Got the head pulled, here's what I saw (617.950) - PeachParts Mercedes-Benz Forum

Jetmugg · #1 12-29-2003, 10:37 AM

Thanks to the help on this board, I got the cylinder head pulled off my '80 300SD. The 6mm bolt and stack of washers trick is invaluable for pulling the pin holding the plastic chain guide.

When I got the head pulled, number 2 cylinder was the worst. Small flakes of aluminum were present on top of the piston, there was visible slight damage around the top rim of this piston, and there was scuffing and adhered aluminum on the cylinder liner.

#3 cylinder was also scuffed, but the others didn't look too bad.

My best guess is that the engine overheated, causing the pistons to expand and come into contact with the liners.

I'll be pulling the engine out ASAP to assess the rest of the damage.

I'm considering all possibilities for repair, including rebuilding what I already have (estimated cost up to $2k for pistons, liners, bearings, gaskets, timing chain, etc). If I could find a good used short block, I'd consider that also. I have checked the local junkyards and not found anything, but I'll keep my eyes open.

I think I'll also post an ad on the classifieds looking for a short block as well.

As always, any guidance is appreciated.

SteveM.

JimSmith · #2 12-29-2003, 11:05 AM

Jettmug,

You may want to try these guys for a remanufactured short block. It is expensive, but I think you get a pretty good product.

www.mercedesengines.net

Good luck, Jim

#3 12-29-2003, 12:42 PM

Try this site.

http://www.remanufactured.com/Mercedes_Engines.htm

Louis

#4 12-29-2003, 01:39 PM

After installing a used engine in my 81SD, that has given me more than a little trouble, I would recommend that you find out exactly how many miles it has (ie look at the odo on the dash from the donor) and how long it sat after being pulled. I got one with relatively low miles, but it had been out on the floor for sometime. That caused lots of problems. Valve springs were collapsed, rings were compressed, seals failed....
Then I would still rebuild my own. Done correctly it will give you a long and happy ride, and for less than repairing another old engine anyway.
I sat with a local tech and penciled out a self done rebuild. Costs go up each time you have a machine shop do something, like assemble the short block. But the worst case was $3000, with a self done assembly and engine pull.
Incidently that would be less than all the $$ I have spent getting the old diesel of mine to run just ok.

lietuviai · #5 12-29-2003, 03:07 PM

Is it really worth spending all that money on rebuilding those older diesel powered M-B's? It seems you can buy another car for way less. Spending $2K to $3K on a rebuild just doesn't really seem like it's worth it. Is this the cost DIY job of just the parts and machining or do you get a fully assembled engine at these prices?

#6 12-29-2003, 06:29 PM

The piston flakes could very well be from ring land failure. I have a souvenir piston that suffered this fate.

The reason that a rebuilt engine is often better than buying a used engine or used car is because you then have a FRESH engine. Buying a used engine or used car is just paying money and taking a chance.

Happy New Year,

lietuviai · #7 12-29-2003, 06:43 PM

While that may be true, the rest of the car isn't. IMO unless you go through the rest of the car as well, it can become a nickle and dime affair. By the time you're done you may end up investing more money than you would have just finding a better and/or newer car with less miles.
Just my 2¢.

JimSmith · #8 12-29-2003, 07:17 PM

I am with Larry on this issue, as usual. I presume the owner of the car has already determined the rest of the car is worth keeping, and now you are looking at the difference between the cost of a fresh engine vs. the cost of an unknown engine that can and likely will be a fresh set of problems. Some may be really nasty and others may be less so, but for the most part 20 year plus old engines with several hundred thousand miles on them are typically not going to be near as reliable as a fresh remanufactured one. While some of these units can go extraordinarily long before failing, those engines usually have been extremely well cared for, and not left standing in uncontrolled conditions in a junk yard for years.

Without a compression test and some evidence the machine works, I would not touch it even if it was free. I have 2 acres of land, and I know my wife would not allow me to store an engine, even an MB Diesel, anywhere on the property if it was not going to stay in one of the vehicles. One dead engine in the car is about all I can keep around the house. And that has a finite welcome.

Good luck, Jim

lietuviai · #9 12-29-2003, 08:32 PM

My issue really wasn't to favor a used engine but merely to ask a question is it worth putting all that money in a car that is only worth maybe $2500 to $3000 at the most.
I realise that these are great cars with a very loyal following but I am relatively new to the M-B ownership experience. I am greatful to all of those in this forum who have provided me with help and advice with my 300D. Without it I may have given up long ago. I really don't want to pi$$ anyone off intentionally either.
~DJ

Jetmugg · #10 12-29-2003, 08:40 PM

Thanks for the input, guys. A lot of good points have been expressed here. For me, it's as much about the joy of working on a project as it is about having another car to drive. Having a fresh project car (In addition to my '63 Nova) is fun and relaxing for me. Neither of these cars really makes sense from a pure economic or practical standpoint, although each has it's own personality and allure.

However, the joy of driving my '63 Nova into town to go to the hardware store, or just to get a haircut and cup of coffee is almost unsurpassed. In similar fashion, driving my '80 300SD will make me feel like the "King of the Town" motoring up and down the highway. (It will also be 10 times more comfortable and safe than the Nova).

So for now, my decision is made - pull the engine and tranny out of the Benz, and start spinning wrenches. I'll keep everyone up to date with my progress.

SteveM.

JimSmith · #11 12-29-2003, 08:51 PM

lietuviai,

No offense taken, as this discussion has no single correct answer - instead there are as many correct answers as there are instances where the issue arises. As you have noted the basic value of an older car should bring into question whether fixing it is worth the investment.

The concept of value is subjective however, and for many on this board, a W123 era, or even earlier, MB Diesel is valued more than its potential resale dollar amount. I try to be pragmatic about these things, but I know, when faced with fixing something with warts I know about, and know the maintenance history on, or rolling the dice and buying another under $3,000 car, I typically default to fixing it. Even when the fixes begin, over time, to exceed the resale value of the vehicle.

I have unfortunately passed this trait on to my kids, as my daughter is now looking to have the rear seal on the 1982 240D with 312,000 miles on it (original engine, head has never been off) replaced. She has driven the car for four years and figures she knows it. She calls other cars in her price range "sketchy" and cannot get excited about learning a new language of mechanical noises to interpret, for what it would cost to fix her old Diesel's rear seal, and all its rust. This is especially true when she figures the "new" car will require an investment to keep running as well, since it was a cheap, used car. In her mind, when she's "done" she would rather have the MB Diesel anyway, so, look for some posts on pulling the engine and replacing the rear seal soon.

Glad to hear the other side of these discussions presented and defended. People asking questions like this one need to hear more than one voice. Thanks for your contributions, and keep them coming. Jim

engatwork · #12 12-29-2003, 09:37 PM

when I purchased the used engine in the 300D ('85). Got it and the tranny for $1000 delivered to the house. The fella I purchased it from advertised it as a 144k mile engine/tranny and based on the way it performs I believe him. It still has the "seal" cap over the ALDA adjustment. I will eventually get around to getting off of my pocket book and getting the pistons/liners that I need to rebuild my spare engine. Looking back on it I wish I had replaced the gasket for the IP before I put it in the car. It has a slight leak where the IP bolts to the block. I did have the foresight to replace the front/rear seal in the tranny prior to putting it all together

.

rwthomas1 · #13 12-29-2003, 09:50 PM

I would look for a used motor. Too many of these cars around with the bodies rusted away or smacked and "totalled" from under the unsuspecting owners. I ran across a running 82 SD in a boneyard last year, 212K. Tranny had died and had bad cancer so there it sat, suspension claimed by someone else but the motor was complete. Started and ran well when jumped, boneyard wanted $250.... my 2cents, RT

Stevo · #14 12-29-2003, 10:24 PM

Jetmugg

I would say, rebuild if you can swing it. I spent close to 3 K on my 616 and don't regret a nickel. Of course I could have gotten allot of car for that money but the rest of my car was very nice and now its a real pleasure having an engine that starts easy and runs good. I learned allot which is really valuable as I plan to stick with these cars a while. You dont know what your gona get with a junk yard engine and most likely your gona spend money on it to get it going . I would put that money on pistons, liners and bearings, if you have time and a place to work.

engatwork · #15 12-30-2003, 07:15 AM

Steve - you reminded me. I did rebuild a 616 engine (new pistons/liners). It was alot less than $3k though. I want to say I had under $1000 in the rebuild.

In regards to my spare 617 engine the cost of the pistons for the 617 were what made me go with a used engine versus rebuilding in th e'85 300D.