Buying 1987 124 Turbo ( won't start ) ? - Page 4 - PeachParts Mercedes-Benz Forum

dieseldiehard · #46 02-06-2006, 12:45 AM

Quote:

Originally Posted by Brian Carlton

I have to tell you a story today.

I started the '86 SDL for the first time in about 30 days or so. Clouds and clouds of blue smoke. Ran rough for at least 90 seconds. Usually it clears up faster than this, but, I didn't run the glow plugs long enough.

Yes, the values for the compression are not good. But, again, if you can get the vehicle on the road and drive it for a few hundred miles, you might find that things begin to improve with it. No guarantees, but, if it has been sitting for awhile, it needs a good run to get the rings to seat again and get all the carbon out of the cylinders.

I do believe that David managed to pull the oil pan, but it was very difficult to do. He had to raise the engine quite high to pull it off.

As for the probability of success in terms of replacing rings and bearings, I'll have to defer to someone who has attemped this and was successful. I don't have personal experience with such a task on the 603.

Having just replaced rings in my 603 (famous long rebuild project now completed BTW

)
I can offer some advise: it is not a terrible ordeal and its not too costly if you have a good Indy or aaccess to a lift, as long as the head is off. Dropping the lower pan wasn't hard either and gives a chance of cleaning the gunk that accumulates there and a new gasket too if yours is leaking.
I decided to go the extra step of replacing rings while replacing the head on my '87 300D recently based on the advise of a seasoned mechanic who has done this numerous times. While measuring the cylinders for OOR he spotted a small groove that he said is typical on diesels with over 200K miles on them where rings are worn.
Removing pistons was sorta scary, you have to grind the ridge at the top of the cylinder then push the pistons out from the bottom. You never know if its going to hang up on what lip might remain, and it makes a lot of scraping noise during the process and I was afraid of scratching the cylinder walls but realized it was above the active are where the rings contact the cylinder.

Cleaning the ring grooves is a PITA and I did it in sets of two, over three day stretch because of the smell (lots of liquid wrench) and its hard on the eyes.
You want to use Deves rings BTW. And a Victor Reinz headgasket set.

l felt as long as the head was off and I had a friend able to apprentice me hey the cost wasn't that much over where I was already what with a replacement head, new vac pump, oil cooler and lines (don't ask!) new radiator, fan clutch, water pump, timing chain, tensioner, etc. After its all over now, I can say that I learned a lot plus I now have a good running engine.
I am still waiting to see what oil consumption is as I haven't run thru a tank of fuel yet and I am on dino oil for break in.
I can tell the engine definitely starts quicker than my 603 with original rings and similar miles. I am certain its because of higher compression and I've noticed the same thing when I had a 617 rebuilt comnpletely, they almost start on less than two ticks of the second hand on my watch

I don't have a feel for the smoking at startup issue yet, Brian and sympathize with your experience. I've seen it when I failed to glow the full period but its to remind you its a diesel, maybe? I also think that smoking at start up is a common thing related to the fuel system and idle speed control system on the 603's.

Brian Carlton · #47 02-06-2006, 10:03 AM

Quote:

Originally Posted by dieseldiehard

Dropping the lower pan wasn't hard either and gives a chance of cleaning the gunk that accumulates there and a new gasket too if yours is leaking.

I just wish to note that project was done on the W124. Dropping the oil pan on the W126 is not easy and it requires that the engine be lifted very high in the bay. I've not done it personally, but am relaying experience of others who posted.

rkpatt · #48 02-06-2006, 01:09 PM

I was on the phone with a local independent Mecedes only repair shop looking for parts and got into a discussion about this car . The gentleman on the phone told me that the bottom ends of these engines were weak and it is very possible the PO had a hydrolck situation there may be bent rods and pistons . He told me he has seen some come in running with a practically running sideways in their bores . He said that the cost of new pistons and rods is so high that I would be better off with replacement engine vs rebuilding .

Hopefully my leakdown test later this week will unveil a clearer picture .

Brian Carlton · #49 02-06-2006, 01:17 PM

Quote:

Originally Posted by rkpatt

The gentleman on the phone told me that the bottom ends of these engines were weak and it is very possible the PO had a hydrolck situation there may be bent rods and pistons .

While it's possible that the "sky is falling", the individual that you spoke with doesn't seem to be focused on the 603.961 engine. Based on the results of members on this forum, the bottom end is very robust and rarely will a connecting rod or piston be the issue with them. Naturally, if he is referring to the 603.970 engine, it's a completely different story.

WANT '71 280SEL · #50 02-06-2006, 10:33 PM

I was the gentlemen who dropped the lower pan on his 126 300SDL. It is managable but I would really not have done it if I did not have access to a lift. You have to have the engine jacked up about as high as the transmission tunnel will allow you in order to get the pan to slide out. Then, on top of that, putting the pan back on is a pain because of course oil is still trying to drip on your new clean surface. Guess what, mine leaks. At least I believe it is but I am just going to pull the whole engine this summer and reseal everything. Oil leaks drive me nuts and it is embarrasing to park your car in someone's driveway and have a dark spot left for a year from where your car sat.

Let me know if you have any questions. I do have some pictures on here somewhere I believe that show the engine jacked up using a cork-screw type tool. I also show in the pics where the tool was placed, etc.

Thanks
David

WANT '71 280SEL · #51 02-06-2006, 10:36 PM

If you follow this link I have a couple pictures and give some brief advice that could help anyone interested.

Thanks
David

Partial DIY pictoral of 603 oil pan R&R

rkpatt · #52 02-07-2006, 06:54 AM

Quote:

Originally Posted by WANT '71 280SEL

I was the gentlemen who dropped the lower pan on
his 126 300SDL. It is managable but I would really not have done it if I did not have access to a lift. You have to have the engine jacked up about as high as the transmission tunnel will allow you in order to get the pan to slide out

I have access to a hoist and own a floor jack but not a lift. I want to perform the job with the engine in the car if at all possible . I also would prefer not too do lot of accessory disconnections because of the extra time involved and also the risk of connectors , hoses etc. breaking as everything is working perfectly now .

Any more details on this would be appreciated - Thanks

WANT '71 280SEL · #53 02-07-2006, 10:39 AM

You should then try to find a tool like the one I used. It is for raising engines when they are on a lift. It's really just a big corkscrew with a lever that turns raising the screw. I did not have to disconnect many accessories except for the throttle linkage up top, possibly the fan shroud. Of course remove the motor mount bolts that go up from the bottom. There are very few things that have to be removed in order to get the pan off. The bear is just getting the pan on and off because it is so big and everything is a mess. Also, you are working above your head so your hands do get tired.

Thanks
David

rkpatt · #54 03-03-2006, 06:41 AM

Due to dealing with illness of a family member I am still in the planning stages and still haven't yet gotten to the (pre-head removal and cylinder inspection) leakdown test yet.

Just curious in case the head is shot - I have found a 200k mi well running complete 1987? 190D 2.5 turbo motor in a very cheap donor car not worth fixing up (bad climate control , bad ball joints, bad dash cover,auto trans iffy , mediocre body with a maaaco pt job . Would it be an easy swap ? Is so this might be my best solution as the #22 heads are scarce and very pricey .

Brian Carlton · #55 03-03-2006, 08:04 AM

Quote:

Originally Posted by rkpatt

Just curious in case the head is shot - I have found a 200k mi well running complete 1987? 190D 2.5 turbo motor in a very cheap donor car not worth fixing up (bad climate control , bad ball joints, bad dash cover,auto trans iffy , mediocre body with a maaaco pt job . Would it be an easy swap ? Is so this might be my best solution as the #22 heads are scarce and very pricey .

You don't want to go through that effort. The 602 engine was never installed in the W126, so, you would be on your own as far as all the small details required to physically install it. Transmission/driveshaft issues might be overbearing.

And, when you finally get done, you've installed a low powered engine into a large vehicle and driving it will feel like you're pushing a lead sled.

rkpatt · #56 03-03-2006, 08:21 AM

Brian - I don't know if you saw my later correction post but my car is actually a W124 not W126 - . I couldn't get the edit function to change the title after my initial post . - Thanks

Brian Carlton · #57 03-03-2006, 08:28 AM

Quote:

Originally Posted by rkpatt

Brian - I don't know if you saw my later correction post but my car is actually a W124 not W126 - . I couldn't get the edit function to change the title after my initial post . - Thanks

OK, yes, missed that little change.

For the W124, I don't see any problem with the 602. I offer no technical advice on that body, but, others surely have R & R'd a 602 from it.

rkpatt · #58 03-05-2006, 05:08 PM

I have finally gotten downto doing a quicky leakdown test on the bad cylinders # 3 ( the worst ) and # 6 . No air leakage was heard through either the exhaust or the intake and there were no bubbles in the coolant resevoir . The only place where air was heard was the crankcase on # 3 and maybe the crankcase or the oil return holes on #6. In either event the engines head will have to come off . At this point it look like new rings no manner what the car rebuild in the versus a complete engine rebuild . The only question is whether to bite the $ bullet on a replacement #22 head even if the #14 looks good and the pressure test by the machine shop ( Dover ) is ok .

Hit Man X · #59 03-05-2006, 05:55 PM

Why not look for a good used 17 or 18?