W115 Needs Rebuilt. What am I in for cost wise? - Page 2 - PeachParts Mercedes-Benz Forum

moon161 · #16 12-19-2016, 12:43 PM

I have a W123 616.912, late cam. good power when last driven. I'm in buffalo NY. It has been run on a 2 tank wvo system.

PM if you're interested.

bipolardave · #17 12-19-2016, 12:55 PM

Thanks for the advice so far, all.

My 240 isn't a show car by any means, but I've thrown enough time and money at it to pick up a trophy or two at small, local car shows. I also have receipts going back 40 years and some from the second owner. I even drove it on a 1,000 mile round trip so that the original owner could see it once more. Suffice it to say that there's some history that you don't find everyday with these cars. So if there's a prime candidate for keeping on the road, I think this is it.

The desire to keep it as original as possible kinda rules out an engine swap, regardless of the benefits. Besides, I like the gorilla knob. It gives it a bit of nostalgia and provides some degree of theft deterrence. lol

Anyway, I've already mentally prepared myself for an engine rebuild. Parts and expertise are disappearing so, to my mind, it's better (and cheaper!) to do it now rather than patch it up (if even possible) than wait another 5-10 years.

t walgamuth · #18 12-19-2016, 01:02 PM

Quote:

Originally Posted by barry12345

I was sitting here wondering if the compression numbers done in a static fashion where bad enough to cause your missing symptom. The return tube from the vacuum pump does not have oil in it either? Common oil burning problem on these earlier engines.

At running or dynamic rpm the effective cylinder compression comparisons may be different. Your oil consumption is very excessive for the lower blocks expected normal condition at that milage as well.

Almost sounds like the overheat was so bad the piston rings may have lost their tempering. Anyways I would be tempted to get a newer 616 engine to get away from your type of injector pump. A little more horsepower as well after about 1981?

I believe you can still find really solid 616 engines still out there. The newer engines with minor modifications go in pretty easy. You just have to be pretty selective in what you choose as a used engine.

Otherwise I would pull the head and have a look at the crosshatching and general bore conditions.There are things here that do not add up properly.

Do not neglect the simple check of backing off each injector line when the engine is missing to locate the cylinder that is not firing properly. I would want things nailed down a little better before deciding on a course of action.

Since he said the problem started after a valve adjustment that was not necessary I immediately thought to look at the valves. 250 is not that bad either. My book says 220 for reliable starting....cold.

86-300sdl · #19 12-19-2016, 05:20 PM

Quote:

Originally Posted by bipolardave

Thanks for the advice so far, all.

My 240 isn't a show car by any means, but I've thrown enough time and money at it to pick up a trophy or two at small, local car shows. I also have receipts going back 40 years and some from the second owner. I even drove it on a 1,000 mile round trip so that the original owner could see it once more. Suffice it to say that there's some history that you don't find everyday with these cars. So if there's a prime candidate for keeping on the road, I think this is it.

The desire to keep it as original as possible kinda rules out an engine swap, regardless of the benefits. Besides, I like the gorilla knob. It gives it a bit of nostalgia and provides some degree of theft deterrence. lol

Anyway, I've already mentally prepared myself for an engine rebuild. Parts and expertise are disappearing so, to my mind, it's better (and cheaper!) to do it now rather than patch it up (if even possible) than wait another 5-10 years.

Nice!!! Kind of fun to be at a point in life to think that way.
It's a cool car & story for sure...kind of "priceless". Whatever that is...it is. I look forward to your build.

bipolardave · #20 12-19-2016, 06:10 PM

Quote:

Originally Posted by t walgamuth

Since he said the problem started after a valve adjustment that was not necessary I immediately thought to look at the valves. 250 is not that bad either. My book says 220 for reliable starting....cold.

That was 250 psi wet. If my previous dry readings are any indication, cold and dry compression would probably be 200.

I generally don't have a problem getting it started, even now. Without using the block heater, I set the fast idle and manually glow it for 45 seconds or so. It will typically light off after 3-4 seconds of cranking. The idle is super rough, though. The car shakes and belches smoke, unlike before, and the idle never smooths out. On low idle it's struggling to just stay running. It does, however, smooth out at highway speeds and is almost unnoticeable save the occasional hiccup.

barry12345 · #21 12-20-2016, 01:09 AM

I think I know where you are coming from. In a real rebuild with a little good fortune you may not need pistons or liners. Not a certainty. Yet if the short block only has 130K on it there is still a chance.

To me in your situation it is impossible to even guess what the cost will be. Until that engine is knocked down. I would be hoping that the rings just got cooked in the overheating.

It takes a lot to cook them in a diesel but it can happen. What oil pressure are you observing at full operational temperature at idle? A solid two on the gauge would be nice.

bipolardave · #22 12-20-2016, 08:12 AM

Quote:

Originally Posted by barry12345

It takes a lot to cook them in a diesel but it can happen. What oil pressure are you observing at full operational temperature at idle? A solid two on the gauge would be nice.

Pegged high at high idle (40 psi?) and it drops to 30(?) at low idle once warmed up.