M103 Best Motor Ever - Page 2 - PeachParts Mercedes-Benz Forum

amg280 · #1 06-18-2009, 12:19 PM

Quote:

Originally Posted by volosong

Ditto head gasket problems. With almost 220k miles on my M103 coupe, head gasket has been fine. However, you do have to replace the valve guide seals about every 75 or 80k miles.

The only thing that would make my car the "perfect" car is replacing the auto transmission with a manual...but the wife said she would leave me if I spent the money to do that. Though decision!

I actually did the opposite. I had an 86 300E with a 5 speed. I found the manual in that to be the clunkiest, rubberized shifter I have ever driven. I found a wrecked 300E and put an auto in it. Im sure mine was pretty wore, but still.

junqueyardjim · #2 06-18-2009, 12:49 PM

Hard to think that someone would dump a five speed out of an 300E. I totally love driving mine, though I do limit my shifting a bit by starting in 2nd usually on flat and downgrade roads. Second gear performance is awesome. The rest of the gears are all very good. I find it a delight to drive - AC is still on R12 and I don't want to change to R134 so I find it a bit warm and have it garaged until cooler weather arrives. Mine is a 130,000 mile W124 with a low mileage 89 M103 I installed last summer. I find it a driving combination that is hard to beat and really enjoyable all around. Mine was a very sloppy shifter, but when I installed the 89 engine I also replaced the bushings in the shift levers and it shifts like new.

pawoSD · #3 06-18-2009, 01:03 PM

Quote:

Originally Posted by junqueyardjim

Hard to think that someone would dump a five speed out of an 300E. I totally love driving mine, though I do limit my shifting a bit by starting in 2nd usually on flat and downgrade roads. Second gear performance is awesome. The rest of the gears are all very good. I find it a delight to drive - AC is still on R12 and I don't want to change to R134 so I find it a bit warm and have it garaged until cooler weather arrives. Mine is a 130,000 mile W124 with a low mileage 89 M103 I installed last summer. I find it a driving combination that is hard to beat and really enjoyable all around. Mine was a very sloppy shifter, but when I installed the 89 engine I also replaced the bushings in the shift levers and it shifts like new.

I would think the A/C would perform better re-charged with R12 than it would being converted to R134....

JimFreeh · #4 06-18-2009, 01:53 PM

[QUOTE=amg280;2227281] I had an 86 300E with a 5 speed. I found the manual in that to be the clunkiest, rubberized shifter I have ever driven. QUOTE]

I've owned a number of manual transmission Benz cars, in fact my first Benz was a manual (59 190SL in 1974).

Without exception, I've found the shifter to be way to insulated and vague.

It's not that I do not like manuals, I currently have 4, it's that the later MB automatics are so nice, that I prefer my Benz cars to have automatics.

Jim

#5 06-18-2009, 01:21 PM

The 124 cars originally on R12 are some of the WORST candidates out there for 134 conversion. There's just not enough reserve condensor capacity.

R12 is coming down in price and plentiful any way.

junqueyardjim · #6 06-18-2009, 01:51 PM

I have a W123 with AC running 134. It pulls hard, and the cooling is a joke. Now our 95 Town Car Lincoln is on 134 since new, 200,000 miles and only occasionally have I had to add a bit of freon. And it will freeze your bottom. I'll keep my fingers crossed on that town Car. But my W124 will have R12, maybe duracool, or no AC, but no 134. But my W124 with a 5 speed is an awesome driver. I think that starting pretty easy in second gear, it will do 0 to 60 in about 6 seconds, and will reach just about 80 mph at redline. It is a flyer! I got that great engine from John Hef. Thanks John!

#7 06-18-2009, 03:17 PM

Quote:

Originally Posted by junqueyardjim

I have a W123 with AC running 134. It pulls hard, and the cooling is a joke. Now our 95 Town Car Lincoln is on 134 since new, 200,000 miles and only occasionally have I had to add a bit of freon. And it will freeze your bottom. I'll keep my fingers crossed on that town Car. But my W124 will have R12, maybe duracool, or no AC, but no 134. But my W124 with a 5 speed is an awesome driver. I think that starting pretty easy in second gear, it will do 0 to 60 in about 6 seconds, and will reach just about 80 mph at redline. It is a flyer! I got that great engine from John Hef. Thanks John!

You are comparing Oranges to Apples with those two a/c's. The MB is a converted system originally designed for R12. The Town Car has an a/c that was DESIGNED for use with R134a. 134 requires more condensor area to make up for the use of a less effective refrigerant.

#8 06-18-2009, 03:12 PM

There is a reason the 400E gets virtually identical fuel mileage. They are the same car. Beyond driving style, the most important factors in fuel consumption are weight and aerodynamics.

Although, I'm fond of my 5 speed 300E and have lots of time in the drivers seat, I don't consider the M103 the Masterpiece engine of all time. It rates reasonably high, but there are lots of modern engines, even some of US design and manufacture that are masterpieces IMHO.

pawoSD · #9 06-18-2009, 03:27 PM

Since this is a thread about the M103.....does the timing chain on a M103 ever need to be replaced or dealt with? I remember reading that since its such a short traveled/simple setup that the chances of failure are nearly 0. Is this the case?

volosong · #10 06-18-2009, 03:37 PM

Quote:

Originally Posted by pawoSD

Since this is a thread about the M103.....does the timing chain on a M103 ever need to be replaced or dealt with? I remember reading that since its such a short traveled/simple setup that the chances of failure are nearly 0. Is this the case?

Purchased my coupe with 75k on it, with full records, from the original owner. Has ~220k now. Timing chain never replaced, and I have it serviced religiously by Enrique at Mr. M.B. Motors. If it needed a chain, he would have told me.

pawoSD · #11 06-18-2009, 03:46 PM

Quote:

Originally Posted by volosong

Purchased my coupe with 75k on it, with full records, from the original owner. Has ~220k now. Timing chain never replaced, and I have it serviced religiously by Enrique at Mr. M.B. Motors. If it needed a chain, he would have told me.

Awesome. Mine only has 139k....so it has a looong way to go yet.

#12 06-18-2009, 04:45 PM

The M103 has very little strain on the chain AND has a ratcheting tensioner. My car just hit 310,000 miles with the original chain.

That said, FREQUENT oil changes, which my car has experienced will add greatly to timing chain life. Lack of frequent changes allows tiny particulate to circulate with the oil that adds significant timing chain wear.

pawoSD · #13 06-18-2009, 05:35 PM

Quote:

Originally Posted by LarryBible

The M103 has very little strain on the chain AND has a ratcheting tensioner. My car just hit 310,000 miles with the original chain.

That said, FREQUENT oil changes, which my car has experienced will add greatly to timing chain life. Lack of frequent changes allows tiny particulate to circulate with the oil that adds significant timing chain wear.

How frequent? I change it every 4k with synthetic Rotella Diesel oil. 5w40....and I use the genuine German filters (Mann or Bosch) Is that a good enough interval?

volosong · #14 06-18-2009, 05:42 PM

Quote:

Originally Posted by pawoSD

How frequent? I change it every 4k with synthetic Rotella Diesel oil. 5w40....and I use the genuine German filters (Mann or Bosch) Is that a good enough interval?

Don't know about Rotella Diesel oil, but the interval is fine.

I have my oil changed every 3750 miles, (plus or minus a hundred or so), with Pennzoil 20-50. That is an even multiple of 15K/30k/60k which are more extensive services. Makes the math easier. I made up a spreadsheet after the maintenance book "expired" with mileage service is due, what type of service, and space to fill in the date of service and any other things that were "fixed" or replaced. I just keep it in the map pocket of the driver's door with the owner's manual and registration in that cheesy clear plastic pouch.

#15 06-18-2009, 06:52 PM

Unless you do a considerable number of short hops, a 4K oil change interval should work well. Using Rotella in one of these engines is not a bad plan either. Flat tappet cam engines need ZDDP additive for cam and lifter life. Todays passenger car oils don't have it due to the vast majority of cars having roller cam followers these days.

Thanks to the latest emissions pressure on diesel engine oil, the ZDDP content in the the diesel oils such as Rotella has decreased. Since, however, this is a sliding follower system, the amount of ZDDP in the latest Rotella should be adequate.

The vast majority of the miles on my 300E have been with Chevron Delo, the Chevron equivalent of Rotella. I personally would NOT run any of the newer passenger car oils in the M103, especially in the super lightweights that so many modern engines successfully use.