I picked up an '89 190E for my kid. It's in very nice shape, only 75K, one owner. There's been a few simple troubles so far - stumble and stall when cold and occasionally dead acceleration from a stop (found a split vacuum line at the EZL) and an intermittent wiper operation (bad fuse).

Anyway, when fiddling around to find what might have been causing the stumbling, I noticed there was no EGR valve. There's an un-machined boss on the exhaust manifold where it should be. I also found that there was no air temperature sensor on the air intake. Again, there's a casting for it in the plastic but it is closed (as in, the hole is completely filled in).

Come to think of it, I'm not sure if there was even an air pump, I'll have to look next time she stops in.

All the auto parts sites list these items for an '89. Is this unusual? Seems to me an 89 should have all that stuff!

The 89 M103 had no EGR, air pump or temperature sensor in the air intake.

gone, probably needs a new Oxygen sensor. If there are no records indicating it was ever replaced recommend replacing the Oxygen sensor. A new one resolved a similar problem with our 1991 300CE when I bought it used 10 years ago.

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Fred Hoelzle

Wow, so there's no EGR, Air Temp sensor or Air Pump. Thanks for the info.

Does this model have a tough time with emissions inspections?

The lady that owned it drove it less than 5K a year so it was always emissions exempt here in PA.

Ferdman, the vacuum leak at the EZL seems to have cleared up the stumbling and it hasn't stalled again. It still has a slight hesitation off the line (not often, but sometimes) particularly when cold. I'll check the temp sensor and maybe the cold engine duty cycle, but I'll also keep the O2 sensor in mind.