
Reply With Quote
  #10  
Old 03-02-2005, 10:11 AM
Banned
 
Join Date: May 2002
Location: Blue Point, NY
Posts: 25,396
Quote:
Originally Posted by lakerat
I remember when I first bought my car I sped my rpm up to about 1200 and put a pair of vicegrips to lock it at that rpm to check something and within about a minute the engine started running away I guess after the turbo started building boost, now I have no boost untill about 2000 rpm is this do to the ALDA or do I need to dial the wastegate in a little more.
You had indicated, previously, that the ALDA is holding pressure. That's the first indication that it is working properly, so, I would leave it alone for now.

You typically won't get any boost until 2000 rpm because the exhaust volume isn't very high, especially on level ground.

Check for boost at 3000 rpm with full pedal. You can adjust the wastegate until you get 11-12 psi. Don't dial the wastegate more than this.
Reply With Quote
  #11  
Old 03-02-2005, 11:47 AM
R Leo's Avatar
Stella!
 
Join Date: Mar 2003
Location: En te l'eau Rant
Posts: 5,367
Quote:
Originally Posted by lakerat
I remember when I first bought my car I sped my rpm up to about 1200 and put a pair of vicegrips to lock it at that rpm to check something and within about a minute the engine started running away I guess after the turbo started building boost, now I have no boost untill about 2000 rpm is this do to the ALDA or do I need to dial the wastegate in a little more.

The Bosch injection pump used in the OM617.952 is ungoverned above 1000 rpm; that's why your engine 'ran away'. Theoretically, the engine would continue to increase in rpm until it reached the max rpm limit set in the IP.

However, if it truly did take a full minute for the turbo to spool and the engine to begin to rev as you've indicated, then you may well have problems with the turbo itsself. On both of my turbo 617s, if you advance the throttle to rev the engine slightly above 1000 rpm, the engine will immediately begin to rev up like it is out of control. Slow build of boost sounds like a draggy turbo.

With the engine shut down, you should pull the 'u' pipe off of the turbo intake and spin the compressor side of the turbo with your fingers. The compressor should spin realtively freely and continue to turn for a couple of revolutions. There should be ZERO radial play in the compressor and little to no axial play either. If the compressor shows excessive play or will not spin relatively freely you have turbo issues.
__________________
Never a dull moment at Berry Hill Farm.
Reply With Quote
  #12  
Old 03-02-2005, 07:15 PM
Registered User
 
Join Date: May 2002
Location: Central Oregon
Posts: 1,004
Can anyone confirm...

I was informed by a turbo shop (not local) that the turbo bearings are free floating meaning that lateral movement of the shaft when stationary would be acceptable.
__________________
'99 S420 - Mommies
'72 280SE 4.5 - looking to breathe life into it
'84 300SD Grey - Sold
'85 300SD Silver - Sold
'78 Ski Nautique
Reply With Quote
  #13  
Old 03-02-2005, 08:13 PM
Johnhef's Avatar
Senior Member
 
Join Date: Feb 2005
Location: Frederick, Md
Posts: 4,540
I've always heard (and believed) the same thing. a little play should be acceptable.
__________________


1980 500SE/AMG Euro
1981 500SEL Euro
1982 380SEL
1983 300TD
1983 500SEC/AMG Euro
1984 500SEC
1984 300TD Euro
1986 190E 2.3-16
1986 190E 2.3
1987 300D
1997 C36 AMG
2003 C320T 4matic

past: 1969 280SE 4.5 | 1978 240D | 1978 300D | 1981 300SD | 1981 300SD | 1982 300CD | 1983 300CD | 1983 300SD | 1983 380SEC | 1984 300D | 1984 300D | 1984 300TD | 1984 500SEL | 1984 300SD | 1985 300D | 1986 300E | 1986 560SEL | 1986 560SEL/Carat | 1987 560SEC | 1991 300D 2.5 | 2006 R350
Reply With Quote
  #14  
Old 03-15-2005, 10:36 AM
Registered User
 
Join Date: May 2002
Location: Central Oregon
Posts: 1,004
Question on max boost

According to the manual when testing a turbo for boost it indicates that you are looking for .7 to .8 bar or 10.15 to 11.6 psi respectively.

I am assuming that on an older engine you would not want to up your boost too much as you wil start cooking the engine.
How high is safe? On my recent foray into California I was making only 9.2 psi at max throttle while climbing the grades in No. Cal.
I did manage to make it jump to 10.2 once while downshifting but I assume this is normal and a short (I mean a few seconds at most) spike like this willnot adversely affect the engine.

Do you think I can dial it up to say 11.0 safely. This is on the 81 SD with only 169,000 on the clock.
__________________
'99 S420 - Mommies
'72 280SE 4.5 - looking to breathe life into it
'84 300SD Grey - Sold
'85 300SD Silver - Sold
'78 Ski Nautique
Reply With Quote
  #15  
Old 03-15-2005, 10:46 AM
Banned
 
Join Date: May 2002
Location: Blue Point, NY
Posts: 25,396
You could dial it up to 15 if you wanted to, but, you would need to monitor the EGT.

It's not the level of boost that is the significant parameter for determining engine damage. It's the exhaust gas temperature.

If you ran 15 psi for 30 seconds, the EGT wouldn't climb enough to do any piston damage. But, if you ran it for ten minutes, you might be in for some unwelcome surprises.

Since the spec allows up to 12 psi, I'm fairly sure you wouldn't have any problems at 11 psi.

Also, note that these are sea level specs. You could run additional boost (at the same exhaust temperatures) as you increase altitude. But, then, sea level becomes a problem without a proper EGT guage.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Broken Turbo msyoder Diesel Discussion 33 07-05-2005 04:12 PM
5cy Turbo D, Too much Turbo Whistle? coachgeo Tech Help 4 03-02-2005 02:35 AM
Turbo Trouble patterson Diesel Discussion 20 10-02-2002 12:05 PM
turbo 16v jasondew Performance Paddock 4 03-27-2002 08:16 AM
Turbo Failure after 200 miles 300sdlguy Tech Help 6 05-29-1999 08:40 PM



All times are GMT -4. The time now is 12:18 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page