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 03-08-2006, 05:46 PM
thelazzarusman's Avatar
American Expatriate
 
Join Date: Aug 2004
Location: Toronto, ON, CA
Posts: 59
Moving on to the business of repair (300SDL burning coolant)

Thanks to all who responded to my "I've been had" post. The vehicle's A/C has been repaired succesfully and will go into the dealership tomorrow for the trapox recall, when I can hopefully get all my necessary engine repairs done at little or no cost under the recall

I do have a question about the nature of my coolant burning, if for nothing but a better understanding of the process. The car burns coolant, that's established; however, there is no mixing of engine oil in the coolant reservoir. I suspect there may be coolant in the engine oil, but not vice-versa. Also, although she chugs white smoke sometimes at idle, one she is above the low RPMs, she is smooth and powerful, with no smoke. Most importantly, while I was driving her (which was not long, thanks to my suspicions and your advice!), she NEVER got over 100 C.

Would these symptoms indicate a simple headgasket failure, or an entire block failure? If it's a block failure, why no overheating and the smooth operation above the lower RPMs? This is all quite fascinating to me, which mitigates my anger about being duped in the first place.

Any and all replies appreciated!

DL
__________________
1995 E300 146,000 miles "Celia"--sold
1993 300sd 131,000 miles "Konstanze"--with Mom in Tampa
1987 300sdl 225,000 miles "Frau Grau"
1980 300sd 164,000 miles "Old Yeller"--sold
Reply With Quote
  #2  
Old 03-08-2006, 06:03 PM
dieseldiehard's Avatar
Dieseldiehard
 
Join Date: Oct 2002
Location: Bay Area No Calif.
Posts: 3,983
Quote:
Originally Posted by thelazzarusman
Thanks to all who responded to my "I've been had" post. The vehicle's A/C has been repaired succesfully and will go into the dealership tomorrow for the trapox recall, when I can hopefully get all my necessary engine repairs done at little or no cost under the recall

I do have a question about the nature of my coolant burning, if for nothing but a better understanding of the process. The car burns coolant, that's established; however, there is no mixing of engine oil in the coolant reservoir. I suspect there may be coolant in the engine oil, but not vice-versa. Also, although she chugs white smoke sometimes at idle, one she is above the low RPMs, she is smooth and powerful, with no smoke. Most importantly, while I was driving her (which was not long, thanks to my suspicions and your advice!), she NEVER got over 100 C.

Would these symptoms indicate a simple headgasket failure, or an entire block failure? If it's a block failure, why no overheating and the smooth operation above the lower RPMs? This is all quite fascinating to me, which mitigates my anger about being duped in the first place.

Any and all replies appreciated!

DL
It could be a headgasket, that would be the best thing possible. If not its the head.
read about the cracked head syndrome. The block is not involved unless its a new, never seen b4 problem. Coolant under pressure gets from a cooling passageway into the cylinder
A pressure check with the head off the engine is probably necessary but at that time one can likely see the head gasket and the head and decide which is the culprit
__________________
'99 E320 latest car. '95 E320 Wagon my favorite road car. '99 E300D, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine.
Reply With Quote
  #3  
Old 03-08-2006, 06:04 PM
dieseldiehard's Avatar
Dieseldiehard
 
Join Date: Oct 2002
Location: Bay Area No Calif.
Posts: 3,983
Oh, and don't let the dealer remove the head for troubleshooting this problem or you will be in another world of: "I've been had"
__________________
'99 E320 latest car. '95 E320 Wagon my favorite road car. '99 E300D, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine.
Reply With Quote
  #4  
Old 03-08-2006, 06:09 PM
Hatterasguy's Avatar
Zero
 
Join Date: Nov 2002
Location: Milford, CT
Posts: 19,267
I wouldn't have the dealer do anything they are going to charge you for. If it is the head you can get a brand new 22 with all the trimmings for about $3k.
__________________
2017 Chevy Silverado 1500 LTZ
Mercedes??

"No free man shall ever be debarred the use of arms. The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government."
-Thomas Jefferson
Reply With Quote
  #5  
Old 03-08-2006, 06:11 PM
Diesel Giant's Avatar
Registered User
 
Join Date: Oct 2004
Location: Loganville/Atlanta
Posts: 2,156
Head gaskets can blow several ways. Letting oil in the coolant, letting coolant in the oil, blowing exhaust back into the cooling system and letting coolant into the combustions chamber.

To be sure its coolant burning, it will be a thick sweet smell and very white.
__________________
1981 300D 147k
1998 VW Jetta Tdi 320k
2001 Dodge Ram 2500 141k
1979 300D 234k (sold)
1984 300D "Astor" 262k(sold)
Mercedes How-To and Repair Pictorials
I love the smell of diesel smoke in my hair
Reply With Quote
  #6  
Old 03-08-2006, 07:07 PM
Registered User
 
Join Date: Jul 2004
Location: St. Louis MO
Posts: 160
You most likely have a cracked head and/or blown gasket

I am going through the same thing and in my case there were cracks in #5 and #6 and there had been moisture in all of the cylinders. The car was overheated for the first time 18 years ago and my guess is that it has not run well since(see my post from last week about my 300 SDL autopsy). I think that the cracking head was a dormant condition that went way back but just happened. The oil was clean but the radiator hose was hard as a rock upon starting. It didn't miss at higher RPMs because the cooling system was pressurized to the point that the cracked cylinders couldnt leak enough to screw up combustion. The header tank was black from soot.

I opted for a new "22" head from Metric because the car is worth fixing. In my case I needed 2 exhaust valves, 6 intake valves and all new prechambers in addition to the head for a total of just over $2,500. Add in 6 new glow plugs, a head gasket set, new tappets and a new style (non exploding) vacuum pump and that gets you up to the $3,000 that Hatterasguy is talking about. The springs were all OK and the injectors pop tested out fine.

What you should do is remove the head and look for cracks between the prechamber and exhaust valve. The cracks on mine were almost invisible but they were there. any pitting in the valves and in the ridge area indicates fluid leaks into the combustion chamber. With the head off, you can evaluate the cylinders and camshaft for wear. In my case the cylinders still had the factory crosshatch on the thrust side, the cam was beautiful and the chain had no stretch which goes along with what most mechanics say about the durability of the bottom end of Mercedes diesel engines.
__________________
Tom Hughes
St. Louis
84 300SD
92 300D
86 300SDL
Reply With Quote
  #7  
Old 03-09-2006, 12:02 AM
thelazzarusman's Avatar
American Expatriate
 
Join Date: Aug 2004
Location: Toronto, ON, CA
Posts: 59
I did the radiator hose test

and found the hose soft and squishy after the car had been sitting unused for several days. Is this a good sign?

DL
__________________
1995 E300 146,000 miles "Celia"--sold
1993 300sd 131,000 miles "Konstanze"--with Mom in Tampa
1987 300sdl 225,000 miles "Frau Grau"
1980 300sd 164,000 miles "Old Yeller"--sold
Reply With Quote
  #8  
Old 03-09-2006, 12:07 AM
Banned
 
Join Date: May 2002
Location: Blue Point, NY
Posts: 25,396
Quote:
Originally Posted by thelazzarusman
and found the hose soft and squishy after the car had been sitting unused for several days. Is this a good sign?

DL
You mention that the car "burns coolant".

Are you positive that it does not "leak coolant"?

The soft hose test should be done the next morning after the engine was run. After several days, the pressure may have bled off.

A definitive answer can be obtained from an oil analysis. For $20.00, you'll know what you have. Why conjecture?
Reply With Quote
  #9  
Old 03-09-2006, 12:15 AM
t walgamuth's Avatar
dieselarchitect
 
Join Date: Apr 2005
Location: Lafayette Indiana
Posts: 31,370
by saying burns coolant

i would think it means steam coming out the tail pipe on start up. yes after running a few minutes this will not show. it will still be leakning however. the residual pressure in the system will push some water into the combustion chamber after shutdown until the pressure is gone. then on startup poof steam.

i dont think if there is steam on startup there is any other choice than cracked head or bad head gasket. small chance of cracked block. in any scenario it is head off time.

tom w
__________________
Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins& six speed; I have had about 35 benzes. I am finishing a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual....I also have a Lotus 7 replica autocrosser with a modified K20 Acura engine.
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 04:05 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