My 1991 420 SEL has a little temp guage quirk, started today. Engine cold, start car, temp guage goes immediately to 80+ (C).
It then goes up a little as the engine works.

Normally of course it would be at 0, just below 40 (C) then stay somewhere between the 60 - 80 range (C).

I'm thinking possible temp sender? Maybe a static resistance reading on the sender that I can measure. Possibly beginning to fail and using the 80 mark as a starting point?

Any experiences with this issue?

thanks..... s-ball

80*C is the ideal normal operating tempreture. Don't see any problems.

I think our friend is saying that the gauge reads 80C when first started in the morning.

Check that there's a good connection between the wire and the sensor and maybe pull the sensor and clean the threads on the sensor side and engine side to make sure there's a good ground path. No sealant, thread lock or teflon tape.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

right you are SIXTO:

It starts at 80 when cold.

I'm looking into fasteners at connection and threads into block.
thanks.

s-ball

Here is that info: [ single wire sensor-read from terminal to ground].

60C-110 ohm
80C-67 ohm
100C-38 ohm

THANKS TO ALL.....

dirty connection points created additional resistance which created an improper signal

problem now solved

s-ball

You can always count on Arthur to have ESP and to have a mind like a steel trap.

I don't know how he remembers all those numbers!

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".