W116, Specialty Tools

$128.50

123 126 Diesel Transmission Ultimate Diagnostic and Tuning Kit

116 and 126 1978 to 1984 300SD, 1980 to 1984 123 240D and 1981 to 1985 123 Turbo 300D 300TD 300D 300CD. Does not apply to the 722.4 transmissions found in most 1985 models

Transmission

Checking Automatic Transmission Fluid Level

There is a proper way to do this to determine proper level inside transmission

1978 450 SEL High Idle 2000 RPM

I have just acquired a 1978 450 SEL and based on the records the motor has about 35k miles on it since a complete rebuild. It starts up and runs fine (wants to die if you give it gas when cold) once warm. It drives great but the idle is high at about 2000 RPM cold and 1700-1800 warm. Not sure where to start.

Vacuum? Is there an idle control of some sort that could be bad?

I don't see an idle adjustment and don't know these gas engines so I'm lost.

Thanks for any help!

-Mark