W116.org

I'm thinking about getting a new instrument panel for my 450SE. The Oil pressure and Thermostat gauges don't seem to be working (Upon starting, Oil pressure jumps to the maximum and stays there, and the Thermostat either reads normal or reads overheating, depending on how many times I tap its plastic cover), and the Speedometer and Rev counter 'bob up and down' uncontrollably when accelerating.

Is the instrument panel from the R107 SL Roadster identical to that my '74 450SE? If so, what year model should I look for?
May head out to a salvage yard tomorrow to search for one.

You can just replace the combination guage, no need to replace the whole thing. I would imagine a 107 part would be the same as long as it is a 1970's car. The 80's cars have the economy guage.

The oil pressure guage is supposed to peg itself upon startup. If it doesn't, you have oil pressure problems.

The issue with the speedo relates to the cable rather than the actual speedo and the tachometer bouncing means it just needs new capacitors or there is a bad connection.

Tim

That's good. There are a lot of good R107's still around. However, most of them may be 80's versions. Oh well, the economy gauge would be a good inside joke.

The oil pressure often stays at maximum. Sometimes for more than 30 minutes before it finally lowers to more 'reasonable' readings. Oh well, I'm not very experienced with these cars yet. I guess it's normal?

I tried pulling the panel out, but it wouldn't come all the way out. Something is caught on it. I remember reaching back there and feeling the speedo cable to be very moist with an oily liquid. Could this be the problem?

Also, the tachometer seems to be fine now. Only then engine rev's up to 2,000+ rpm upon start up, without me doing anything, if it's a bit cold.

you cant use the speedo from the 80's 107s, ie, the ones with the w126 style engines and transmissions.

Why?

They're electronic on 126 era cars, cable operated on 116's etc.

Careful there!  That is a genuine pressure gauge you've got in the dash - with a REAL oil line carrying REAL oil...  and nothing spoils the MB moment like getting oil all over your trousers on your way to the Symphony... 

Speedos tend to bounce after the cluster has been out a few times as you have to stretch the cable a good bit to get a hand back there to loosen it.  Pull it out the absolute minimum anytime you must service the dash array.

Yeah, I'm not gonna touch those dials anymore. Changing them sounds difficult, and risky for a daily driver car.
I'm just worried about those oil and temp gauges. They take far too long to unstick themselves from maximum before showing more normal readings.