What sensor is this?
 

Can someone identify this sensor for me? It's the first sensor on the cylinderhead of a 86 300E, it's red in color, has two prongs and it looks like vacuum lines connect to it. The reason that I ask is, one of the prongs broke and I need to replace this sensor..

That is a "thermo-vacuum" valve! At 50C this valve allows vacuum to pass thru. Part number is 000-140-71-60 OR 000-140-72-60.

Thermo-valve for fuel vapor purging (red, 50deg C).

This valve, which is closed below 50deg C, transmits vacuum at all throttle positions above idle to the purge valve which allows fuel vapors which have been gathered in the charcoal canister to be pulled with air into the intake for burning. The thermo valve is a temperature controlled on/off switch to the purge vacuum control signal.

Interesting!
 

What symptoms would the car have if it is malfunctioning, if any?
Thanks!:confused:

Its conceivable that an unpurged charcoal cannister could reach its dew point and leak raw fuel. Probably would be so slight that all that would be noticed would be the fuel smell (which is the purpose of the system in the first place).

Thanx for the replys

Hello board:

Does anyone know the location of the thermovalve on later M103's? ('91) It has been modified to 70c and MOVED from front of head to unknown location. In place of former thermovalve on my engine head is the coolant bleed screw. CD's and search are of no help.

TIA!

thermovalve?
 

84 380 SE
i've got a fitting into the engine about 3" to the left of the idle air control valve. the fitting has two small red vacuum line tits and no electrical connections. the tit for the line that goes to the back of the idle air control valve is broken off. small vacuum hose to ICV has been plugged with a BB. Would this explain poor engine idle when engine is cold? Engine seems to run fine when warmed up. Is this a thermovalve or just a fitting for engine vacuum? does anyone have a part number, can't seem to find it on-line.