Hi, all. I've got a question about the M110 (double-overhead cam I-6, as in the "280" series engines of the early '80's).
We've all heard (and I've experienced 3 examples of) the valve guide problems of the M102/103 engines (from W201 and W124 cars) -- i.e., the guides wear, allowing too much "wobble" of the stems, which reams out the centers of the seals and permits excessive oil consumption.
Well, my newest acquisition has a 1984 M110.994 (about 90K mi.) that uses some oil (300-500 mi/qt -- it varies with the way it's driven) and I'm considering having the valve seals replaced. However, my prior experience with such a fix with M102 and M103 engines was that it was fruitless without also removing the head for valve guide replacement because of their inherent flaw -- prematurely already worn, they will quickly destroy new seals, too.
Question: Does the M110 share this valve guide flaw with the M102/3 engines? That is, if I want to have a reasonably successful fix of the M110's oil consumption, am I again going to have to do the head (to replace guides) as well, or will the straightforward seals' replacments suffice?
I'm planning to go to my local dealer to have them replace the seals -- but I want to know, in advance, whether I should resist (what I anticipate might be) their suggestion to also pull the head for the valve guide job, also. I know it was warranted for my M102/3 engines, but don't know if it's justified for this model, too. I want to be prepared with an answer.
Also, would the M110 engine cost more for mere valve seal replacement than a M102/3? About how much should it be (dollars and flat-rate hours)? And that would include a valve lash adjustment, I suppose ... right? {the M110 doesn't have the self-adjusting features of the M102/3's, I understand}
In advance, thanks to all.

I don't know about how much it will cost, but I'm sure that if it is using that much oil, it does need a valve job soon.
Good luck

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Benzmac:
Donnie Drummonds
1992 500E (very soon I hope
1981 280GE SWB
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

I had a '79 280E for four years and it always used oil in the range that yours does. The word that I got from several respected sources was "it'll go for a long time like that" and unless the performance was affected to just add the oil. I bought mine with 97K and drove it another 35K without oil consumption increasing.

I used Castrol 10-40 in the summer and 10-50 in the winter.

My advice is to save the money, add the oil, and enjoy the car.

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Chuck Taylor
Falls Church VA
'86 300E 5 speed
'95 C220 (wife's car)
'98 Porsche Boxster
Past: '79 280E, '82 300D (18 yrs), '77 240D,
4 250C's