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 02-13-2006, 11:17 PM
Registered User
 
Join Date: Aug 2004
Location: New Windsor, NY
Posts: 57
91 300D cracked 2.5 turbo head.

Hello all. I brought a 1991 300D 2.5 turbo, with 150,000 miles. The car was beautiful. I picked it up two months ago. Had a little knock in it, turned out to be an injector knock. Replaced all 5 injectors and the car ran beautiful. When I had picked it up, it had an injector leak and a leak in the radiator. I changed the water pump, radiator, while I was at it I changed the reservoir and the radiator was changed by the place I got it. The car ran like a top. I got between 30 to 33 miles per gallon on my ride to work. The other day we got a freaky weather here in NY and it went to 65 Degrees. I drove to work and up a mountain. The car warmed up to about 90 degrees. On the way down the mountain, back to 80 and stayed that way all the way to work. That night I started it up and drove home. On the way home I stopped in NJ to get some Diesel (its 20-30 cents cheaper per gallon.) While stopped I saw a little bit of smoke coming out of the back. No bad but I saw it. I smelled it and is smelled like oil. I drove home and saw my smoke coming out of the tail pipe in the rear mirror. The next day. I drove to a funeral about 60 miles away and saw the smoke again. That point I drove it home and took it to Bendz. They told me that it was most likely the head gasket. They told me that it would cost about $700 bucks. Also if I wanted that they could send out the head and have it pressure tested and have seats, valves, and everything rebuilt for another $700. I told them to do it.

I then got the call. They told me that the head had cracked. They also asked me who had changed the head gasket in the past. They told me that it seems to just have been changed. I told them that I had just got the car a few months back and I did not know. Ended up that the head gasket was just done and that the mechanic chiseled the head bolts out and reused them. They also used an after market head gasket. It doesn't end there. The head wasn't torqued right. I was getting bad compression. The timing chain was streched and shouldn't have been re used.

I went by the Bendz, mech and looked at the head. The crack is about a 1 and 1/2 inch crack right by the valves. The head showed where the head was over torqued and under torqued, just by the discoloration, and the head gasket looked real crappy with a copper color. The timing chain....man was it streached. So need less to say the car ran OK for all the problems it had and it is a baby so its costing me....$3000 for a new head that they say is redesigned just for the reason of cracking. It has all the valves and everything. Its in Germany and will be here this week some time. Also getting OEM head gasket and new timing chain. I know the car is only worth about $6000 to $7000, but it drove great with all the problems and the tranny ran well and the suspension was like a new car. The body is great and the interior is like a new car. The car was great, until the day I drove it to benz. Car still drove great. Just wanted to vent. Later.

PS I've owned (3) 123's 300D 1981, 1983, 300TD 1984 and a 1983 240D and a 1984 300SD.

Reply With Quote
  #2  
Old 02-13-2006, 11:26 PM
Registered User
 
Join Date: May 2002
Location: Burbank, CA
Posts: 597
Too bad . Let us know how it turns out. I've spent $$$ myself, 'cause when you're committed ... you're committed.
__________________
'91 300D 2.5 Turbo 330K
'00 VW TDI Golf, 190K
'67 BMW R50/2
'73 Norton Commando Interstate
Reply With Quote
  #3  
Old 02-14-2006, 01:19 AM
sailor15015's Avatar
Reverse lights! Score!
 
Join Date: Apr 2005
Location: Norman, Oklahoma
Posts: 1,184
I understand. I'm staring in the face of a restoration that's probably going to cost me several thousand and at least a year of my life. When its worth it to you, you pay the price to keep it going.
__________________
Seth

1984 300D 225K
1985 300D Donor body
1985 300D Turbo 165K. Totaled. Donor Engine. It runs!!!
1980 300SD 311K My New Baby.
1979 BMW 633csi 62K+++? Dead odo
Reply With Quote
  #4  
Old 02-18-2006, 08:47 PM
Registered User
 
Join Date: Aug 2004
Location: New Windsor, NY
Posts: 57
New Head

Hi all. I went to benz yesterday and saw the new head that came in for my 300D 2.5 turbo. It is a new design. They showed me the old one and then they showed me the improvements. I wish I had a camera. The place where the number one cylinder is, is not cut into. I just had two holes for the oil to go though. If you've seen this head off, you know that there is a 3/4 inch across hole that is about 1 inch deep. It's not there any more. Just the two holes for the oil to go through. The head is just beefier all in all. I wish I knew how to explain it. If they don't have it in on Monday. I will take my camera and take pic's of the old head and the new one. I asked why they redesigned the head if the 2.5 turbo didn't have any problems with cracking. And they told me that they do if no allowed to cool down after hard driving. Also that it IS a common problem with all 124's and 126's with alum heads. They also told me that in my case it was just crappy mechanic work and after-market head gasket. Also reusing the head bolts. I wish knew the mechanic who did this. Well. Thanks for listening.

Rob
Reply With Quote
  #5  
Old 02-18-2006, 09:53 PM
H2O2's Avatar
Empty Vessel
 
Join Date: Jan 2005
Location: Ladeluftkühlerstadt
Posts: 1,429
Yes, the new #22 head for my OM603 has the same improved oil passages. The new OEM Elring head gaskets are also a noticeable improvement over the factory original. My original headgasket was absolutely toast at 211k.

OM602 engines aren't typically prone to cracking, but they'll still do it if allowed to overheat enough.
Reply With Quote
  #6  
Old 02-18-2006, 10:04 PM
lietuviai's Avatar
Registered User
 
Join Date: Mar 2003
Location: SW WA
Posts: 5,741
Just proves the newer diesel MB's were poorly engineered. The 603 is a perfect example. There are have been several head redesigns. I haven't read about the 602's having head problems but then again I haven't been that interested in the newer cars. I've only started reading a little more about them since getting my 603 powered 300D. I won't spend too much time since I'm getting rid of mine once I have it fixed to my satisfaction.
I'd hate to see what's in store for the CDI's.
__________________
DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012
Reply With Quote
  #7  
Old 02-19-2006, 07:48 AM
Registered User
 
Join Date: Aug 2004
Location: New Windsor, NY
Posts: 57
Maybe

I wouldn't say that they are poorly engineered. I would say that the head is. I've owned 126's 300sd and 123's from the 240D and 300D and 300TD. the 3.0 turbo no doubt is all in all a more solid engine but IT also has it's issues. Where I live in NY after it got to about 15 Degrees, the sucker needed to get plugged in. Also no matter what people say, the best mileage I got with my cars was high twenty’s, maybe thirty, but on average it was around 27 mpg. My 300 2.5 turbo, runs like a gas car. It has great pickup off the line. I drove 75 mph with 32 MPG. I did a trip from Ohio to NY where I got 34 MPG, but on average to and from work it's 32 MPG. Oh and it drives like a dream. This is just my opinion.

Rob
Reply With Quote
  #8  
Old 02-19-2006, 08:02 AM
Registered User
 
Join Date: Aug 2001
Location: Milford, DE
Posts: 1,470
Quote:
Originally Posted by occb2
I did a trip from Ohio to NY where I got 34 MPG, but on average to and from work it's 32 MPG. Oh and it drives like a dream. This is just my opinion. Rob
This is not an opinion, its a fact that has been reported by many W124 OM602 users.

I've never heard of a head crack in the OM602 engine but it is certainly possible. For the "cast iron is always better crowd" I'd like to point out that cylinder head cracks on OM61X engines are certainly NOT unknown. I personally had a OM615 engine that suffered a cracked head between the prechamber holes in the second and third cylinders.

I love my 2.5 turbo but I'm certainly looking forward to the day when the CDI's depreciate to the 15-20K level. I'll be all over one at that time - they are spectacular cars.
Reply With Quote
  #9  
Old 02-19-2006, 10:20 AM
Registered User
 
Join Date: Aug 2004
Location: New Windsor, NY
Posts: 57
Same here

My plan is.....I'm a detective in NYC and I have another 6 years to go to retirement. At that point, I will pull out a pension loan that they offer at a great rate, and take a trip to Germany. At that point I will pick my car out with the Mercedes program that they have and ride it around for a week over there. Then send it home and have it here. From what I heard Friday at the dealership, is that they are coming out with the ML in the new CDI 3.5 L turbo. I might just have to get that for the wife and the 350D CDI for myself.

Later,
Rob
Reply With Quote
  #10  
Old 02-19-2006, 11:00 AM
Banned
 
Join Date: May 2002
Location: Blue Point, NY
Posts: 25,396
Quote:
Originally Posted by occb2
I then got the call. They told me that the head had cracked. They also asked me who had changed the head gasket in the past. They told me that it seems to just have been changed. I told them that I had just got the car a few months back and I did not know. Ended up that the head gasket was just done and that the mechanic chiseled the head bolts out and reused them. They also used an after market head gasket. It doesn't end there. The head wasn't torqued right. I was getting bad compression. The timing chain was streched and shouldn't have been re used.

I went by the Bendz, mech and looked at the head. The crack is about a 1 and 1/2 inch crack right by the valves. The head showed where the head was over torqued and under torqued, just by the discoloration, and the head gasket looked real crappy with a copper color.
Sorry to hear of the major trouble. However, I'll take a different tack with regard to the cracking of the head. The previous mechanic knew of the problems with the head and decided to replace the head gasket. The new gasket bought him some time because he certainly didn't want to address the cracked head. It's highly unlikely that he caused the cracked head by over-torquing the head bolts. They will stretch and yield and the torque will falloff quickly.

The aftermarket head gasket is also not the culprit. Some of the aftermarket gaskets are made by the OE manufacturer. I would bet that all of them will go at least 50K miles.......no matter how poor the original construction.

This has the signs of an overheat well before the previous mechanic got into it. And, always be aware, that the passion of most mechanics is to trash others in the same profession..........thereby raising their own status and allowing a blank check for repairs.
Reply With Quote
  #11  
Old 02-19-2006, 01:37 PM
Registered User
 
Join Date: Aug 2004
Location: New Windsor, NY
Posts: 57
Could be

Brian, i believe what you think. But I've seen the evidence. The head bolts were in very bad shape. YOU DON"T REUSE HEAD BOLTS. They did. I've driven the car for over 5000 miles, if there was a crack in the head, it would have shown signs of it. I didn't lose a drop of antifreeze. Also seeing the old head and where the blowby skipped from one cylinder to the other, and the other points where it looked like there was no head gasket on it at all. Also I saw the aftermarket head gasket, looks like a copper/brass mix of sorts, and the Mercedes OEM....very big different. I'm hoping that the guy who sold it to me, who also runs a bendz shop, didn't know of the crack. He is on this site and is a very nice guy and I'm leading to the fact that he didn't know about it. Like I said he works only on Mercedes and has all the parts to do the job right. Just my 2 cents. Or in this case over $3000....LOL. Thanks for your input...Rob
Reply With Quote
  #12  
Old 02-19-2006, 01:45 PM
Banned
 
Join Date: May 2002
Location: Blue Point, NY
Posts: 25,396
Quote:
Originally Posted by occb2
Brian, i believe what you think. But I've seen the evidence. The head bolts were in very bad shape. YOU DON"T REUSE HEAD BOLTS. They did. I've driven the car for over 5000 miles, if there was a crack in the head, it would have shown signs of it. I didn't lose a drop of antifreeze. Also seeing the old head and where the blowby skipped from one cylinder to the other, and the other points where it looked like there was no head gasket on it at all. Also I saw the aftermarket head gasket, looks like a copper/brass mix of sorts, and the Mercedes OEM....very big different.
I can agree that the reused head bolts failed to provide the proper clamp load and the result was a blown gasket. But, I don't accept this error as the cause for the cracked head. Cracks in heads are funny that way. They may occur thousands of miles before you begin to notice any symptoms. My SD had a cracked head. I didn't overheat it. It didn't use any coolant for the first year that I owned it. Then the coolant started to slowly disappear.......very slightly at first. Finally, it was using about 1 pint of coolant every 1000 miles. An oil analysis confirmed coolant in the oil. When the head was removed for a head gasket change, it was found to be cracked.
Reply With Quote
  #13  
Old 02-19-2006, 01:52 PM
Registered User
 
Join Date: Aug 2004
Location: New Windsor, NY
Posts: 57
Good to know. I did find it strange that it went from performing great.....hell it even performed great the day I took it to Mercedes. I just knew that the smoke coming out wasn't normal. Thanks for the info Brian. I always thought that a cracked head showed signs..like overheating or loosing oil or antifreeze. Go to know that these cars can go for a while with a crack.
Later,
Rob
Reply With Quote
  #14  
Old 02-19-2006, 01:58 PM
Banned
 
Join Date: May 2002
Location: Blue Point, NY
Posts: 25,396
Quote:
Originally Posted by occb2
Good to know. I did find it strange that it went from performing great.....hell it even performed great the day I took it to Mercedes. I just knew that the smoke coming out wasn't normal. Thanks for the info Brian. I always thought that a cracked head showed signs..like overheating or loosing oil or antifreeze. Go to know that these cars can go for a while with a crack.
Later,
Rob
Most of the time the crack starts out so small that you can't see it unless you perform a magnaflux or flourescent dye inspection. The amount of coolant loss through such a crack is very small, if any. Then, over time, the thermal expansion cycles of the head cause the crack to widen and, finally, the coolant loss becomes great enough that you see other symptoms.
Reply With Quote
  #15  
Old 02-21-2006, 07:22 PM
Registered User
 
Join Date: Aug 2004
Location: New Windsor, NY
Posts: 57
Wow

Got the car back today. Drives great. I had them change a few things while I was there. There is a new Ratcheting pulley for the alternator that after 96 is standard so I had them put that on. I also had them change the belt tentinor and shock. They changed the timing chain and the IP was tuned. The car is great. I drove it around 60 miles today. What a pleasure. Thanks for listening.
Rob

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 07:45 PM.


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