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-Benz Forum > Mercedes-Benz Tech Information and Support > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 08-09-2007, 12:19 PM
Registered User
 
Join Date: Oct 2001
Location: around Charlotte NC
Posts: 586
3.5L OM 603 - Injector torque and heat shield

Folks,

We're doing a compression check on my 93 300SD. The good news is all cylinders came out pretty good, in the 420-450psi range. When we pulled the injectors out there were no "loose" heat shields underneath the injectors. Do the 3.5L engines use them like the 3.0 engines? Some of the history on this car is unknown so someone could have removed and reassembled the injectors in the past and left them out. I have an 86-87 OM603 manual and it says to use them.

Also, is the torque on the injectors the same for the 3.5L? The manual says about 75 nm... which I'm guessing is around 55 lb-lbs?

Thanks

Reply With Quote
  #2  
Old 08-10-2007, 08:43 AM
Registered User
 
Join Date: Oct 2001
Location: around Charlotte NC
Posts: 586
Found the answers, history and on to the next test - turbo.

Folks,

Thanks to Mercedesshop for looking things up for me and confirming on the heat shields. All went back together fine and it fired right up.

I'm searching for the cause of some very heavy oil consumption on this 3.5L OM603. All guesses would point to the rodbending scenario, but 2 very respected mechanics are telling me it just runs too good.... so we're taking the diagnosis step by step.

The engine runs great, doesn't overheat, no knocking at now just under 160K miles. I'm burning a quart of oil in what I thought was 300 miles, but this last trip back and forth to Raleigh says it may be a quart per 500 miles. A lot anyway. Let the car idle and there is some visible smoke. After idling for 60 seconds, goose it and a big plume of blue oil smoke comes out of the tailpipe.

The compression check had good results. All cylinders were in the 420-450 psi range if I remember correctly from yesterday. We did see some goo in the intake crossover. I had someone else look at it a year ago and they may have cleaned the intake, because there was not a huge accumulation, but the coating was damp not dry. So at the suggestion of Mercedesshop and my buddy I'm working with in Raleigh we decided to test the turbo - intake side at least.

We cleaned the output path of the turbo that attaches to the intake real well, then ran it an spun the engine up to around 3000 rpm for 30 seconds. We saw "tracks" of new oil on the output side of the turbo. So we wiped it down and repeated, and same results - more tracks. Holding a piece of cardboard over the output got a few minor specs of wet oil in the 30 seconds of testing. I guess this would add up over time.

Blue smoke was still coming out of the tailpipe even with the turbo input not engaged, but there may be residual oil in there or leakage on the exhaust side as well. We haven't seen the exhaust side yet, but plan on pulling the entire turbo out today.

On futher inspection of the turbo housing, it appears it may have been rebuilt in the past. There are some markings with numbers stamped into the unit. Our collective opinion here is the turbo is suspect enough to pull and determine if a rebuild is needed. Turbocity in California says about $300 to rebuld....

As always, I'd love to hear your opinions and suggestions.
Reply With Quote
  #3  
Old 09-18-2007, 01:30 PM
Registered User
 
Join Date: Jul 2005
Posts: 81
I drive a 1991 350 SD with 190,000 miles. Oil consumption is now about one quart per 500 miles. Coincidently, I'm taking a diesel technology evening course at the local community college. I can pull the engine and perform the rebuild at school, assuming the engine is kaput after some careful diagnosis. Is there a post with procedures, part numbers, specs, etc. for the rebuild? I'm having difficulty purchasing the factory repair manual. Any suggestions for upgraded rods, and documentation?

Thanks in advance.

Greg
Reply With Quote
  #4  
Old 09-18-2007, 01:54 PM
vstech's Avatar
DD MOD, HVAC,MCP,Mac,GMAC
 
Join Date: Mar 2006
Location: Mount Holly, NC
Posts: 26,835
I do not believe the 3.5L block is rebuildable... the bent rod warps the cylinders. good luck! take pictures if you can, we love seeing the inside of these modern marvels!
__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!
Reply With Quote
  #5  
Old 09-19-2007, 12:11 AM
Registered User
 
Join Date: Oct 2001
Location: around Charlotte NC
Posts: 586
can rebuild with some effort and cost.

There are sleeves for the 3.5L... see this note from Germanstar ....

"Yes, we carry the sleeves for $39 each.

Ron Parker
German Star Mercedes Parts
http://www.germanstar.net
(800) 377-6598"

Of course it would take significant machine work. From what I have been able to get from folks that have been through this is they end up spending $3-4000 in parts and machinist labor to get the rebuild done. I think Noels ( Florida) has gone up, but will have a complete long block rebuilt for $7500, they are experts that do many per month, and you get a warranty. The other option is find a good 3.0L short or long block and swap it in.

Last year I was burning a quart of oil in around 300 miles. It runs great, good mileage, and is quiet. Then I had ignition switch issues last year and parked it. My car is now a hobby and not a daily driver so I have some schedule flexibility.

My current state is I started an exploration to solve this with a friend. Neither of us is a MB diesel expert, he is a pretty astute auto wrencher. So I get some time now and we did a compression test and all cylinders came out in the 420-450 psi range. We pulled the crossover pipe off the intake and see oil. Then we cleaned the turbo output that would go to the intake and started and ran the car for 30-60 seconds. We saw oil tracks coming from the turbo, not good. I'll try to post pictures ( should be attached, one after running 60 seconds then other cleaned - they are in reverse order).

I sent it off to a rebuild at turbocity. It is back on and running. I had a couple weeks of ignition issues again with the hot weather, but it has now cooled and the ignition is working again. I am 200 miles into a new oil change and it appears the consumption is less, but still significant. If I sit a light for 60 seconds, when I pull away there is a blue cloud. I'll run it a bit more and report back. I expect I am at the 5-600 miles per quart rate now.

So the question to this group of experts is .... any other possible issue such as valve guides or seals at 158K miles? Is there a test for valve seals? Maybe some kind of EGR failure? I have a head gasket kit. If I pull the head do I need new head bolts? I saw a mention on measuring them - so they appear to be the streching type.

Otherwise probably time to fix/replace the bottom end.

Chuck
Attached Thumbnails
3.5L OM 603 - Injector torque and heat shield-img_2482.jpg   3.5L OM 603 - Injector torque and heat shield-img_2483.jpg  


Last edited by CSchmidt; 09-19-2007 at 12:18 AM.
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




All times are GMT -4. The time now is 12:17 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page