75? 280C question - PeachParts Mercedes-Benz Forum

davestlouis · #1 02-07-2006, 09:14 PM

OK, I was finally able to talk to the owner of the 75? 280C that I had been eyeballing for weeks. He claims it runs OK with the exception of the fact that the oil pump is going bad...he is a mechanic and says the lifters started getting noisy, so he shut it down. No lower end noise. He also said he's not a Mbz mechanic but he understands that changing the oil pump is a horrible job on this engine. Any input is appreciated...
1. is the enigne toast, given the limited info we have?
2. is changing the oil pump really that bad?
3. I offered him $125 for the car...what do you think? It's chalky, faded red, has tex interior...the covers are OK but the pads are shot, no sunroof, rusty fenders but otherwise little visible rust.

davestlouis · #2 02-07-2006, 11:17 PM

Crap, I was sort of hoping it was horrible news, so I could walk away from this with a clean conscience...although it could still be horrible news, depending on what's really going on with the engine. It sounds like this "mechanic" doesn't know doodly squat about this engine. I'm inclined to roll the dice on this one, but the seller won't commit until the end of the week. I suspect if I wave cash under his nose he'll go for it. Good thing I can put these cars at my office, my blushing bride might lose her mind if she sees another car join the fleet.

250 Coupe · #3 02-08-2006, 12:42 AM

Could be timing chain noise. Not good if it lets go while driving. Not to hard to change it and the rails.

The chain is tensioned by oil pressure pushing on a rail. He may be thinkimg that it's lifters rather than the chain.

On the other hand, it could be a con rod about to go. The first MB I owned "made a noise and then it stopped". I'm thinking that the con rod sticking out the side of the block might have been the problem.

Michael

Mark DiSilvestro · #4 02-08-2006, 08:17 AM

The early M110 twin-cams did have problems with excessive cam and follower wear, leading to a diesel-like clatter from the valvetrain. The one I repaired, many years ago, needed new cams and followers. The replacement cams from Mercedes had two fewer bearings each and required plugging the oil ports to the unused bearing holes in the cam housing. I presume this was to reduce oil starvation at the cam lobes and followers.

Happy Motoring, Mark

ctaylor738 · #5 02-08-2006, 01:51 PM

For a buck-and-a-quarter, it's hard to go wrong.

The chain is pretty much bullet-proof. It does sound like it has worn cam lobes, and that is a major expense and pain because you need to either pull the cam box or get the front of the engine up to remove the cams. They are hard to find used in good condition.

davestlouis · #6 02-08-2006, 08:43 PM

If I understood him correctly this was not an on-going noise, just something that started suddenly and he shut if off...he diagnosed lack of oil pressure as the culprit, but who knows? I figure I can't get hurt too badly for $125...we'll know by Friday if the deal is going to fly.

Mark DiSilvestro · #7 02-08-2006, 10:47 PM

Awhile back, I saw an M110 twin-cam with low oil pressure. Turned out the screen on the oil pump pickup was clogged. It was relatively easy to clean up and restore pressure. Maybe you'll get lucky.

Happy Motoring, Mark

ctaylor738 · #8 02-09-2006, 08:01 AM

That was my Blue Whale, a 1978 280SE. A great car financially. For $200, I got good rims and tires, rebuilt alternator, new rotor/cap/wires, complete CIS setup with good injectors, cylinder head with cams etc, and working climate servo. Then I traded it for $100 in parts TBD to a recycler.

BTW - I have a perfectlly good M110 oil pump that is yours for the cost of shipping it. I will even through in a pan gasket.

davestlouis · #9 02-09-2006, 07:41 PM

Thanks Chuck...if I wind up with the car I may take you up on the pump offer. I should know either Friday or Monday about the car.

davestlouis · #10 02-09-2006, 10:06 PM

I was just going on a verbal description from the seller...I truly don't know yet what's really going on. This seller operates a mechanical shop, but tends to deal with little old ladies driving early 90's Olds Cieras and the like, and imports would not be the norm for this shop. I work in the bodyshop of a multiline luxury dealership and have access to an employee discount and several tech's in service who will give me good advice on these older Mbz cars. I really need to go to Kansas City this weekend and dolly a W114 parts car back that I bought on ebay several weeeks ago, so I may not talk to the seller of the 280C until after the weekend.

davestlouis · #11 02-25-2006, 11:03 PM

update...the seller has been absolutely unresponsive, I've left 2 messages with one of his minions, no call back. My x-father-in-law has an office in the building next to this shop and he says the seller is a flake and something of a crook, so perhaps it's a blessing that he doesn't seem interested in selling.

Mark DiSilvestro · #12 02-26-2006, 09:50 AM

It's funny how used car dealers (and many others) think any old Mercedes is a priceless classic. A few years ago, I looked at a dirty, shabby '74 280 sedan at a 'hole-in-the wall' used-car lot. Underhood was a Mickey-Mouse mess of patched hoses and wiring, but the body looked solid and it ran well enough. The guy wouldn't budge off of $4000 - for a sedan!

Happy Motoring, Mark

300SDog · #13 02-26-2006, 10:57 AM

Also masters of disguising disasters..... Oil Pump and Oil Pressure problems can *evolve* over period of 40k miles or so, telling us the twincam 280 has probly been running on low OP for 1/3 of its life.

And why did oil pump gears wear down? Sounds like dirty oil never changed...... the most common of piss-poor maintenance practices.

Whatever you do, sure as hell dont touch that car without at least visually inspecting camshafts and rocker arms. Worn out lobes and rockers will be really obvious. You will see hard metal surfaces worn down with darker, softer core metal appearing on rocker surfaces and lobes will look rough. If you see this - run away.

davestlouis · #14 02-26-2006, 01:19 PM

shoot, now I have money burninga hole in my pocket...I ran an ad in craigslist locally, looking for 60's and 70's M-B cars for sale...got a message about a gray market 450SE, 1979 model. What should I look for on a gray market car? It's apple green with tan velour, sunroof, bundt wheels, little bumpers.

Mark DiSilvestro · #15 02-26-2006, 03:51 PM

Things to watch out for on grey-market cars -
If your area requires periodic safety or emissions inspections, it may be impossible to pass or register the vehicle without the EPA waiver documents that exempted many privately imported grey-market cars from catalyctic converters and other emissions equipment, or proof that the required emissions equipment was properly retrofitted (though on a '79, antique vehicle registration may get around the inspection requirements).
Also have heard on the Forum from one member whose auto insurance company threatened to cancel ALL his vehicle policies if he didn't get rid of his grey-markt 230CE! So check with your insurance carrier.

Happy Motoring, Mark