Did it occur to you that the wrong thermostat was installed?

__________________
Regards

Warren

Currently 1965 220Sb, 2002 FORD Crown Vic Police Interceptor

Had 1965 220SEb, 1967 230S, 280SE 4.5, 300SE (W126), 420SEL

ENTER > = (HP RPN)

Not part of the in-crowd since 1952.

? 80C is about normal....the 12mpg issue does not have anything to do with it running at 80C....it is a sensor issue. The computer is running it too rich.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

Hi guys,

Sorry for the late reply, I've been preparing for a hurricane coming our way (Hawaii) which it appears to be scaled down to a tropical storm now. I didn't get a chance to check the 4-pin coolant temp sensor but will do so tomorrow.

I'd like to check out all the temp sensors and order all the faulty units at the same time to save on shipping but am not sure how many there are. Besides the 4-pin, I know there's an air intake temp sensor. Are there any others, and are their resistance/temp values the same?

Regarding the thermostat, I'm not able to confirm which one was used just yet, as the mechanic is on vacation this week.

Thanks again!

Two others:

1) one-pin sensor located at about cyl 5 for temp gauge in instrument cluster P/N 005-542-26-17
2) two-pin sensor located at about cyl 4 for high speed auxiliary fan P/N 008-542-45-17.

AFAIK, only the 4-pin coolant sensor and the intake air sensor (007-542-21-17) use the resistance/temp scale shown in the FSM.

__________________
1988 California version 260E (W124)
Anthracite Grey/Palomino
Owned since new and still going strong and smooth
MBCA member

Past Mercedes-Benz:
1986 190E Baby Benz
1967 230 Inherited from mom when she downsized
1959 220S Introduced me to the joys of keepin' 'em goin'

There are only 10 kinds of people in the world--those who understand binary and those who don't

Hi guys,

I finally had a chance to check out the air intake and coolant temp sensors this evening. The readings were in line with the resistance values posted elsewhere in the forums.

I also re-checked the duty cycle and it was the same as I had set it before (~50%, oscillating) both at idle and at 2500rpm. Vacuum connections and lines checked out ok with the mity-vac.

I swapped out the O2 sensor about a year ago and it appears to still be working according to the multimeter readings. The IACV is functioning and I resoldered the connections in the OVP a year or so ago.

What else could cause such a huge drop in economy? I'd appreciate any ideas on what else I could look into. I'm thinking clogged fuel filter, leaking EHA, injectors, or cold start valve? I'm going to pull the spark plugs tomorrow to see if they have anything to say.

Thanks for any input you might have!

p.s The car doesn't have cold or hot start issues, though it burps once in a while when idle. Also, no black smoke. The car seems to run fine save for the economy issue. Thanks!