[W126 Coupe] Re: Hatch and Sons is back !!

[Gerry Van Zandt]

I have owned one 57K local Portland 6.3, and currently have a parts  
car left over from my ownership, plus a partially rebuilt spare 6.3  
motor in my garage at home.

The 6.3 is a nice novelty, as Jonathan said, but not for 99% of most  
owners to try to do.  First of all, you had BETTER have a competent  
mechanic who has worked on 6.3s for a long period of time, close at  
hand.  The car will be spending quite a bit of time in the shop on an  
annual basis.  That being said, a competent mechanic will do you  
right, and as systems are repaired (such as suspension) they won't go  
bad again for years to come.  The 6.3 engine is absolutely  
bulletproof, with top and bottom end going 300,000 miles if decently  
maintained.

The Bosch mechanical fuel injection pumps should be maintained about  
every 125,000 miles, and there are only two places in the US that are  
competent at doing this:  Jerry Fairchild Industries of Redding CA,  
and Pacific Fuel Injection of South San Francisco, CA.  The injection  
pump has its own sump and camshaft, as well as a supply of oil that  
comes from the engine itself.  Cooling is from the gasoline.

The air suspension on the 6.3 has two major weaknesses:  the airbags  
(one at each corner) and the air ride valves, of which there are 4 on  
the car plus a main control valve in the engine compartment.  
Generally the o-ring seals in teh valves go bad with age, and rebuilt  
valves must be purchased and installed.  Only 1-2 places in the US  
supply rebuilt valves, with only about a 50% "take" rate.  You can  
get new Bosch valves from MB but last I checked they are something  
like $3K a set.  The airbags should be replaced every 5-7 years.

The other major problem with 6.3s is the rubber and soft parts:   
motor mounts, suspension bushings, window rubber, door seals, etc.   
It just goes bad and lazy/cheap owners never bother to replace it.

Cosmetically, you typically see that the wood needs redoing, as well  
as the interiors.

The heater levers often get brittle and break....and to do these  
right it is a bit of a DIY job.

A stock US model 560SEC is just as fast as a stock 6.3 (my best with  
my stock 1969 -- pre-smog -- 6.3 was 15.07 seconds in the 1/4 mile as  
compared to 15.1 with the SEC) and has a far higher top speed.  The  
6.3's aerodynamics and engine power limit it to a top speed of 130+  
MPH.  The engine is made for low revs and torque (it has 434 lb-ft)  
and thus, above 3,700 RPM it rapidly starts running out of breathing  
room.  By 4,500 RPM it's pretty much worthless as far as helping  
acceleration.  Compare this to a 500E -- which pulls fully from idle  
to redline, and you see a HUGE contrast.  The 560SEC is somewhere in  
between.

There is a theorem that we have as 6.3 owners, that the "6.3" is  
actually a multiplier of the cost of stock 108/109 chassis parts.

If you're interested you can see photos of the low-miles 6.3 that I  
owned for many years, but sold to a collector in Boston about 18  
months ago:

http://www.ibiz.net/~pmhack/mercedes/6-3693.htm

I'll just tell you all that owning an SEC and a 500E both is a MUCH  
better and funner proposition than the 6.3 and 6.9 (which I also  
owned simultaneously with the 6.3 for about 4 years).  I sold both  
the 6.3 and 6.9 out of frustration with the owners club catering to  
those cars, rather than for financial reasons.  For a period of time  
I actually owned the 6.3, 6.9, 500E and 560SEC all together.  I find  
now that the 500E and 560SEC are all that I need (and in two days,  
the addition of a 1987 560SL with 43K miles on it, for my wife).

If anyone wants or needs more insight into a 6.3, don't hesitate to  
contact me.

An article I wrote on how to find a good car is located online at:

http://articles.mbz.org/buying/checklists/m100/


Cheers,
Gerry




On Aug 30, 2006, at 7:05 AM, mbcoupes-request at mbcoupes.com wrote:

> 6.3's are novel and interesting to drive but can't say I'd ever  
> want to own one..  Between maintenance and the cost of parts the  
> cost of the car is the least painful part of ownership.
>
> That 500E they have was originally for sale over @ RUF..interesting  
> to see they have it now.
>
> Jonathan

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