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 11-18-2013, 10:10 PM
Registered User
 
Join Date: Aug 2000
Location: Houston, Texas
Posts: 325
Low compression in cylinder 1 on 240D

Hello to the group. I've been having a rough idle problem/starting problem on my 240D that started in June. Starting was getting more and more difficult but ran fine after start. The car does use oil which is about a quart every 600 miles.

Then one day all of a sudden the engine started running as though on only 3 cylinders and had a very rough idle. I did a compression test and all cylinders were around 300-340 except cylinder number 1 which was 100 which explained why it ran so rough. So I did the simple test to see if it was either the valves or the rings so I poured about 1 tablespoon of oil into the glow plug hole and did a retest of the compression.....similar result....about 110. I decided it was the valves because the compression never came up appreciably.

Last month I pulled the head off and sent it off to the machine shop that specialises in head rebuilding. The head came back professionally rebuilt with brand new exhaust valves and a brand new gasket kit with new head gasket. Installed the head and attempted a start. I got the same result. It was very hard to start but eventually got it stated and ran rough at idle just like before but seemed to run a little better. I did another compression test and the results came out the same with number 1 cylinder at 100. I poured some oil into number 1 cylinder and retested the compression I still have the same low compression. I always though that if it was the rings, the compression would shoot way up with the oil poured into the cylinder......this never happened during the compression test. What am I doing wrong? I am so discouraged by this after spending all the time and money taking the head off and getting it rebuilt just to have the same results. I know it isn't the head so it's got to be the rings but can the rings be so bad that the oil can't make a temporary seal for the test? I've read Marvel Mystery Oil but does that really help? What do you guys think?

Thanks

Herb

Reply With Quote
  #2  
Old 11-18-2013, 10:23 PM
Registered User
 
Join Date: Aug 2012
Location: Central Ohio
Posts: 105
100 is awfully low, maybe a ring actually broke or stuck and it's just too much of a space for some oil to compensate for it..... I'd say you're past the point of Marvel Mystery Oil being helpful.

I'm sure it's really discouraging to have done all of that head work only for the bottom end to be the issue, but just think of how awesome your car will be once you either redo or replace the bottom end!
Reply With Quote
  #3  
Old 11-18-2013, 10:34 PM
Registered User
 
Join Date: Mar 2009
Location: San Diego
Posts: 3,099
I resurrected a 190D OM601 engine with low compression in cyl 1, also < 100psi, by doing the following.

1) removed head.
2) removed oil pan and pushed all pistons out from below.
3) honed cylinder 1, cleaned ring grooves, load of carbon, replaced rings.
4) It bought the compression back to > 300psi ( cold ).
5) The compression on the other 3 cyl are OK but I cleaned the ring grooves anyway.
6) Now the engine runs like a champ.

I am not sure how easy to do it with a OM616 but you may be in luck as it is cyl 1. It may be possible to push the cyl 1 piston out by removing the lower oil pan only.

Good luck.
__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.
Reply With Quote
  #4  
Old 11-18-2013, 10:35 PM
Diesel911's Avatar
Registered User
 
Join Date: Sep 2007
Location: Long Beach,CA
Posts: 35,965
What did the Cylinder look like when you had the Head off. Broken Piston Rings will sometime score the Cylinder.

Despite the comment on the Marvel Mystery Oil I think it is worth a try.

Remove a Glow Plug and dump about 1/4 cup into the GP hole and let it sit for 1 weak. Rotate the Engine and repeat the does for another Week.
In fact if you have the time repeat the one week treatment as many times as you like till the Bottle is empty.

You will need to change the Oil before you drive it due to the Marvel Mystery Oil in it.
Or I suppose you could drain out the Oil before you start the Marvel Mystery Oil treatment and reinstall the same Oil before you run the Engine. If I did this I would have to put a Note on the Steering Wheel not to start the Car and not remove the note until the Oil back in the Crankcase.

There is other chemicals People have dumped into the cylinder that are stronger then the MM Oil and they are in some of the sticking ring threads.

I am curious why you did not measure the Cylinder Bores while the Head was off to get some idea what was going on?
__________________
84 300D, 82 Volvo 244Gl Diesel
Reply With Quote
  #5  
Old 11-18-2013, 10:53 PM
dkveuro's Avatar
Sword of Damocles
 
Join Date: Jun 2003
Location: Here an' there.
Posts: 2,548
This is the very reason I use a cylinder pressure tester. I bought it from Assenmacher(?) some time ago. I tried to buy a larger one ( 4 inch bores.. up to 6 inch.) last year but they told me they stopped making them.

It uses bolts through two swing arms to hold down a rubber sealed plate to the top of the cylinder bore gasket deck. It has a shop air line attachment so you can use your 'leak down' tool to see if each cylinder is good, or needing attention before you fit the cylinder head.

Saved me many a time and do this to new motors I build too.


.
__________________
[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ]

"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."
Reply With Quote
  #6  
Old 11-18-2013, 10:53 PM
Registered User
 
Join Date: Jul 2008
Posts: 3,740
Was any alternative fuels ever used with the engine? Did you do a valve adjustment after the head was back to insure the gaps were correct?
__________________
Reply With Quote
  #7  
Old 11-18-2013, 10:55 PM
Registered User
 
Join Date: Aug 2000
Location: Houston, Texas
Posts: 325
Quote:
Originally Posted by Diesel911 View Post
What did the Cylinder look like when you had the Head off. Broken Piston Rings will sometime score the Cylinder.

Despite the comment on the Marvel Mystery Oil I think it is worth a try.

Remove a Glow Plug and dump about 1/4 cup into the GP hole and let it sit for 1 weak. Rotate the Engine and repeat the does for another Week.
In fact if you have the time repeat the one week treatment as many times as you like till the Bottle is empty.

You will need to change the Oil before you drive it due to the Marvel Mystery Oil in it.
Or I suppose you could drain out the Oil before you start the Marvel Mystery Oil treatment and reinstall the same Oil before you run the Engine. If I did this I would have to put a Note on the Steering Wheel not to start the Car and not remove the note until the Oil back in the Crankcase.

There is other chemicals People have dumped into the cylinder that are stronger then the MM Oil and they are in some of the sticking ring threads.

I am curious why you did not measure the Cylinder Bores while the Head was off to get some idea what was going on?
Diesel911,
I didn't get a chance to see the cylinder itself when I had the head off fearing that turning the crank would mess up the timing of injection pump during the time I had tension of the chain; it would be my luck that as I turned the crank, the chain would somehow get loose and mess up timing at the injection pump.

At the time the piston was at TDC for cylinder 1 so there wasn't any way for me to look for scoring. I didn't measure the cylinder bores unfortunately but I was able to determine that you can feel with your fingernail a ridge within the cylinder walls of cylinders 2 and 3.....but with 300 + in the compression test I didn't go further.
Reply With Quote
  #8  
Old 11-18-2013, 10:58 PM
Registered User
 
Join Date: Aug 2000
Location: Houston, Texas
Posts: 325
Quote:
Originally Posted by cooljjay View Post
Was any alternative fuels ever used with the engine? Did you do a valve adjustment after the head was back to insure the gaps were correct?
Yes. I used biodiesel from a dealer which is refined and had the glycerine removed. And I did adjust the valves before the start.
Reply With Quote
  #9  
Old 11-18-2013, 11:03 PM
Registered User
 
Join Date: Aug 2000
Location: Houston, Texas
Posts: 325
When putting in MMO do you configure that cylinder at TDC or at BDC or does it matter?
Reply With Quote
  #10  
Old 11-19-2013, 12:24 AM
Registered User
 
Join Date: Mar 2009
Location: San Diego
Posts: 3,099
Quote:
Originally Posted by airfoill View Post
When putting in MMO do you configure that cylinder at TDC or at BDC or does it matter?
MMO ain't going to work, not with 100psi cylinder.

I turned the engine CW/CCW whichever may I wanted when I overhauled my engine. It is not going to alter the timing as long as you strap the chain to the sprocket wheel. It is NOT going to jump a tooth with the OM60x engine. It is physically impossible. I ain't sure about the OM616 but I would expect it to be the same.
__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.
Reply With Quote
  #11  
Old 11-19-2013, 11:13 AM
Registered User
 
Join Date: Aug 2000
Location: Houston, Texas
Posts: 325
Quote:
Originally Posted by ah-kay View Post
I resurrected a 190D OM601 engine with low compression in cyl 1, also < 100psi, by doing the following.

1) removed head.
2) removed oil pan and pushed all pistons out from below.
3) honed cylinder 1, cleaned ring grooves, load of carbon, replaced rings.
4) It bought the compression back to > 300psi ( cold ).
5) The compression on the other 3 cyl are OK but I cleaned the ring grooves anyway.
6) Now the engine runs like a champ.

I am not sure how easy to do it with a OM616 but you may be in luck as it is cyl 1. It may be possible to push the cyl 1 piston out by removing the lower oil pan only.

Good luck.
ah kay,

Did you have any broken piston rings on your car when you took the pistons out?
Reply With Quote
  #12  
Old 11-19-2013, 11:25 AM
Mölyapina's Avatar
User title not in use
 
Join Date: Oct 2012
Location: Chelmsford, Massachusetts
Posts: 4,373
Quote:
Originally Posted by ah-kay View Post
I resurrected a 190D OM601 engine with low compression in cyl 1, also < 100psi, by doing the following.

1) removed head.
2) removed oil pan and pushed all pistons out from below.
3) honed cylinder 1, cleaned ring grooves, load of carbon, replaced rings.
4) It bought the compression back to > 300psi ( cold ).
5) The compression on the other 3 cyl are OK but I cleaned the ring grooves anyway.
6) Now the engine runs like a champ.

I am not sure how easy to do it with a OM616 but you may be in luck as it is cyl 1. It may be possible to push the cyl 1 piston out by removing the lower oil pan only.

Good luck.
Out of curiosity, why did you hone cylinder #1 instead of replacing the cylinder sleeve?
__________________
"Senior Luna, your sense of humor is still loco... but we love it, anyway." -rickymay ____ "Your sense of humor is still loco... " -MBeige ____ "Señor Luna, your sense of humor is quite järjetön" -Delibes

1982 300SD -- 211k, Texas car, tranny issues ____ 1979 240D 4-speed 234k -- turbo and tuned IP, third world taxi hot rod

2 Samuel 12:13: "David said to Nathan, “I have sinned against the Lord.” And Nathan said to David, “The Lord also has put away your sin; you shall not die."
Reply With Quote
  #13  
Old 11-19-2013, 12:15 PM
Registered User
 
Join Date: Mar 2009
Location: San Diego
Posts: 3,099
Quote:
Originally Posted by airfoill View Post
ah kay,

Did you have any broken piston rings on your car when you took the pistons out?
Not on the OM601 engine I overhauled but on a OM603. There was a lot of coking around the rings and the the same got stuck in the grooves. I do not believe MMO will help with heavy coking. If it is only 100psi then you need to take a look at the cylinder wall. It is loo low to be caused by coking alone. The cylinder wall may have been scored by a broken ring or oval'ed.

Changing the sleeve is a big endeavor with engine out of the car. I left the short block in the car. You only need to hone it slightly to take out minor scoring and imperfection and compression can be restored. This has been my experience on 3 engines, 1 OM601 and 2 OM603.

Good luck.
__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.
Reply With Quote
  #14  
Old 11-19-2013, 01:24 PM
Registered User
 
Join Date: Oct 2012
Posts: 5,429
Did you hear any lower end knocking? A really bad rod bearing could lower the compression result. How much I am not sure and it would have to be a pretty bad bearing to do so.

Might hold together with the cylinder not firing. Cylinder firing the rod is gone in a situation as bad as that. Usually the number one rod lets go on the four cylinder 616 before compression is lost.

Why such a crazy thought? Adding oil to the cylinder gave no upside at all. You had a hundred pound compression with or without it.
Reply With Quote
  #15  
Old 11-19-2013, 03:04 PM
Registered User
 
Join Date: Aug 2000
Location: Houston, Texas
Posts: 325
Quote:
Originally Posted by barry12345 View Post
Did you hear any lower end knocking? A really bad rod bearing could lower the compression result. How much I am not sure and it would have to be a pretty bad bearing to do so.

Might hold together with the cylinder not firing. Cylinder firing the rod is gone in a situation as bad as that. Usually the number one rod lets go on the four cylinder 616 before compression is lost.

Why such a crazy thought? Adding oil to the cylinder gave no upside at all. You had a hundred pound compression with or without it.
No. There wasn't any lower end knocking.

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 07:55 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, 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