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
  #136  
Old 10-31-2017, 09:40 AM
Father Of Giants's Avatar
Registered User
 
Join Date: Feb 2017
Location: Newport News, Virginia
Posts: 1,597
Quote:
Originally Posted by jake12tech View Post
The chain won't jump timing checking stretch ever unless there's something catastrophically wrong with the motor and rotating the crank won't do that.

Check stretch by lining the cam tower marks and getting the motor to TDC. If there isn't any stretch it will be at TDC. You will find stretch at your mileage, but are allowed 5 degrees. If you have that change the chain and pull the timing cover and do the rails too.
Thanks and a valve job requires head removal right?

__________________
1998 Ford Escort ZX2 5 speed - 279,000 miles My Daily

1992 Mercedes 300D 2.5 202,000 - Pure junk
2000 Mercedes E320 Black - 136,000 miles - Needs repair

Don't forget to grease the screw and threads on the spring compressor.
Reply With Quote
  #137  
Old 10-31-2017, 10:37 AM
Diseasel300's Avatar
Registered User
 
Join Date: May 2016
Posts: 6,025
Valve job requires head removal for certain. If your head is clean and warp-free like mine was (I got REALLY lucky), it is worth rebuilding. If it is warped, cracked, or looks like something dredged from Titanic, seek out a #17 or later head and have IT rebuilt for you. New guides, valves and seats ground, and a good solvent wash to clean the sludge out of the oil galleries. After that, treat it to new lifters and you'll have a top-end that's like new.

My engine had worn out valve guides. The originals were iron and do not have a long life expectancy. All 12 were worn to the point that the valves were "wiggly". The machinist I took my head to for rebuild was absolutely shocked that I was still getting 350+ PSI compression out of it like that. When I tried a leak-down test, #6 was leaking by the exhaust so badly that I couldn't even get pressure in the cylinder!
Reply With Quote
  #138  
Old 10-31-2017, 10:40 AM
Diseasel300's Avatar
Registered User
 
Join Date: May 2016
Posts: 6,025
Quote:
Originally Posted by Father Of Giants View Post
I always forget how to check stretch, also if the chain jumps it will give a false reading right?
If the chain jumps you'll be having more than just rough running issues. As said above, checking the chain "stretch" is easy. Spin the engine to TDC and set the crank pulley to exactly 0T. See if the mark on the camshaft is lined up with the mark on the cam tower. If it isn't, very slowly turn the crankshaft until it is, then read the timing mark on the crank pulley. That is your "stretch" in degrees.

It's possible that someone could have replaced the chain before. I suspect that has happened in my car. I have right at 1˚ of timing chain stretch which seems implausibly low at my mileage (the odo says 179K, the body and drivetrain say that ODO didn't work for a LONG time...).
Reply With Quote
  #139  
Old 10-31-2017, 10:51 AM
Father Of Giants's Avatar
Registered User
 
Join Date: Feb 2017
Location: Newport News, Virginia
Posts: 1,597
Quote:
Originally Posted by Diseasel300 View Post
Valve job requires head removal for certain. If your head is clean and warp-free like mine was (I got REALLY lucky), it is worth rebuilding. If it is warped, cracked, or looks like something dredged from Titanic, seek out a #17 or later head and have IT rebuilt for you. New guides, valves and seats ground, and a good solvent wash to clean the sludge out of the oil galleries. After that, treat it to new lifters and you'll have a top-end that's like new.

My engine had worn out valve guides. The originals were iron and do not have a long life expectancy. All 12 were worn to the point that the valves were "wiggly". The machinist I took my head to for rebuild was absolutely shocked that I was still getting 350+ PSI compression out of it like that. When I tried a leak-down test, #6 was leaking by the exhaust so badly that I couldn't even get pressure in the cylinder!
I don't have a garage. How can i protect the engine with the head off?
__________________
1998 Ford Escort ZX2 5 speed - 279,000 miles My Daily

1992 Mercedes 300D 2.5 202,000 - Pure junk
2000 Mercedes E320 Black - 136,000 miles - Needs repair

Don't forget to grease the screw and threads on the spring compressor.
Reply With Quote
  #140  
Old 10-31-2017, 10:57 AM
funola's Avatar
Registered User
 
Join Date: May 2005
Location: NYC
Posts: 8,245
Diseasel300, surprised with the iron valve guides, did Mercedes use that in the 617 engines also?

Father Of Giants, you've done a lot and learned a lot with this car. Great job! You've had great help!
__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked
Reply With Quote
  #141  
Old 10-31-2017, 11:03 AM
Diseasel300's Avatar
Registered User
 
Join Date: May 2016
Posts: 6,025
Quote:
Originally Posted by Father Of Giants View Post
I don't have a garage. How can i protect the engine with the head off?
Spray the exposed surfaces with WD-40 or rub with engine oil, then wrap with plastic and a bungee cord or duck tape. You want to keep the weather/moisture out. The head will likely be in the shop for a week or two depending on how busy they are and whether or not they have to order parts. The oil on the exposed surfaces will help prevent any rusting if any moisture does make it past the plastic.

If you pull the head to have it rebuilt, order a head gasket kit and new head bolts while you have it in the shop. You will need a copy of the FSM for removal and installation of the head, there's a specific order to go in to prevent warpage and a specific tightening sequence that requires some herculean strength and a cheater bar.

Before taking the head off, make sure your leakage/problems are coming from the head/top-end. A leak-down test (even if not perfectly performed) will tell you where the air is escaping. If it's coming out the crankcase, it isn't worth doing the top end. If you hear the air coming out of either manifold or through the coolant overflow bottle, get after it.

When I originally got my car, I had ~320 PSI compression on #4 and #6. Post rebuild, I'm >390 on both. My last compression test was this past winter not long after the car went back on the road, and the car runs better now than it did then, so I'd estimate the compression is probably >400PSI now on all cylinders since it's had time to break itself in now.
Reply With Quote
  #142  
Old 10-31-2017, 11:54 AM
Diseasel300's Avatar
Registered User
 
Join Date: May 2016
Posts: 6,025
Quote:
Originally Posted by funola View Post
Diseasel300, surprised with the iron valve guides, did Mercedes use that in the 617 engines also?
Having never owned a 617, I have no idea. The ones in the SDL were definitely iron, I got them back from the machinist and have since chunked them. They were definitely ferrous (magnetic) and visibly worn. The replacement guides are phosphor-bronze. I don't know if this was something they did only in the early engines or if it was common for all the OM603's. Prior to my teardown, I don't think the engine had ever been apart before, so I can only assume that was factory equipment. Everything else still had factory logos on it.

If the 617's do have iron valve guides, I'd expect them to be better suited to the task since the 617 uses rocker arms to actuate the valves instead of a hydraulic bucket tappet directly acting on the valve stem.
Reply With Quote
  #143  
Old 10-31-2017, 12:07 PM
jake12tech's Avatar
Registered User
 
Join Date: Nov 2011
Location: Philadelphia, PA
Posts: 2,878
Quote:
Originally Posted by Diseasel300 View Post
If the chain jumps you'll be having more than just rough running issues. As said above, checking the chain "stretch" is easy. Spin the engine to TDC and set the crank pulley to exactly 0T. See if the mark on the camshaft is lined up with the mark on the cam tower. If it isn't, very slowly turn the crankshaft until it is, then read the timing mark on the crank pulley. That is your "stretch" in degrees.

It's possible that someone could have replaced the chain before. I suspect that has happened in my car. I have right at 1˚ of timing chain stretch which seems implausibly low at my mileage (the odo says 179K, the body and drivetrain say that ODO didn't work for a LONG time...).
Not unlikely that your chain has not been replaced. These double row chains last easily 300k or more if properly maintained with correct oil and intervals on time. Mine was not replaced till 330k on my om606 engine. My om602s all had originals at 300k or more and were still in tolerance.
__________________
Only diesels in this driveway.
2005 E320 CDI 243k Black/Black
2008 Chevy 3500HD Duramax 340k
2004 Chevy 2500HD Duramax 220k
Reply With Quote
  #144  
Old 10-31-2017, 01:11 PM
Diseasel300's Avatar
Registered User
 
Join Date: May 2016
Posts: 6,025
Quote:
Originally Posted by jake12tech View Post
Not unlikely that your chain has not been replaced. These double row chains last easily 300k or more if properly maintained with correct oil and intervals on time. Mine was not replaced till 330k on my om606 engine. My om602s all had originals at 300k or more and were still in tolerance.
Whatever the situation is, I'm not concerned about it. The sprockets still have square teeth, the chain isn't sloppy, and the stretch is within allowable limits. It'll stay put for quite a while longer.
Reply With Quote
  #145  
Old 11-01-2017, 10:20 AM
#TRUMP2020
 
Join Date: Jun 2012
Location: Virginia
Posts: 789
Quote:
Originally Posted by Father Of Giants View Post
I don't have a garage. How can i protect the engine with the head off?
Don't rebuild your cylinder head. Buy a used cylinder head, have that one rebuilt, and then you can swap yours out inside of a day, without waiting on the machine shop.
__________________
1998 E300 turbodiesel

America's Rights and Freedoms Are Not The Enemy!
Reply With Quote
  #146  
Old 11-01-2017, 10:24 AM
#TRUMP2020
 
Join Date: Jun 2012
Location: Virginia
Posts: 789
Quote:
Originally Posted by jake12tech View Post
Not unlikely that your chain has not been replaced. These double row chains last easily 300k or more if properly maintained with correct oil and intervals on time.
So many people have trouble with the bold part though. The thought of how can I do this *properly* never crosses their mind. Priority 1 is how can I do this the *absolute cheapest* way possible.
__________________
1998 E300 turbodiesel

America's Rights and Freedoms Are Not The Enemy!
Reply With Quote
  #147  
Old 11-01-2017, 11:50 AM
Diesel Preferred
 
Join Date: Oct 2007
Location: Charleston SC
Posts: 2,788
Quote:
Originally Posted by Father Of Giants View Post
Did a compression test.

#1 405
#2 [suspect cylinder] 300 , 320
#3 360
#4 435
#5 400
#6 [suspect cylinder] 370, 385


#2 is very low, however #6 is acceptable but still doesn't combust completely.
Completely agree that #2 is an issue. Note that #6 is higher than #3, but you haven't found an issue with #3? Could this mean that #6 has a fuel issue (injector or delivery valve) in addition to the compression issue?

I've got a decent used head that I pulled off a 3.5 liter motor (unknown mileage), it's a #20 casting. One issue you'd have is that this head has oblique injection, so different injectors than what your car has if your head is original, and I don't have a spare set of injectors for it. Contact me off list if you are interested. I really need to get it tested for cracks, probably time to do that.

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC
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 12:48 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, 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