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 09-19-2008, 01:15 AM
Registered User
 
Join Date: Aug 2006
Posts: 41
300SDL in the shop...need some insight...

Alright, here is the scoop...

I have an 87 300SDL and I love her. She has been a great car at 160k miles and the #14 head.

Over the past year it has developed blue smoke and a rough idle. In my quest to trouble shoot it I bought some bosio nozzles and installed them. Upon starting the car the idle was worse and it was dumping an unholy amount of blue smoke out the back. it was bad, and I felt like ****, I thought I had killed my baby...

I rebuilt the injectors again, retorquing them just to make sure I didn't screw them up (a few were leaking, so I cleaned the hell out of em).

Reassembled, got everything back together and it was still bad, althought not as bad as before.

I finally came to terms with the fact that I probably had bitten off more than I should have been chewing at the time, messing with my daily driver, so I took her to the mechanic of a trusted friend and merc owner.

He replaced my injectors with rebuild bosch units (boo, awful Indian made garbage) and told me that it idled better, but it still wasn't right. He says that the car drives great on the highway, it just is idling terribly (misfire on one or two cylinders).

He checked the compression on all the cylinders and all were around, iirc, 325 or more PSI...The car isn't consuming coolant at all or smoking white. It is, however, with an increasing apetite, consuming oil.

He thinks that it needs a valve job, and agrees with me that the head probably isn't cracked.

I am really leaning towards the side of blown head gasket up front...either way, if it is the head or the head gasket, the cylinder head needs to come off...

What do you guys think? Did the bosio nozzles give the car the right spray pattern for just long enough to fully destroy the head gasket up front? Do I need to rebuild the head? Is it cracked? Do I just need to cut my losses and get a 300D? Does this guy not know what he is talking about (he keeps referring to it as electronic injection...thinking of the OM606 perhaps?)?
Reply With Quote
  #2  
Old 09-19-2008, 08:53 AM
dannym's Avatar
I'm not here
 
Join Date: Oct 2004
Location: Deltona, Florida
Posts: 2,360
In my opinion if it was already smoking the Bosio nozzles probably didn't hurt or help, the damage was already done.

Has the car ever overheated that you know of?

I can't imagine pulling the head off to be too difficult.

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
  #3  
Old 09-19-2008, 10:31 AM
babymog's Avatar
Loose Cannon - No Balls
 
Join Date: Jan 2006
Location: Northeast Indiana
Posts: 10,767
If the compression test was good, it doesn't need a valve job.
__________________

Gone to the dark side

- Jeff
Reply With Quote
  #4  
Old 09-19-2008, 10:34 AM
Registered User
 
Join Date: Aug 2006
Posts: 41
The car has never ever over heated. That is the other reason I am straying away from the cracked head.

I really really really think that it is the head gasket...
Reply With Quote
  #5  
Old 09-19-2008, 10:56 AM
Registered User
 
Join Date: Aug 2006
Posts: 41
To further elaborate...Doesn't the rupture happen between cylinder #1 and an oil gallery passage on the head, which would necessarily cause the compression to drop, but the oil pressure would begin to fluctuate?
Reply With Quote
  #6  
Old 09-19-2008, 03:46 PM
Registered User
 
Join Date: Jul 2004
Location: St. Louis MO
Posts: 160
Pull the head

If your radiator hose doesn't get hard when you first start it up and if you don't have black stuff in you radiator tank then you probably do not have a cracked head. It sounds like a head gasket problem to me and you may have oil leaking past the seals down the guides. As you know, they redesigned the head and gasket several times and one of the modifications was to fix the oil leak into the front cylinder.
If you are not going to do the job yourself, it is going to get expensive enough that you will be upside down in the car. If you are going to do the job yourself, you can probably come out OK.
It is not too tough to remove and reinstall the head. While you have it off, you can see what your cylinders look like.
If you are going to keep the car, you might look into sending it off to Metric to get the head done. Call Mike and he can give you an estimate of what to expect. You could also check with local machine shops but be careful to get someone who knows what he is doing.
I'm not sure what the mechanic means by electronic injection. The electronic diesel system did not come until 1990 so the only electronics on your car are a few vacuum control valves. The EDS system in the 90s cars consisted of a computer that controlled boost and idle but the injection was still mechanical. No electronic injection until the CDI (common rail) models came out a few years ago
__________________
Tom Hughes
St. Louis
84 300SD
92 300D
86 300SDL

Last edited by hughet; 09-19-2008 at 03:55 PM.
Reply With Quote
  #7  
Old 09-19-2008, 05:20 PM
Phil's Avatar
Registered User
 
Join Date: Dec 2004
Location: Sonoma County, California
Posts: 1,062
If you have 325 psi at all cylinders I can't imagine there is a bad head or gasket so I wonder if the valve guides are letting in oil before the valves seat or if oil is being let into the air side of the turbo some how.
__________________
1983 300SD
200000miles
Reply With Quote
  #8  
Old 09-19-2008, 06:03 PM
Registered User
 
Join Date: Nov 2004
Location: Nova Scotia, Canada.
Posts: 6,510
Getting nearer election time. I vote for a breech of the head gasket in number one to the oil passage. You should be able to prove it by examining the built up carbon on the number one injector in comparison to it's neighbours. Or perhaps it is wetter than the others. You have been burning oil long enough for a difference to present itself.

The cylinder might even be a little wet if oil consumption is high enough. Might also be reflected in more wetness or buildup around the number one exhaust port than the other cylinders.

Most cracked 603 heads primarily deal with coolant contamination issues. Or as mentioned on site fairly often it seems to be the common symptom. I have no experience personally with those heads.

The poster who mentioned failure of the turbo bearing seals allowing the engine to ingest oil is a slight possibility. Yet I feel that would not cause the engine to run rough. Number one cylinder on the otherhand with all the additional oil might. On severe gasket failure at that location. Removing #1 injector and sometimes oil misting is produced from that cylinder if engine is started.

The other important issue is repairing the car yourself. If counting on paid mechanical shops continiously these cars are not a good proposition in my opinion. Really the only way to grow your own self confidence is dive in. Once past the threshhold many people actually enjoy themselves.

Last edited by barry123400; 09-19-2008 at 06:21 PM.
Reply With Quote
  #9  
Old 09-19-2008, 08:56 PM
babymog's Avatar
Loose Cannon - No Balls
 
Join Date: Jan 2006
Location: Northeast Indiana
Posts: 10,767
One thing to note, regarding your original post, is that the car is consuming oil, not coolant.

The head cracks typical of the original head design are between the combustion chamber and the water jacket, nothing to do with oil. The water can/will become contaminated with oil or soot from this eventually.

The breach in the gasket is as mentioned, typically between the timing chain cavity and the front of #1, and I've also seen mentioned in the FSM oil leaks at the rear of the rear cylinder on the exhaust side where the gasket can tear. I'm not sure whether the latter failure affects all early 60x engines or just the 601 however.

I too vote for the head gasket. It is possible that this will lead to pressurizing the crankcase and forcing oil into places it shouldn't be, there was an earlier discussion about this also, I can't remember the outcome, but it seems like it did something nasty in the end like fill the intake with oil to the point where it could hydrolock 2 or 3 and damage a connecting rod.

Time to pull the head. Removing the head isn't a big job, even I can do it, ... but re-installing it correctly is. Be sure that it is at a competent shop so that you don't fall victim to the "it was broken when we took it apart" excuse for screwing up the job.
__________________

Gone to the dark side

- Jeff
Reply With Quote
  #10  
Old 09-20-2008, 09:41 AM
Registered User
 
Join Date: Aug 2006
Posts: 41
The more I think about this the more I want to do it. I am new to doing engine work (I'm 19) but I really think I can do it if I'm careful enough. The only real hardcore engine work I have done is rebuilding (and I mean rebuilding) a 1950 ford 215 inline six. Granted this is quite a bit different, they are still bolts being turned none the less, I just have to turn them just right and in the right order...

Can the head be removed without removing the cam? I recall there being some special tool to lock the cam gear in place so I don't have to retime everything.

If I do this myself I am going to do the timing chain as well...

Thanks guys! This forum is awesome. If it weren't for all you guys' help I probably wouldn't have turned into the massive car nut I am today...
Reply With Quote
  #11  
Old 09-20-2008, 05:11 PM
sixto's Avatar
smoke gets in your eyes
 
Join Date: Jun 2000
Location: SF Bay Area
Posts: 19,678
The cam has to come off because there are head bolts covered by the cam towers. No special tools needed. Don't move the crank sprocket while the cam is out and you don't have to worry about cam timing.

Make sure you have a good manual because there's a right way and many wrong ways to remove the cam. Some wrong ways result in the cam snapping in two pieces.

Sixto
87 300D
Reply With Quote
  #12  
Old 09-20-2008, 08:05 PM
Registered User
 
Join Date: Aug 2006
Posts: 41
Quote:
Originally Posted by sixto View Post
The cam has to come off because there are head bolts covered by the cam towers. No special tools needed. Don't move the crank sprocket while the cam is out and you don't have to worry about cam timing.

Make sure you have a good manual because there's a right way and many wrong ways to remove the cam. Some wrong ways result in the cam snapping in two pieces.

Sixto
87 300D

Mmmmk...

Problem with the manual is that my CDs freeze up my macbook and I don't have access to a PC...

Are the PDFs available anywhere online or could someone email it to me?

I want to give it about 20 good reads before I even think about doing it myself...
Reply With Quote
  #13  
Old 09-21-2008, 12:11 AM
sixto's Avatar
smoke gets in your eyes
 
Join Date: Jun 2000
Location: SF Bay Area
Posts: 19,678
The CD manuals are just a collection of poorly scanned paper manuals in PDF form. Steve Nervig put together an index of the manual you can use to identify the section of the manual to open directly on your PC, bypassing the goofy UI MB put in the CDs.

http://www.benzworld.org/forums/w126-s-se-sec-sel-sd/1395058-service-manual-index.html

There are electronic/HTML versions of this list with links to PDFs you copy to your PC, also bypassing the goofy UI.

Sixto
87 300D
Reply With Quote
  #14  
Old 09-21-2008, 12:14 AM
sixto's Avatar
smoke gets in your eyes
 
Join Date: Jun 2000
Location: SF Bay Area
Posts: 19,678
Forgot to mention - the sections provided in the index correspond to filenames. The folder structure is somewhat intuitive. The files will be something like ..\programs\engine\602-603\01-415.pdf for removing the cylinder head, for example.

Sixto
87 300D
Reply With Quote
  #15  
Old 09-21-2008, 01:39 AM
Registered User
 
Join Date: Aug 2006
Posts: 41
You guys are awesome!

I really think I can tackle this thing...just going to read through the instructions a million times. I will feel much better doing this myself and being able to say that I did it myself...

As far as leaving the cam sprocket there... wasn't there some special locking tool to hold it in place while the head is removed or does it just sit there? I am thinking about doing the valve stem seals while I am in there...any other "while you are in there" items that I could/should do at this time?
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 05:08 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page