How long will a M127 engine go before needs rebuilt?

[Marrs]

What is the typical mileage I can expect from my '62 220se engine before it needs to be rebuilt? I realize many factors exist that can change the useful life but let's assume it's a typical engine with better than typical maintenance (tho probably typical for users of the forum). I'm specifically talking about the engine life from wear not things like failed head gaskets, etc. and specifically this engine, not Mercedes in general.

Also should the timing chain be replaced at 100,000 miles or really only when it shows signs of noise, wear, etc?

[dirtyharry]

it depends on a lot of factors, I would say mostly you should get upwards of 145K without any real issues except for the chain and possibly the injection pump. it depends a great deal on how you drive, or how it was driven before you got it, if its "lugged" a lot expect excessive valve train wear. and isn't this one of the 3 main bearing early engines? I dont know how much durability these early one's have, if it was a 5 main bearing six, I'd say you might get a little longer life from the bottom end with regular oil changes and depending on the type and age of the bearings in the engine. its not really hard to rebuild this stuff, so longevity is sorta... meh...... keep the revs up, change the oil, adjust the valves.. check for chain stretch..blah..blah..blah.. just drive.. its a W111

[Benz Dr.]

The 220SEb is a 5 main bearing engine. Most are worn out at 100K but many will run longer than that. The head will wear out about twice as fast as the bottom end so a valve job half way though can get you to the 140K mark but not much beyond that.
Typical cylinder wear is about .001 per 20,000 miles. You are allowed .003 wear before it starts to get worn out but I've seen .007 and they will still run OK. I once had a 230SL come in with .015 cylinder wear that barely ran. I had to bore it out to max oversize all in one deal. The guy I bought the pistons from said it was impossible for it to even run but it did. No cylinder was more than 110 PSI and every bearing was nothing more than copper shells.

[kenny33012]

Originally Posted by Benz Dr.

The 220SEb is a 5 main bearing engine. Most are worn out at 100K but many will run longer than that. The head will wear out about twice as fast as the bottom end so a valve job half way though can get you to the 140K mark but not much beyond that.
Typical cylinder wear is about .001 per 20,000 miles. You are allowed .003 wear before it starts to get worn out but I've seen .007 and they will still run OK. I once had a 230SL come in with .015 cylinder wear that barely ran. I had to bore it out to max oversize all in one deal. The guy I bought the pistons from said it was impossible for it to even run but it did. No cylinder was more than 110 PSI and every bearing was nothing more than copper shells.

Out of curiosity, how far do you think the M130 engine will go before it needs a rebuild? I have a 72 250C which I bought in September. The odometer says 21K, so I'm assuming 121K.

[Marrs]

Very good, thanks for the positive reinforcement. I am approaching the first 100k in this car and all seems good but I just wanted to be sure as this is my first vintage Benz (tho not new to old cars). I do all your recommended steps and oil change about every 1,500 miles since I use conventional and to keep the gas out of the oil since the early MFI seems to leak fuel. I'm told this was common and known even when they were built, considered a trade-off to the new technology.

Hmmm, maybe I just need to go drive her right now.

[Palolo]

Originally Posted by Marrs

Hmmm, maybe I just need to go drive her right now.

Don't forget the Italian tune-up...

[Marrs]

Originally Posted by Palolo

Don't forget the Italian tune-up...

I actually did not do that, an excuse for another drive, Grazie!
Varoooooooooooooommmmmm!!!

[Benz Dr.]

Originally Posted by Marrs

Very good, thanks for the positive reinforcement. I am approaching the first 100k in this car and all seems good but I just wanted to be sure as this is my first vintage Benz (tho not new to old cars). I do all your recommended steps and oil change about every 1,500 miles since I use conventional and to keep the gas out of the oil since the early MFI seems to leak fuel. I'm told this was common and known even when they were built, considered a trade-off to the new technology.

Hmmm, maybe I just need to go drive her right now.

I'm not aware of any fuel leaking problems with these engines as an inherent design flaw. If you have a bad injector the engine won't run very well. All three njectors spray at the same time so all injectors in that group have to be very closely matched. Most of them will break at about 200 - 220 PSI and they should be within 7 PSI of each other. I try to group them so that I have the lower ones in one set and the higher ones in the other set. If you have one injector that leaks or is much lower than the other two in that set, you will find that most of the fuel will try to flow out of that one rather than all three. Injectors for these cars are getting really hard to find andare quite exspensive as new parts.
You should also have the distributor blocks checked for even flow. They can plug up and look like injector problems when it's really the block that's plugged up. A lot of people aren't aware of this and the car never runs properly. The injection pump can be set to TDC or BDC although I prefer TDC.

[cth350]

Mercedes don't like to sit in the garage. they need to be driven on a regular basis to keep them happy. For your MFI system, there are some basic setup steps required to get it to work well (and to undo the basic screw up steps many mechanics do to make it run when they don't know what else to do, but I digress).

-CTH

[wbain5280]

The M127 is a 4 main bearing engine. Later M129 and M130's are 7 main bearing.

[Marrs]

My injection system is perfectly tuned after several months of effort, bribes of pastries to my mechanics and some fairly serious cash thrown at the car. I read the fuel seeping issue somewhere in a period article I believe, I will link to it if I find it as I know it is a heavily debated topic.

Thanks Warren, I thought this was a 4-bearing engine but good to have confirmation. This may be the forebearer to the other types but it's still a but "rustic" if I may say so without demeaning the engineers.

[bwostosh]

All good advice,
Great reving fun motors with a 4speed,
can run full throttle in third gear.
If valve stem seals leak, replace them and swap a chain in now.
Check compression, drop sub-pan and clean, adjust valves.

Then run it until the smoke gets too much out the back,
or
oil pressure goes below 15 at idle,

This is a serious one which cost me,
the cam and bearings wiped out real quickly.
Rod started knocking and headed south quickly.
Had to grind crankshaft etc.
don't let it get this far gone.

Now I have spare m127 motors, heads, MFI's etc.
far easier to have the spare motor rebuilt and ready to install
than do patch-up on a motor installed.

[Benz Dr.]

The 220SE was highly modified to make the 230SL - they are both M127 engines. The 230SL was modified to make the 250SL/SE by stroking the crank. Then the 250SL was modified to make the 280SL/SE by making the bore larger.
In all cases, the basic block dimensions remain the same as far as outer lenght, width and height are concerned. Many parts are interchangable if you know what to look for.

[Marrs]

Originally Posted by Benz Dr.

I'm not aware of any fuel leaking problems with these engines as an inherent design flaw.

I finally found the reference I was speaking about. It pertains to the 300sl engine (M198?) which I do realize is similar but not the same as the M127/M180. I was under the impression that the same issues held true, at least for the early W111 cars like mine, #69, that used the earliest versions of the Mechanical Fuel Injection and not the electric version. I certainly could be wrong but this was my reasoning behind the fuel in my oil.

From the Wikipedia 300 SL page:
"The engine's maintenance requirements were high. Unlike the current electrically powered fuel injection systems, the mechanical fuel pump would continue to inject gasoline into the engine during the interval between shutting off the ignition and the engine's coming to a stop; this gasoline was of course not burned, and washed the oil from the cylinder walls and ended up diluting the engine's lubricating oil, particularly if the engine was not driven hard enough nor long enough to reach a temperature high enough to evaporate it out of the oil.

Exacerbating the problem were the large oil cooler as well as the large volume of oil (10 liters), both oriented more to racing than to street driving, which virtually guaranteed that the oil would not reach a high enough temperature. In practice, many street drivers would block off airflow through the oil cooler, and the recommended oil change interval was 1,000 miles (1,600 km)."