I have a 280S, 1969 with a M130 engine. The car is very nice and in almost mint condition. However, it was garaged for about 10 years, with only occasional use on weekends. I inherited the car from my uncle almost a year ago and had to fix several problems, including a new transmission, new exhaust, hoses, A/C, alternator, etc.
Two months ago, I noticed that the car had some coolant consumption. No leaks were found. The coolant was apparently evaporating through the radiator cap. I changed the radiator cap but vapor leaks continued in the form of small bursts which increased over time. My mechanic suggested that I change the head gasket. Since some corrosion was found in the head, it is now been rebuilt, with new valve guides, etc. The valves are apparently in good condition and do not need to be replaced. My concern is that the engine had some oil consumption prior to the head job (1 liter / 200 km). Do you guys think that the rebuilt head will now increase the oil consumption? My mechanic does not believe so. He mentioned that it is not necessary to perform a complete engine job at this point, considering the condition of the engine. He said that I can probably get some more miles from it before rebuilding the entire engine and spending big bucks. Can such oil consumption actually damage or affect the rebuilt head? What do you think?
Thanks in advance.

Who knows? Without seeing the engine, it is a long-distance guess.

I will say that if you plan to keep the car, it will be much less expensive to overhaul the bottom end now, The head is off, the exhaust manifolds, AC compressor, water pump, etc are all disconnected. This is all work that will have to be repeated when you have to rebuild the engine.

Do it once, do it right.

Not that I always follow my own advice.

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Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

Thanks for your advice. I only have limited experience and do not feel confortable doing this type of overhaul by myself. I can only do some minor repairs. I think that you are probably right that it would be less expensive to overhaul the bottom now, but I will have to evaluate with my mechanic the cost of performing a complete engine rebuilt. Based on your experience, what do you think the cost range would be?

Since I live in Venezuela, I will have to check the prices of parts locally. The good thing is that we have plenty of used MB parts and experienced mechanics here. Labor cost is also very low. During the oil boom of the 60's and 70's, Mercedes-Benz had record sales in Venezuela. It even built an assembly plant here in order to satisfy the local market. When oil prices went down, the sales went also down and MB closed the plant. So it is not uncommon to see vintage MB (especially w108, w109, w107, w114 and w116) in the streets of Caracas, some of which are in good conditions. My father owned a 230s fintail for over 30 years (white with red leather interior0. I basically grew up with that car.

Going back to my question, considering that my 280s has a new transmission and that I intend to keep it as a daily driver, it would certainly be nice to have a rebuilt engine on it...

I also own a 1972 250C, manual transmission, which I restored 10 years ago. The coupe is now in very bad conditions (after spending 4 years with my brother...). This is also a very nice car but, unfortunately, is not worth restoring.

Thanks for your input.

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280S, 1969
250C, 1972

Suspect worn valve guides and seals had something to do with oil consumption. Headwork is typical for these engines at/near 125,000 miles. After which, the head usually mates to the block and the engine runs forever.

Visual inspection of the bores should tell your mechanic if piston rings have cracked or rusted in place from lack of regular use, also contributing to oil consumption. Are you sure the engine is not leaking oil at front/rear seals or gaskets at vacuum pump, fuel pump or even the oil filter bracket??

Also, you might ask your mechanic about soft-metal Swedish rings that will not cut the bores...... yet are designed to accomodate older engines where piston clearance to bores are within acceptible tolerances, yet rings are all the engine needs after say - 200,000 miles or sitting dormant for a decade and rusting in place.

No surprise that Venezuela is mecca to vintage MB's..... I've heard of the same phenomenon - perfect condition daily driven Vintage cars - throughout Cuba, Mexico and Central America. It would be great to see street scene of Caracas with several Vintage Mercedes.

Again, without knowing local labor rates and parts prices, it is nearly impossible to estimate your costs.

But, Metric Motors in L.A. will sell you a rebuilt short block for around $2000. Because of their volume and efficiency, this is about the best deal going, so a local rebuild may be more. I would guess 24 hours labor to pull the engine, separate it from the transmission, reassemble with the rebuilt short block, and reinstall. So at $50 an hour, that's $1200. Add another $500 for misc. "you might as well" stuff like and oil pump, timing chain, tensioner, motor mounts as well as gaskets, oil, trans fluid.

The cost of the engine work might be a lot less, though, if the crank and bearings are OK and all you need to do is clean up the cylinders and install new rings.

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Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

280S - just out of curiosity what does a pound of r12 freon go for in your country.

I lived there in the early 80's - Valencia and Caracas and thought it was one of the most beautiful countries I had ever been in.

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Jim

The odometer on the car shows 16500 km. I guess that this means that the car has probably 116500 km (or 216500 km ?), since the odometer resets when it reaches 99999 km.

240Dieselbog could then be right regarding the valve guides and seals. My mechanic said that they have to be replaced but that it will not necessary to put new rings at this point since I can extract some more miles from the engine before performing a full overhaul. He also mentioned that the valves are all in good shape and do not have to be replaced. I will discuss this matter with him today in order to understand what the condition of the bore really is. The engine has no oil leaks and is very clean.

The real major fix that I had to perform was a new transmission 6 months ago. The old one was in very bad shape and started to slip badly. I replaced it with a rebuilt MB auto transmission which I had to adapt because it was not identical to the original one. My 280S is a 1969 automatic German specs version, with the parking gear where you normaly find the 1st gear in auto transmissions.

I believe that the new transmission is the one found on w114 and w116, which has the torque converter. This change has certainly increased the performance of the car.

Engotwork: I will check the current cost of one pound of R12 freon and get back to you on that. I think it should not be more than US$20.

Thanks for your advices. I will let you know what I decide after reviewing my options with the mechanic.

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280S, 1969
250C, 1972

280s,

If the valves are in good condition and the cylinder bore is not markedly worn the engine probably only has 100k or so miles on it. At that milage I would overhaul the head with new valve seals, perhaps new guides and put it back on the engine.

If you started the engine before you removed the head you might have noticed whether the oil pressure came up quickly. If it did then the chance are that the bearings are in good condition and an overhaul is not necessary.

The difference in what you will save by doing an o/h now that you have the head off and what it will cost you later is not very much. Plus the chances are good that you will get many many more miles from the engine as it is now.

I made this mistake on a GM Diesel engine. I spent $1,000 going through an engine that really didn't need it. It was one of those 'I am this far into the engine I might as well to the rest'. Costly mistake. In the end I could have just gotten by with a valve job.

Good luck.

Thanks, Kip Foss. That's what I decided to do, based on the advice of my mechanic. He believes that a complete overhaul is not necessary at this point, provided that valve guides and seals are replaced.
I have an additional question. Since the timing chain is not badly worn, do you think I should change it now? Or should I wait until I overhaul the engine? If it's not too expensive, I will probably go ahead and replace it, considering that it has +100K miles and is 35 years old...

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280S, 1969
250C, 1972

280s

Age won't effect the timing chain but get your mechanic to check the slides. At that age they are probably very brittle. This is another 'might as well' situation. If the slides are bad and the chain doesn't really cost that much then you might as well do the chain while the engine is open.