Thank you!
You ,guys just saved a couple hundred dollars for me!
I was reading for days to try to figure out what's wrong with my car.
I found it and today I bought the part(only the one) and everything running good again.
I had weird starting,idle,running problems with my '87 190e 2.6.(only 342000 km)
Starting right up cold,but start loose power,rpm after a minute,sometimes even stalled.If it survived the first 5 minutes,I could drive it without problems.At half warm,warm condition was the worst.I had to crank it 30-50 seconds till started up.I was afraid,I wiil ruin the starter.And the fuel mileage!
It was the water temperature sensor! (on the top,closest to the firewall)
Thank you again,everybody!
And a question! My Benz use to use a lot's of engine oil(no leaking,dripping or whatsoever)about a litre at every full tank of gas.Now it stopped,the oil level not changed in the last 3000 km!?
Anybody has a idea what happened?

Did you change oil grade or type?

No.Why?

Previous oil change left the drain plug insuffienctly sealed- no washer?

Different style of driving- high speeds with that motor uses more oil, in my experience.

__________________
'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E

My guess would be that because the engine was over fueling and running to rich, excess fuel was getting past piston rings and thinning oil, this in turn causes the engine to burn oil.