Author Topic: Poll - how many miles before engine rebuild?  (Read 7294 times)

Cees Klumper

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Poll - how many miles before engine rebuild?
« on: September 13, 2003, 00:20:51 »
In one of today's posts, Bill Greffin ('Tobacco') comments about his engine needing some new piston rings at 98,000 miles, wondering if this is normal for our cars. So ... if you know at what mileage your car's engine had to be rebuilt, tell the group. You can distinguish between the cylinder head and the short block (i.e. the engine block itself: crankshaft, cylinders, pistons etc).

Cees Klumper in Amsterdam
'69 white 280 SL automatic
Cees Klumper
1969 Mercedes 280 SL automatic
1968 Ford Mustang 302 V8
1961 Alfa Romeo Giulietta Sprint Coupe 1600
1962 FIAT 1500S OSCA convertible
1972 Lancia Fulvia Coupe 1.3
1983 Porsche 944 2.5
1990 Ford Bronco II

Richard Madison

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Re: Poll - how many miles before engine rebuild?
« Reply #1 on: September 13, 2003, 04:04:12 »
Know about an engine with 75,000 original miles where one spark plug gets oily every few months...the oily plug stops firing unless the plug is changed...understand that oil in the cylinder is a ring or valve problem...yet it has 150 or better compression in each cylinder.

Surpised to see this problem in an engine with relatively low mileage and good compression...
Richard M
1969 280 SL, Tunis Beige, Euro Model (Italy).

ja17

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Re: Poll - how many miles before engine rebuild?
« Reply #2 on: September 13, 2003, 06:26:39 »
Hello,
You some may remember the Blue 1969 280-SL of Bob Fellows at the tech session. Bob is the second owner and has owned the car since two years old. It has 145,000 miles. It has been in continuous use since new.

Bob and the original owner used this car in Club track events for many years, usually two or three times a year. He retired it from competition about ten years ago. The motor has never been rebuilt and does not smoke or use oil. It's oil pressure is like new, it runs cool, it runs great. He did have a valve guide come loose years ago. The head was removed and repaired.
 
Bob religiously changes the oil and coolant on time. In addition, the chassis is lubed on a regular basis and the brake fluid is changed at intervals. The engine timing chain was replaced as a precaution at about 100,000 miles. The automatic transmission and rear end have been trouble free and they have also been serviced at their prescribed intervals.
 
The exhaust system was changed to stainless steel years ago, after several changes with original steel systems over the years. I replaced the front king pins and link pins with sub-frame mounts a few years ago. The original water pump was replaced last year. The clock and heater controls were repaired a while back. The original ignition transistor box failed and was replaced at about 120,000 miles. The original ignition wires and distributor are still fine.

Aside from consumables such as brake pads, motor mounts, flex disc and tune-up parts I cannot recall any other mechanical items which have needed repaired or replaced.

Bob has always tried to drive the car at least 7 miles whenever it is started. This warms and lubricates and dries everything mechanical (brakes, injection etc), allowing all the mechanical systems to reach their warm cycle. The car has been kept garaged winters. The original chrome and mostly original paint is in excellent condition. It has never been restored and is in  excellent condition fot its mileage and age. The engine shows no signs of needing rebuilt.

Joe Alexander
Blacklick, Ohio
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

n/a

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Re: Poll - how many miles before engine rebuild?
« Reply #3 on: September 13, 2003, 08:45:27 »
I know the second owner (from 73 to 96...) had some work done on the cylinders at around 90k miles I believe. Engine runs strong, last time I checked compression, it was 150 accross the board. The previous owner didn't use the car very much.

off topic question: how much is an Ignition Command Unit???
I had to change mine recently and I just want to compare how much I was charged....[:0]

Fabrice
Silver 1971 280 SL
New York City

Naj ✝︎

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Re: Poll - how many miles before engine rebuild?
« Reply #4 on: September 15, 2003, 03:50:57 »
At the Pagoda gathering at Speyer in Germany last month, there was a 1963 230SL with 1.2million  kilometers on the clock. Its still had its original engine and is used regularly by its original owner (and wife).
naj[:0]

naj
'Kloines Scheisserle'
65 230SL
68 280SL
« Last Edit: September 15, 2003, 11:27:42 by naj »
68 280SL

Ben

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Re: Poll - how many miles before engine rebuild?
« Reply #5 on: September 15, 2003, 04:15:29 »
My engine had 122,700miles/198,000km on it when I pulled it. It had never been opened or machined, still had the 81.97mm pistons and standard crank bearings. The head had original guides and the valves/seats were original !

The reason I pulled it was it started to drink oil, I had done 12,000 miles in 6 months, but prior to this it had been laid up for a few years with little or no driving. I think a lot of engines suffer from being reactivated unsympathetically after hibernation. Anyway it had about 4 broken top piston rings, still showed good compression though, and 3 loose valve guides !

The crank was almost perfect save for a few marks, but no scores ! Found a crank link, oil can foil and a chain guide in the sump !

Regards,
Ben in Ireland.
'64 230SL 4sp.

rwmastel

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Re: Poll - how many miles before engine rebuild?
« Reply #6 on: September 15, 2003, 08:40:41 »
These engines can go a long way and put up with a lot of neglect before needing rebuilt.  But to say that an engine should not need rebuilt after 75,000 miles is too general a statement.  What if it was in storage for many years and internal components rusted together?  What if fluids or seals were never changed?  What if broken components were not fixed?  It's not just milage.....


Speaking of engine rebuilds!  When I changed my timing chain at Joe's a few weeks ago, many things were learned about my engine.

 - The chain we removed (stretched to the limit of the chain tensioner) was not a factory original endless chain.  It had a master link.  So, assuming chains last 100,000 miles, then my car must have at least 200,000 miles on it if that was the second chain replaced.  (I have no service history before 1980.)

 - Joe noted that I have old style white valve seals on the valves, but they have been there so long that they are black!  Very old and well used seals.

 - Finally, we removed the lower oil pan and removed the bottom of a main bearing and a thrust(?) bearing.  Both were scored, presumably from what we belive are small pieces of broken chain rail.  I have no idea how many months/years this material has been circulating in my engine.

 - So, with the scored bearings, old valve seals, low oil pressure at idle, and high oil consumption, I'm looking at an engine rebuild as soon as I can get the money.  Who knows what my piston rings and cylinder walls look like!



Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420
Rodd

Did you search the forum before asking?
2017 C43 AMG
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Longtooth

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Re: Poll - how many miles before engine rebuild?
« Reply #7 on: September 18, 2003, 03:32:39 »
Excessive oil consumption, low cylinder pressure (both from valves and rings) necessitated complete rebuild at ~110K miles.  I'm the 3rd owner but I purchased my '67 250SL in August '84 from the 2nd owner who purchased it in '68 from the original owner.  All maintenance was done (since '68) by one local MB Shop, all records of every visit, inspection, repair were available at the shop when I purchased it.  The shop owner and mechanics (Father and 3 sons) were very familiar with the car and it's prior owner (a lady teacher).... and could recall almost from memory what had been done to it over time.  It had never had any major engine or transmission mechanical work done... no valve work, no timing chain, just normal hose / belt replacements, tune-ups, oil changes, lubrications, brakes, shocks, etc....odds & ends that broke or were worndamaged by normal wear & tear.

I put $1000 into it for new tires, hoses, belts, some front susp parts (I forget what off-hand), and drove it for about 2 years with increasing oil consumption and smoking.... fouled plugs cleaned and/or replaced frequently, etc.... decided to rebuild the whole thing with my block and heads, but didn't have the cash laying around to do this at that time.... thought I'd drive it occasionally to warm up the engine now and then, but after the last time I parked it I didn't start or look at it again for nearly 16 years (covered in my garage)... this was unintentional benign neglect... kids needed more attention as they grew (so my time became more limited).... work became an increasing priority as I moved up the ladder, money became more scarce as kids demands kept well ahead of rate of inflation, then their University education costs, increasing maintenance costs on the house.... etc, etc, etc..... so the covered 113 in my garage just sat there for 16 years.  I think I started it once or twice in that time, but that was it.

About 5 years ago I had it painted (stripped to metal inside and out (except for engine compartment).... lead used for the odd dents here and there (there's no plastic fillers anywhere on the car), laquer paint and overcoat with a newer MB color than the original --- but nearly the same shade and color... just a more modern version (metallic) of it more or less, more appealling.  I should have had the windshield removed when I had it painted then, but didn't realize at the time .... so there's a little painting update I need to have done when I remove the windshield, rubber, & moldings to clean it up at the edges where the paint meets the rubber (even though it was a good job, it's less than perfect).  

Then it sat, covered again, in my garage.
 
Two years ago I took it to the same shop it had always been serviced at.... and said --- fix everything up to full snuff.... engine was shipped to LA (Metric Motors) for complete rebuild with my block and heads (both of which turned out to be in perfect order for rebuild)... injection pump sent out for refurbishing and one injector was rebuilt (expensssssssssive!)    

While the engine was out I had the engine compartment painted and detailed to just shy of concourse show condition... but there's still a few clamps that I have to replace with the original types and have replated... otherwise all linkages and other accouterments were replated... I left the Valve cover as is though... clean aluminum, but not polished.

About 80% of the chrome (inside and out) has been rechromed now... a few pieces here and there still need rechroming but unless you're standing within 1 foot of the chrome pieces they look just as good as new.... tarnished, but not pitted.  

Inside redone in original leather materials, colors, wood refinished to original (none of it was damaged... just sun and weather... laminated veneer was still solid).... some of the work was done by a restoration expert, some by me under his tutalege.... both to save me some cash, and to save time in getting things done (his schedule prioritized the 300SL restorations for customers that don't ask what it costs or when it will be done)... so I got the advantage of his expertise and knowledge of what's was done in factory original parts/pieces/methods, etc, plus his teaching me how to take certain things apart and how to get them back-together. I'm actually in awe of how these cars were built and asm'ed, engineered in certain aspects (I'm an engineer, so have an appreciation for the methods used, engineering design, etc).... it was a manual build and asm... labor hours and skills immense in original mfg'ing.  I'm taking care of the things I didn't have done during the restoration as I get time... so the hardtop restoration is the next major job on the list... stip to paint (better paint job than when I had it repainted 5 years ago), replate chrome, new rubber, refurbish wood, & replace the headliner which is stained some around the edges.... why it's stained there and nowhere else is a question....  That and the windshield chrome, rubber and glass (orig. front windshield still on the car.... seem's like it's been thru several sandstorms).  I've still got to replace the beauty-rings and wheel covers (nice, very presentable still, but less than perfect).  Need to replace some front suspension parts yet (originals... rubber getting ratty and relatively ineffective).  Then there's my pesky passenger side mirro on the visor.... still has that one streak down the center so it hs to come out and get resilvered and replace in the visor.  Instruments are fine still.... but the insides of the bezel glass have some condensate markings that I'm bothered by and so need to remove the glass, clean it and replace without wrecking the chrome retaining rings.... and my temperature air flow regulating rings... original plastic, not broken, turn easily and work fine, but the white one is tarnished greyish color now and they all need the edges (with the 'serrated' edges) cleaned right  --- haven't figured out yet how I'll do that right yet.... but think a bristle brush &/or a shaped tool edge with some kind of thin 'pad' material saturated with plastic polish to get into the deepest part of the crevace's might do the trick if I use a microscope... expect tedius.

So, 100K miles give or take 10K is about the level rings, valve guides, timing chains, bearings, and other engine wear parts start needing to be replaced.... of course it depends a bit on how the car was driven and how often oil was replaced, but if driven with any sort of zeal for any significant portion of the 100K miles then it seems to be about the normal limit.  My father owned a '67 250SL (purchased in Southern Italy while he lived there), and he had his engine rebuilt in by MB Stuttgart at about 110K miles... and he drove it with more than a little zeal in Italy and the rest of Europe ... generally at a steady  140 -160Km/hr from Southern Italy to Central Geramany on a 3x - 4x per year basis for a decade... not to mention all over Italy 'racing' the Italiens on the Autostrada... it's an ego thing.  My younger brother drove my father's 250SL while he was in high school (in Italy) and if you remember when you were 16, 17, 18, then you can imagine how he drove the SL (in Italy no less)... so it got some high rev's on a frequent basis for 3 years.... it's a wonder he didn't kill himself, but he did have to call dad in the middle of the night on several occasions when he'ed run it off the road into some field or ditch or down some embankment (going around a curve of course), so the Italien MB dealer in Naples got quite a bit of my father's business (he also owned a '63 190SL roadster).  What I couldn't figure for the longest time is why my father didn't take the keys away from my brother after the 1st incident.... but my brother's 14 years younger than I so I began to understand when I hit 40 something..... my Dad got less uptight about the inevitable as he grew older and wiser... to my brother's benefit.

But I digress as usual.... seems that even hard-driving the engine's good for about 100K miles.... provided oil & filters are replaced and changed on a frequent enough basis... more is always better, it's only a matter of degree.

Anyway, now that our freeway has been widened to 4 lanes in both directions I can cruise to work at 80 - 85 mph, buzz up to 95 when I think the coast is clear (CA Hiway Patrol seems to be somewhat less visible these days in CA... geez, I wonder why???? duh!  I'm sure you've heard of our $38B budget shortfall).  The car feels and sounds best at about 85 - 95... solid, and real responsive.  The acceleration from 75 to 95 is quite impressive for a car built in '67... it doesn't start pooping out (lower acceleration) until I get past 95 moving toward 100.  I'm not saying it's a rocket... my wife's 500SL ('94) is a rocket... I've yet to top it out and I've gone past 135 briefly... how far past I'm not sure 'cause I wasn't about to take my eyes off the road for a quick glance at the speedo to find out.  But the '67 sure get's a lot of attention when I move past slower traffic at 90 or accelerate around a few cars from 80+ to 95 in two shakes of a lamb's tail.          

Speed kills, but what a way to go.

Longtooth
67 250SL US #113-043-10-002163
95 SL500